win: fix Defender service #128 #385 #393 #402 #426

This commit adds disabling missing low-level Defender service/drivers,
improve disabling existing ones, and improve their documentation.

Key changes:

- Add disabling missing Defender services.
- Add disabling missing Defender processes.
- Add soft-deleting of missing service files
- Fix `ServiceKeepAlive` value #393, #426
- Add disabling system modification restrictions for persistent Disable
  service disabling.
- Recommend more Defender scripts on 'Strict' level

Other supporting changes:

- Add more documentation for related scripts.
- Move disabling `SecHealthUI` to disabling Windows Security.
- Fix `DisableService` attempting to disable the service even though its
  disabled.
- Add ability to disable service on revert in
  `DisableServiceInRegistry`.
- Improve categorization for simplicity, add new categories for new
  scripts.
- Add ability to run `DeleteRegistryValue` as `TrustedInstaller`.
- Rename some scripts/categories for simplicity and clarity.

.github/actions/install-imagemagick/action.yml

@@ -0,0 +1,12 @@
+inputs:
+  project-root:
+    required: false
+    default: '.'
+runs:
+  using: composite
+  steps:
+    -
+      name: Install ImageMagick
+      shell: bash
+      run: ./.github/actions/install-imagemagick/install-imagemagick.sh
+      working-directory: ${{ inputs.project-root }}

.github/actions/install-imagemagick/install-imagemagick.sh

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+
+main() {
+  local install_command
+  if ! install_command=$(get_install_command); then
+    fatal_error 'Could not find available command to install'
+  fi
+  if ! eval "$install_command"; then
+    echo "Failed to install ImageMagick. Command: ${install_command}"
+    exit 1
+  fi
+  echo 'ImageMagick installation completed successfully'
+}
+
+get_install_command() {
+  case "$OSTYPE" in
+    darwin*)
+      ensure_command_exists 'brew'
+      echo 'brew install imagemagick'
+      ;;
+    linux-gnu*)
+      if is_ubuntu; then
+        ensure_command_exists 'apt'
+        echo 'sudo apt install -y imagemagick'
+      else
+        fatal_error 'Unsupported Linux distribution'
+      fi
+      ;;
+    msys*|cygwin*)
+      ensure_command_exists 'choco'
+      echo 'choco install -y imagemagick'
+      ;;
+    *)
+      fatal_error "Unsupported operating system: $OSTYPE"
+      ;;
+  esac
+}
+
+ensure_command_exists() {
+  local -r command="$1"
+  if ! command -v "$command" >/dev/null 2>&1; then
+    fatal_error "Command missing: $command"
+  fi
+}
+
+fatal_error() {
+  local -r error_message="$1"
+  >&2 echo "❌ $error_message"
+  exit 1
+}
+
+is_ubuntu() {
+  [ -f /etc/os-release ] && grep -qi 'ubuntu' /etc/os-release
+}
+
+main

.github/workflows/checks.desktop-runtime-errors.yaml

@@ -26,9 +26,12 @@ jobs:
       -
         name: Install dependencies
         uses: ./.github/actions/npm-install-dependencies
+      -
+        name: Install ImageMagick # For screenshots
+        uses: ./.github/actions/install-imagemagick
       -
         name: Configure Ubuntu
-        if: contains(matrix.os, 'ubuntu') # macOS runner is missing Docker
+        if: contains(matrix.os, 'ubuntu')
         shell: bash
         run: |-
           sudo apt update
@@ -56,11 +59,20 @@ jobs:
           sudo Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
           echo "DISPLAY=:99" >> $GITHUB_ENV
 
-          # Install ImageMagick for screenshots
-          sudo apt install -y imagemagick
-
           # Install xdotool and xprop (from x11-utils) for window title capturing
           sudo apt install -y xdotool x11-utils
+
+          # Workaround for Electron AppImage apps failing to initialize on Ubuntu 24.04 due to AppArmor restrictions
+          # Disables unprivileged user namespaces restriction to allow Electron apps to run
+          # Reference: https://github.com/electron/electron/issues/42510
+          sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0
+
+          # Workaround for Mesa driver issues on Ubuntu 24.04
+          # Installs latest Mesa drivers from Kisak PPA
+          # Reference: https://askubuntu.com/q/1516040
+          sudo add-apt-repository ppa:kisak/kisak-mesa
+          sudo apt update
+          sudo apt upgrade
       -
         name: Test
         shell: bash

.github/workflows/checks.quality.yaml

@@ -11,8 +11,9 @@ jobs:
           - npm run lint:eslint
           - npm run lint:yaml
           - npm run lint:md
-          - npm run lint:md:relative-urls
           - npm run lint:md:consistency
+          - npm run lint:md:relative-urls
+          - npm run lint:md:external-urls
         os: [ macos, ubuntu, windows ]
       fail-fast: false # Still interested to see results from other combinations
     steps:

.github/workflows/checks.scripts.yaml

@@ -9,16 +9,15 @@ jobs:
     runs-on: ${{ matrix.os }}-latest
     strategy:
       matrix:
-        os: [ macos, ubuntu, windows ]
+        os: [macos, ubuntu, windows]
       fail-fast: false # Still interested to see results from other combinations
     steps:
       -
         name: Checkout
         uses: actions/checkout@v4
       -
-        name: Install ImageMagick on macOS
+        name: Install ImageMagick
-        if: matrix.os == 'macos'
+        uses: ./.github/actions/install-imagemagick
-        run: brew install imagemagick
       -
         name: Setup node
         uses: ./.github/actions/setup-node

CHANGELOG.md

@@ -1,5 +1,38 @@
 # Changelog
 
+## 0.13.6 (2024-08-13)
+
+* win: improve service disabling as TrustedInstaller | [5d365f6](https://github.com/undergroundwires/privacy.sexy/commit/5d365f65fa0e34925b16b2eac2af53c31e34e99a)
+* Fix documentation button spacing on small screens | [70959cc](https://github.com/undergroundwires/privacy.sexy/commit/70959ccadafac5abcfa83e90cdb0537890b05f14)
+* Fix close button overlap by scrollbar | [19ea8db](https://github.com/undergroundwires/privacy.sexy/commit/19ea8dbc5bc2dc436200cd40bf2a84c3fc3c6471)
+* win: refactor version-specific actions | [0239b52](https://github.com/undergroundwires/privacy.sexy/commit/0239b523859d5c2b80033cc03f0248a9af35f28f)
+* win: support Microsoft Store Firefox installations | [8d7a7eb](https://github.com/undergroundwires/privacy.sexy/commit/8d7a7eb434b2d83e32fa758db7e6798849bad41c)
+* Refactor text utilities and expand their usage | [851917e](https://github.com/undergroundwires/privacy.sexy/commit/851917e049c41c679644ddbe8ad4b6e45e5c8f35)
+* Bump dependencies to latest | [dd7239b](https://github.com/undergroundwires/privacy.sexy/commit/dd7239b8c14027274926279a4c8c7e5845b55558)
+* Refactor styles to match new CSS nesting behavior | [abe03ce](https://github.com/undergroundwires/privacy.sexy/commit/abe03cef3f691f6e56faee991cd2da9c45244279)
+* Improve compiler error display for latest Chromium | [b16e136](https://github.com/undergroundwires/privacy.sexy/commit/b16e13678ce1b8a6871eba8196e82bb321410067)
+* Fix intermittent `ModalDialog` unit test failures | [a650558](https://github.com/undergroundwires/privacy.sexy/commit/a6505587bf4a448f5f3de930004a95ee203416b8)
+* Ensure tests do not log warning or errors | [ae0165f](https://github.com/undergroundwires/privacy.sexy/commit/ae0165f1fe7dba9dd8ddaa1afa722a939772d3b6)
+* win: improve disabling SmartScreen #385 | [11e566d](https://github.com/undergroundwires/privacy.sexy/commit/11e566d0e5177214a2600f3fd2097aea62373b24)
+* win: unify registry setting as TrustedInstaller | [8526d25](https://github.com/undergroundwires/privacy.sexy/commit/8526d2510b34cbd7e79342f79d444419f601b186)
+* win: improve, fix, restructure CEIP disabling | [c2d3cdd](https://github.com/undergroundwires/privacy.sexy/commit/c2d3cddc47d8d4b34bff63d959612919fa971012)
+* win: centralize, improve Defender data collection | [b185255](https://github.com/undergroundwires/privacy.sexy/commit/b185255a0a72d5bfa96d6cf60f868ecc67149d68)
+* win: fix and document VStudio license removal | [109fc01](https://github.com/undergroundwires/privacy.sexy/commit/109fc01c9a047002c4309e7f8a2ca4647c494a8a)
+* win: improve registry/recent cleaning | [48d97af](https://github.com/undergroundwires/privacy.sexy/commit/48d97afdf6c2964cab7951208e1b0a02c3fd4c9b)
+* Relax linting to allow null recommendation | [6fbc816](https://github.com/undergroundwires/privacy.sexy/commit/6fbc81675f7f063c4ee2502b8d9f169aacb39ae4)
+* Refactor executable IDs to use strings #262 | [ded55a6](https://github.com/undergroundwires/privacy.sexy/commit/ded55a66d6044a03d4e18330e146b69d159509a3)
+* win: fix, improve and unify Windows version logic | [f89c232](https://github.com/undergroundwires/privacy.sexy/commit/f89c2322b05d19b82914b20416ecefd7bc7e3702)
+* Fix PowerShell code block inlining in compiler | [d77c3cb](https://github.com/undergroundwires/privacy.sexy/commit/d77c3cbbe212d9929e083181cc331b45d01e2883)
+* win: improve registry value deletion #381 | [55c23e9](https://github.com/undergroundwires/privacy.sexy/commit/55c23e9d4cee3b7f74c26a4ac8516535048d67f2)
+* win: improve folder hiding in "This PC" #16 | [e8add5e](https://github.com/undergroundwires/privacy.sexy/commit/e8add5ec08d2e8b7636cc9c8f0f9a33e4b004265)
+* win: improve Microsoft Edge associations removal | [c2f4b68](https://github.com/undergroundwires/privacy.sexy/commit/c2f4b6878635e97f9c4be7bf2ee194a2deebb38a)
+* win: unify registry data setting, fix #380 | [4cea6b2](https://github.com/undergroundwires/privacy.sexy/commit/4cea6b26ec2717c792c2471cc587f370274f90c4)
+* win: improve disabling NCSI #189, #216, #279 | [c7e57b8](https://github.com/undergroundwires/privacy.sexy/commit/c7e57b8913f409a1c149ba598dc2f8786df0f9a9)
+* win, mac: fix minor typos, formatting, dead URLs | [29e1069](https://github.com/undergroundwires/privacy.sexy/commit/29e1069bf2bc317e3c255b38c1ba0ab078b42d98)
+* win: fix, constrain and document WNS #227 #314 | [50ba00b](https://github.com/undergroundwires/privacy.sexy/commit/50ba00b0af6232fc9187532635b04c4d9d9a68af)
+
+[compare](https://github.com/undergroundwires/privacy.sexy/compare/0.13.5...0.13.6)
+
 ## 0.13.5 (2024-06-26)
 
 * ci/cd: centralize and bump artifact uploads | [22d6c79](https://github.com/undergroundwires/privacy.sexy/commit/22d6c7991eb2c138578a7d41950f301906dbf703)

README.md

@@ -122,7 +122,7 @@
 ## Get started
 
 - 🌍️ **Online**: [https://privacy.sexy](https://privacy.sexy).
-- 🖥️ **Offline**: Download directly for: [Windows](https://github.com/undergroundwires/privacy.sexy/releases/download/0.13.5/privacy.sexy-Setup-0.13.5.exe), [macOS](https://github.com/undergroundwires/privacy.sexy/releases/download/0.13.5/privacy.sexy-0.13.5.dmg), [Linux](https://github.com/undergroundwires/privacy.sexy/releases/download/0.13.5/privacy.sexy-0.13.5.AppImage). For more options, see [here](#additional-install-options).
+- 🖥️ **Offline**: Download directly for: [Windows](https://github.com/undergroundwires/privacy.sexy/releases/download/0.13.6/privacy.sexy-Setup-0.13.6.exe), [macOS](https://github.com/undergroundwires/privacy.sexy/releases/download/0.13.6/privacy.sexy-0.13.6.dmg), [Linux](https://github.com/undergroundwires/privacy.sexy/releases/download/0.13.6/privacy.sexy-0.13.6.AppImage). For more options, see [here](#additional-install-options).
 
 See also:
 

docs/desktop/desktop-vs-web-features.md

@@ -34,8 +34,10 @@ The desktop version ensures secure delivery through cryptographic signatures and
 
 [Security is a top priority](./../../SECURITY.md#update-security-and-integrity) at privacy.sexy.
 
-> **Note for macOS users:** On macOS, the desktop version's auto-update process involves manual steps due to Apple's code signing costs.
+> **Note for macOS users:**
+> On macOS, the desktop version's auto-update process involves manual steps due to Apple's code signing costs.
 > Users get notified about updates but might need to complete the installation manually.
+> Updater stores update installation files temporarily at `$HOME/Library/Application Support/privacy.sexy/updates`.
 > Consider [donating](https://github.com/sponsors/undergroundwires) to help improve this process ❤️.
 
 ### Logging

docs/development.md

@@ -39,6 +39,7 @@ See [ci-cd.md](./ci-cd.md) for more information.
 - Markdown: `npm run lint:md`
 - Markdown consistency `npm run lint:md:consistency`
 - Markdown relative URLs: `npm run lint:md:relative-urls`
+- Markdown external URLs: `npm run lint:md:external-urls`
 - JavaScript/TypeScript: `npm run lint:eslint`
 - Yaml: `npm run lint:yaml`
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "privacy.sexy",
-  "version": "0.13.5",
+  "version": "0.13.6",
   "private": true,
   "slogan": "Privacy is sexy",
   "description": "Enforce privacy & security best-practices on Windows, macOS and Linux, because privacy is sexy.",
@@ -14,7 +14,7 @@
     "test:integration": "vitest run --dir tests/integration",
     "test:cy:run": "start-server-and-test \"vite build && vite preview --port 7070\" http://localhost:7070 \"cypress run --config baseUrl=http://localhost:7070\"",
     "test:cy:open": "start-server-and-test \"vite --port 7070 --mode production\" http://localhost:7070 \"cypress open --config baseUrl=http://localhost:7070\"",
-    "lint": "npm run lint:md && npm run lint:md:consistency && npm run lint:md:relative-urls && npm run lint:eslint && npm run lint:yaml && npm run lint:pylint",
+    "lint": "npm run lint:md && npm run lint:md:consistency && npm run lint:md:relative-urls && npm run lint:md:external-urls && npm run lint:eslint && npm run lint:yaml && npm run lint:pylint",
     "install-deps": "node scripts/npm-install.js",
     "icons:build": "node scripts/logo-update.js",
     "check:desktop": "vitest run --dir tests/checks/desktop-runtime-errors --environment node",
@@ -28,6 +28,7 @@
     "lint:md": "markdownlint **/*.md --ignore node_modules",
     "lint:md:consistency": "remark . --frail --use remark-preset-lint-consistent",
     "lint:md:relative-urls": "remark . --frail --use remark-validate-links",
+    "lint:md:external-urls": "remark . --frail --use remark-lint-no-dead-urls",
     "lint:yaml": "yamllint **/*.yaml --ignore=node_modules/**/*.yaml",
     "lint:pylint": "pylint **/*.py",
     "postinstall": "electron-builder install-app-deps",
@@ -71,15 +72,15 @@
     "markdownlint-cli": "^0.41.0",
     "postcss": "^8.4.39",
     "remark-cli": "^12.0.1",
-    "remark-lint-no-dead-urls": "^1.1.0",
+    "remark-lint-no-dead-urls": "^2.0.0",
     "remark-preset-lint-consistent": "^6.0.0",
     "remark-validate-links": "^13.0.1",
-    "sass": "^1.77.8",
+    "sass": "~1.79.4",
     "start-server-and-test": "^2.0.4",
     "terser": "^5.31.3",
     "tslib": "^2.6.3",
-    "typescript": "^5.4.5",
+    "typescript": "~5.5.4",
-    "vite": "^5.3.4",
+    "vite": "^5.4.8",
     "vitest": "^2.0.3",
     "vue-tsc": "^2.0.26",
     "yaml-lint": "^1.7.0"

src/application/Common/Enum.ts

@@ -33,23 +33,25 @@ function parseEnumValue<T extends EnumType, TEnumValue extends EnumType>(
   if (!casedValue) {
     throw new Error(`unknown ${enumName}: "${value}"`);
   }
-  return enumVariable[casedValue as keyof typeof enumVariable];
+  return enumVariable[casedValue as keyof EnumVariable<T, TEnumValue>];
 }
 
 export function getEnumNames
 <T extends EnumType, TEnumValue extends EnumType>(
   enumVariable: EnumVariable<T, TEnumValue>,
-): string[] {
+): (string & keyof EnumVariable<T, TEnumValue>)[] {
   return Object
     .values(enumVariable)
-    .filter((enumMember): enumMember is string => isString(enumMember));
+    .filter((
+      enumMember,
+    ): enumMember is string & (keyof EnumVariable<T, TEnumValue>) => isString(enumMember));
 }
 
 export function getEnumValues<T extends EnumType, TEnumValue extends EnumType>(
   enumVariable: EnumVariable<T, TEnumValue>,
 ): TEnumValue[] {
   return getEnumNames(enumVariable)
-    .map((level) => enumVariable[level]) as TEnumValue[];
+    .map((name) => enumVariable[name]) as TEnumValue[];
 }
 
 export function assertInRange<T extends EnumType, TEnumValue extends EnumType>(

src/application/Context/ApplicationContext.ts

@@ -17,7 +17,7 @@ export class ApplicationContext implements IApplicationContext {
   public currentOs: OperatingSystem;
 
   public get state(): ICategoryCollectionState {
-    return this.states[this.collection.os];
+    return this.getState(this.collection.os);
   }
 
   private readonly states: StateMachine;
@@ -26,30 +26,51 @@ export class ApplicationContext implements IApplicationContext {
     public readonly app: IApplication,
     initialContext: OperatingSystem,
   ) {
+    this.setContext(initialContext);
     this.states = initializeStates(app);
-    this.changeContext(initialContext);
   }
 
   public changeContext(os: OperatingSystem): void {
-    assertInRange(os, OperatingSystem);
     if (this.currentOs === os) {
       return;
     }
-    const collection = this.app.getCollection(os);
-    this.collection = collection;
     const event: IApplicationContextChangedEvent = {
-      newState: this.states[os],
+      newState: this.getState(os),
-      oldState: this.states[this.currentOs],
+      oldState: this.getState(this.currentOs),
     };
+    this.setContext(os);
     this.contextChanged.notify(event);
+  }
+
+  private setContext(os: OperatingSystem): void {
+    validateOperatingSystem(os, this.app);
+    this.collection = this.app.getCollection(os);
     this.currentOs = os;
   }
+
+  private getState(os: OperatingSystem): ICategoryCollectionState {
+    const state = this.states.get(os);
+    if (!state) {
+      throw new Error(`Operating system "${OperatingSystem[os]}" state is unknown.`);
+    }
+    return state;
+  }
+}
+
+function validateOperatingSystem(
+  os: OperatingSystem,
+  app: IApplication,
+): void {
+  assertInRange(os, OperatingSystem);
+  if (!app.getSupportedOsList().includes(os)) {
+    throw new Error(`Operating system "${OperatingSystem[os]}" is not supported.`);
+  }
 }
 
 function initializeStates(app: IApplication): StateMachine {
   const machine = new Map<OperatingSystem, ICategoryCollectionState>();
   for (const collection of app.collections) {
-    machine[collection.os] = new CategoryCollectionState(collection);
+    machine.set(collection.os, new CategoryCollectionState(collection));
   }
   return machine;
 }

src/application/Parser/CategoryCollectionParser.ts

@@ -7,7 +7,7 @@ import { createEnumParser, type EnumParser } from '../Common/Enum';
 import { parseCategory, type CategoryParser } from './Executable/CategoryParser';
 import { parseScriptingDefinition, type ScriptingDefinitionParser } from './ScriptingDefinition/ScriptingDefinitionParser';
 import { createTypeValidator, type TypeValidator } from './Common/TypeValidator';
-import { createCollectionUtilities, type CategoryCollectionSpecificUtilitiesFactory } from './Executable/CategoryCollectionSpecificUtilities';
+import { createCategoryCollectionContext, type CategoryCollectionContextFactory } from './Executable/CategoryCollectionContext';
 
 export const parseCategoryCollection: CategoryCollectionParser = (
   content,
@@ -16,9 +16,9 @@ export const parseCategoryCollection: CategoryCollectionParser = (
 ) => {
   validateCollection(content, utilities.validator);
   const scripting = utilities.parseScriptingDefinition(content.scripting, projectDetails);
-  const collectionUtilities = utilities.createUtilities(content.functions, scripting);
+  const collectionContext = utilities.createContext(content.functions, scripting.language);
   const categories = content.actions.map(
-    (action) => utilities.parseCategory(action, collectionUtilities),
+    (action) => utilities.parseCategory(action, collectionContext),
   );
   const os = utilities.osParser.parseEnum(content.os, 'os');
   const collection = utilities.createCategoryCollection({
@@ -60,7 +60,7 @@ interface CategoryCollectionParserUtilities {
   readonly osParser: EnumParser<OperatingSystem>;
   readonly validator: TypeValidator;
   readonly parseScriptingDefinition: ScriptingDefinitionParser;
-  readonly createUtilities: CategoryCollectionSpecificUtilitiesFactory;
+  readonly createContext: CategoryCollectionContextFactory;
   readonly parseCategory: CategoryParser;
   readonly createCategoryCollection: CategoryCollectionFactory;
 }
@@ -69,7 +69,7 @@ const DefaultUtilities: CategoryCollectionParserUtilities = {
   osParser: createEnumParser(OperatingSystem),
   validator: createTypeValidator(),
   parseScriptingDefinition,
-  createUtilities: createCollectionUtilities,
+  createContext: createCategoryCollectionContext,
   parseCategory,
   createCategoryCollection: (...args) => new CategoryCollection(...args),
 };

src/application/Parser/Executable/CategoryCollectionContext.ts

@@ -0,0 +1,33 @@
+import type { FunctionData } from '@/application/collections/';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import { createScriptCompiler, type ScriptCompilerFactory } from './Script/Compiler/ScriptCompilerFactory';
+import type { ScriptCompiler } from './Script/Compiler/ScriptCompiler';
+
+export interface CategoryCollectionContext {
+  readonly compiler: ScriptCompiler;
+  readonly language: ScriptingLanguage;
+}
+
+export interface CategoryCollectionContextFactory {
+  (
+    functionsData: ReadonlyArray<FunctionData> | undefined,
+    language: ScriptingLanguage,
+    compilerFactory?: ScriptCompilerFactory,
+  ): CategoryCollectionContext;
+}
+
+export const createCategoryCollectionContext: CategoryCollectionContextFactory = (
+  functionsData: ReadonlyArray<FunctionData> | undefined,
+  language: ScriptingLanguage,
+  compilerFactory: ScriptCompilerFactory = createScriptCompiler,
+) => {
+  return {
+    compiler: compilerFactory({
+      categoryContext: {
+        functions: functionsData ?? [],
+        language,
+      },
+    }),
+    language,
+  };
+};

src/application/Parser/Executable/CategoryCollectionSpecificUtilities.ts

@@ -1,35 +0,0 @@
-import type { IScriptingDefinition } from '@/domain/IScriptingDefinition';
-import type { FunctionData } from '@/application/collections/';
-import { ScriptCompiler } from './Script/Compiler/ScriptCompiler';
-import { SyntaxFactory } from './Script/Validation/Syntax/SyntaxFactory';
-import type { IScriptCompiler } from './Script/Compiler/IScriptCompiler';
-import type { ILanguageSyntax } from './Script/Validation/Syntax/ILanguageSyntax';
-import type { ISyntaxFactory } from './Script/Validation/Syntax/ISyntaxFactory';
-
-export interface CategoryCollectionSpecificUtilities {
-  readonly compiler: IScriptCompiler;
-  readonly syntax: ILanguageSyntax;
-}
-
-export const createCollectionUtilities: CategoryCollectionSpecificUtilitiesFactory = (
-  functionsData: ReadonlyArray<FunctionData> | undefined,
-  scripting: IScriptingDefinition,
-  syntaxFactory: ISyntaxFactory = new SyntaxFactory(),
-) => {
-  const syntax = syntaxFactory.create(scripting.language);
-  return {
-    compiler: new ScriptCompiler({
-      functions: functionsData ?? [],
-      syntax,
-    }),
-    syntax,
-  };
-};
-
-export interface CategoryCollectionSpecificUtilitiesFactory {
-  (
-    functionsData: ReadonlyArray<FunctionData> | undefined,
-    scripting: IScriptingDefinition,
-    syntaxFactory?: ISyntaxFactory,
-  ): CategoryCollectionSpecificUtilities;
-}

src/application/Parser/Executable/CategoryParser.ts

@@ -9,16 +9,16 @@ import { parseDocs, type DocsParser } from './DocumentationParser';
 import { parseScript, type ScriptParser } from './Script/ScriptParser';
 import { createExecutableDataValidator, type ExecutableValidator, type ExecutableValidatorFactory } from './Validation/ExecutableValidator';
 import { ExecutableType } from './Validation/ExecutableType';
-import type { CategoryCollectionSpecificUtilities } from './CategoryCollectionSpecificUtilities';
+import type { CategoryCollectionContext } from './CategoryCollectionContext';
 
 export const parseCategory: CategoryParser = (
   category: CategoryData,
-  collectionUtilities: CategoryCollectionSpecificUtilities,
+  collectionContext: CategoryCollectionContext,
   categoryUtilities: CategoryParserUtilities = DefaultCategoryParserUtilities,
 ) => {
   return parseCategoryRecursively({
     categoryData: category,
-    collectionUtilities,
+    collectionContext,
     categoryUtilities,
   });
 };
@@ -26,14 +26,14 @@ export const parseCategory: CategoryParser = (
 export interface CategoryParser {
   (
     category: CategoryData,
-    collectionUtilities: CategoryCollectionSpecificUtilities,
+    collectionContext: CategoryCollectionContext,
     categoryUtilities?: CategoryParserUtilities,
   ): Category;
 }
 
 interface CategoryParseContext {
   readonly categoryData: CategoryData;
-  readonly collectionUtilities: CategoryCollectionSpecificUtilities;
+  readonly collectionContext: CategoryCollectionContext;
   readonly parentCategory?: CategoryData;
   readonly categoryUtilities: CategoryParserUtilities;
 }
@@ -52,7 +52,7 @@ function parseCategoryRecursively(
       children,
       parent: context.categoryData,
       categoryUtilities: context.categoryUtilities,
-      collectionUtilities: context.collectionUtilities,
+      collectionContext: context.collectionContext,
     });
   }
   try {
@@ -82,7 +82,7 @@ function ensureValidCategory(
   });
   validator.assertType((v) => v.assertObject({
     value: category,
-    valueName: `Category '${category.category}'` ?? 'Category',
+    valueName: category.category ? `Category '${category.category}'` : 'Category',
     allowedProperties: [
       'docs', 'children', 'category',
     ],
@@ -104,7 +104,7 @@ interface ExecutableParseContext {
   readonly data: ExecutableData;
   readonly children: CategoryChildren;
   readonly parent: CategoryData;
-  readonly collectionUtilities: CategoryCollectionSpecificUtilities;
+  readonly collectionContext: CategoryCollectionContext;
   readonly categoryUtilities: CategoryParserUtilities;
 }
 
@@ -124,13 +124,13 @@ function parseUnknownExecutable(context: ExecutableParseContext) {
   if (isCategory(context.data)) {
     const subCategory = parseCategoryRecursively({
       categoryData: context.data,
-      collectionUtilities: context.collectionUtilities,
+      collectionContext: context.collectionContext,
       parentCategory: context.parent,
       categoryUtilities: context.categoryUtilities,
     });
     context.children.subcategories.push(subCategory);
   } else { // A script
-    const script = context.categoryUtilities.parseScript(context.data, context.collectionUtilities);
+    const script = context.categoryUtilities.parseScript(context.data, context.collectionContext);
     context.children.subscripts.push(script);
   }
 }

src/application/Parser/Executable/Script/Compiler/Function/SharedFunctionsParser.ts

@@ -2,14 +2,12 @@ import type {
   FunctionData, CodeInstruction, CodeFunctionData, CallFunctionData,
   CallInstruction, ParameterDefinitionData,
 } from '@/application/collections/';
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
+import { validateCode, type CodeValidator } from '@/application/Parser/Executable/Script/Validation/CodeValidator';
-import { CodeValidator } from '@/application/Parser/Executable/Script/Validation/CodeValidator';
-import { NoEmptyLines } from '@/application/Parser/Executable/Script/Validation/Rules/NoEmptyLines';
-import { NoDuplicatedLines } from '@/application/Parser/Executable/Script/Validation/Rules/NoDuplicatedLines';
-import type { ICodeValidator } from '@/application/Parser/Executable/Script/Validation/ICodeValidator';
 import { isArray, isNullOrUndefined, isPlainObject } from '@/TypeHelpers';
 import { wrapErrorWithAdditionalContext, type ErrorWithContextWrapper } from '@/application/Parser/Common/ContextualError';
 import { filterEmptyStrings } from '@/application/Common/Text/FilterEmptyStrings';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import { CodeValidationRule } from '@/application/Parser/Executable/Script/Validation/CodeValidationRule';
 import { createFunctionWithInlineCode, createCallerFunction } from './SharedFunction';
 import { SharedFunctionCollection } from './SharedFunctionCollection';
 import { parseFunctionCalls, type FunctionCallsParser } from './Call/FunctionCallsParser';
@@ -23,14 +21,14 @@ import type { ISharedFunction } from './ISharedFunction';
 export interface SharedFunctionsParser {
   (
     functions: readonly FunctionData[],
-    syntax: ILanguageSyntax,
+    language: ScriptingLanguage,
     utilities?: SharedFunctionsParsingUtilities,
   ): ISharedFunctionCollection;
 }
 
 export const parseSharedFunctions: SharedFunctionsParser = (
   functions: readonly FunctionData[],
-  syntax: ILanguageSyntax,
+  language: ScriptingLanguage,
   utilities = DefaultUtilities,
 ) => {
   const collection = new SharedFunctionCollection();
@@ -39,7 +37,7 @@ export const parseSharedFunctions: SharedFunctionsParser = (
   }
   ensureValidFunctions(functions);
   return functions
-    .map((func) => parseFunction(func, syntax, utilities))
+    .map((func) => parseFunction(func, language, utilities))
     .reduce((acc, func) => {
       acc.addFunction(func);
       return acc;
@@ -49,7 +47,7 @@ export const parseSharedFunctions: SharedFunctionsParser = (
 const DefaultUtilities: SharedFunctionsParsingUtilities = {
   wrapError: wrapErrorWithAdditionalContext,
   parseParameter: parseFunctionParameter,
-  codeValidator: CodeValidator.instance,
+  codeValidator: validateCode,
   createParameterCollection: createFunctionParameterCollection,
   parseFunctionCalls,
 };
@@ -57,20 +55,20 @@ const DefaultUtilities: SharedFunctionsParsingUtilities = {
 interface SharedFunctionsParsingUtilities {
   readonly wrapError: ErrorWithContextWrapper;
   readonly parseParameter: FunctionParameterParser;
-  readonly codeValidator: ICodeValidator;
+  readonly codeValidator: CodeValidator;
   readonly createParameterCollection: FunctionParameterCollectionFactory;
   readonly parseFunctionCalls: FunctionCallsParser;
 }
 
 function parseFunction(
   data: FunctionData,
-  syntax: ILanguageSyntax,
+  language: ScriptingLanguage,
   utilities: SharedFunctionsParsingUtilities,
 ): ISharedFunction {
   const { name } = data;
   const parameters = parseParameters(data, utilities);
   if (hasCode(data)) {
-    validateCode(data, syntax, utilities.codeValidator);
+    validateNonEmptyCode(data, language, utilities.codeValidator);
     return createFunctionWithInlineCode(name, parameters, data.code, data.revertCode);
   }
   // Has call
@@ -78,16 +76,20 @@ function parseFunction(
   return createCallerFunction(name, parameters, calls);
 }
 
-function validateCode(
+function validateNonEmptyCode(
   data: CodeFunctionData,
-  syntax: ILanguageSyntax,
+  language: ScriptingLanguage,
-  validator: ICodeValidator,
+  validate: CodeValidator,
 ): void {
   filterEmptyStrings([data.code, data.revertCode])
     .forEach(
-      (code) => validator.throwIfInvalid(
+      (code) => validate(
         code,
-        [new NoEmptyLines(), new NoDuplicatedLines(syntax)],
+        language,
+        [
+          CodeValidationRule.NoEmptyLines,
+          CodeValidationRule.NoDuplicatedLines,
+        ],
       ),
     );
 }

src/application/Parser/Executable/Script/Compiler/IScriptCompiler.ts

@@ -1,7 +0,0 @@
-import type { ScriptData } from '@/application/collections/';
-import type { ScriptCode } from '@/domain/Executables/Script/Code/ScriptCode';
-
-export interface IScriptCompiler {
-  canCompile(script: ScriptData): boolean;
-  compile(script: ScriptData): ScriptCode;
-}

src/application/Parser/Executable/Script/Compiler/ScriptCompiler.ts

@@ -1,86 +1,7 @@
-import type { FunctionData, ScriptData, CallInstruction } from '@/application/collections/';
+import type { ScriptData } from '@/application/collections/';
 import type { ScriptCode } from '@/domain/Executables/Script/Code/ScriptCode';
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
-import { CodeValidator } from '@/application/Parser/Executable/Script/Validation/CodeValidator';
-import { NoEmptyLines } from '@/application/Parser/Executable/Script/Validation/Rules/NoEmptyLines';
-import type { ICodeValidator } from '@/application/Parser/Executable/Script/Validation/ICodeValidator';
-import { wrapErrorWithAdditionalContext, type ErrorWithContextWrapper } from '@/application/Parser/Common/ContextualError';
-import { createScriptCode, type ScriptCodeFactory } from '@/domain/Executables/Script/Code/ScriptCodeFactory';
-import { filterEmptyStrings } from '@/application/Common/Text/FilterEmptyStrings';
-import { FunctionCallSequenceCompiler } from './Function/Call/Compiler/FunctionCallSequenceCompiler';
-import { parseFunctionCalls } from './Function/Call/FunctionCallsParser';
-import { parseSharedFunctions, type SharedFunctionsParser } from './Function/SharedFunctionsParser';
-import type { CompiledCode } from './Function/Call/Compiler/CompiledCode';
-import type { IScriptCompiler } from './IScriptCompiler';
-import type { ISharedFunctionCollection } from './Function/ISharedFunctionCollection';
-import type { FunctionCallCompiler } from './Function/Call/Compiler/FunctionCallCompiler';
 
-interface ScriptCompilerUtilities {
+export interface ScriptCompiler {
-  readonly sharedFunctionsParser: SharedFunctionsParser;
+  canCompile(script: ScriptData): boolean;
-  readonly callCompiler: FunctionCallCompiler;
+  compile(script: ScriptData): ScriptCode;
-  readonly codeValidator: ICodeValidator;
-  readonly wrapError: ErrorWithContextWrapper;
-  readonly scriptCodeFactory: ScriptCodeFactory;
-}
-
-const DefaultUtilities: ScriptCompilerUtilities = {
-  sharedFunctionsParser: parseSharedFunctions,
-  callCompiler: FunctionCallSequenceCompiler.instance,
-  codeValidator: CodeValidator.instance,
-  wrapError: wrapErrorWithAdditionalContext,
-  scriptCodeFactory: createScriptCode,
-};
-
-interface CategoryCollectionDataContext {
-  readonly functions: readonly FunctionData[];
-  readonly syntax: ILanguageSyntax;
-}
-
-export class ScriptCompiler implements IScriptCompiler {
-  private readonly functions: ISharedFunctionCollection;
-
-  constructor(
-    categoryContext: CategoryCollectionDataContext,
-    private readonly utilities: ScriptCompilerUtilities = DefaultUtilities,
-  ) {
-    this.functions = this.utilities.sharedFunctionsParser(
-      categoryContext.functions,
-      categoryContext.syntax,
-    );
-  }
-
-  public canCompile(script: ScriptData): boolean {
-    return hasCall(script);
-  }
-
-  public compile(script: ScriptData): ScriptCode {
-    try {
-      if (!hasCall(script)) {
-        throw new Error('Script does include any calls.');
-      }
-      const calls = parseFunctionCalls(script.call);
-      const compiledCode = this.utilities.callCompiler.compileFunctionCalls(calls, this.functions);
-      validateCompiledCode(compiledCode, this.utilities.codeValidator);
-      return this.utilities.scriptCodeFactory(
-        compiledCode.code,
-        compiledCode.revertCode,
-      );
-    } catch (error) {
-      throw this.utilities.wrapError(error, `Failed to compile script: ${script.name}`);
-    }
-  }
-}
-
-function validateCompiledCode(compiledCode: CompiledCode, validator: ICodeValidator): void {
-  filterEmptyStrings([compiledCode.code, compiledCode.revertCode])
-    .forEach(
-      (code) => validator.throwIfInvalid(
-        code,
-        [new NoEmptyLines()],
-      ),
-    );
-}
-
-function hasCall(data: ScriptData): data is ScriptData & CallInstruction {
-  return (data as CallInstruction).call !== undefined;
 }

src/application/Parser/Executable/Script/Compiler/ScriptCompilerFactory.ts

@@ -0,0 +1,119 @@
+import type { FunctionData, ScriptData, CallInstruction } from '@/application/collections/';
+import type { ScriptCode } from '@/domain/Executables/Script/Code/ScriptCode';
+import { validateCode, type CodeValidator } from '@/application/Parser/Executable/Script/Validation/CodeValidator';
+import { wrapErrorWithAdditionalContext, type ErrorWithContextWrapper } from '@/application/Parser/Common/ContextualError';
+import { createScriptCode, type ScriptCodeFactory } from '@/domain/Executables/Script/Code/ScriptCodeFactory';
+import { filterEmptyStrings } from '@/application/Common/Text/FilterEmptyStrings';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import { CodeValidationRule } from '@/application/Parser/Executable/Script/Validation/CodeValidationRule';
+import { FunctionCallSequenceCompiler } from './Function/Call/Compiler/FunctionCallSequenceCompiler';
+import { parseFunctionCalls } from './Function/Call/FunctionCallsParser';
+import { parseSharedFunctions, type SharedFunctionsParser } from './Function/SharedFunctionsParser';
+import type { CompiledCode } from './Function/Call/Compiler/CompiledCode';
+import type { ScriptCompiler } from './ScriptCompiler';
+import type { ISharedFunctionCollection } from './Function/ISharedFunctionCollection';
+import type { FunctionCallCompiler } from './Function/Call/Compiler/FunctionCallCompiler';
+
+export interface ScriptCompilerInitParameters {
+  readonly categoryContext: CategoryCollectionDataContext;
+  readonly utilities?: ScriptCompilerUtilities;
+}
+
+export interface ScriptCompilerFactory {
+  (parameters: ScriptCompilerInitParameters): ScriptCompiler;
+}
+
+export const createScriptCompiler: ScriptCompilerFactory = (
+  parameters,
+) => {
+  return new FunctionCallScriptCompiler(
+    parameters.categoryContext,
+    parameters.utilities ?? DefaultUtilities,
+  );
+};
+
+interface ScriptCompilerUtilities {
+  readonly sharedFunctionsParser: SharedFunctionsParser;
+  readonly callCompiler: FunctionCallCompiler;
+  readonly codeValidator: CodeValidator;
+  readonly wrapError: ErrorWithContextWrapper;
+  readonly scriptCodeFactory: ScriptCodeFactory;
+}
+
+const DefaultUtilities: ScriptCompilerUtilities = {
+  sharedFunctionsParser: parseSharedFunctions,
+  callCompiler: FunctionCallSequenceCompiler.instance,
+  codeValidator: validateCode,
+  wrapError: wrapErrorWithAdditionalContext,
+  scriptCodeFactory: createScriptCode,
+};
+
+interface CategoryCollectionDataContext {
+  readonly functions: readonly FunctionData[];
+  readonly language: ScriptingLanguage;
+}
+
+class FunctionCallScriptCompiler implements ScriptCompiler {
+  private readonly functions: ISharedFunctionCollection;
+
+  private readonly language: ScriptingLanguage;
+
+  constructor(
+    categoryContext: CategoryCollectionDataContext,
+    private readonly utilities: ScriptCompilerUtilities = DefaultUtilities,
+  ) {
+    this.functions = this.utilities.sharedFunctionsParser(
+      categoryContext.functions,
+      categoryContext.language,
+    );
+    this.language = categoryContext.language;
+  }
+
+  public canCompile(script: ScriptData): boolean {
+    return hasCall(script);
+  }
+
+  public compile(script: ScriptData): ScriptCode {
+    try {
+      if (!hasCall(script)) {
+        throw new Error('Script does include any calls.');
+      }
+      const calls = parseFunctionCalls(script.call);
+      const compiledCode = this.utilities.callCompiler.compileFunctionCalls(calls, this.functions);
+      validateCompiledCode(
+        compiledCode,
+        this.language,
+        this.utilities.codeValidator,
+      );
+      return this.utilities.scriptCodeFactory(
+        compiledCode.code,
+        compiledCode.revertCode,
+      );
+    } catch (error) {
+      throw this.utilities.wrapError(error, `Failed to compile script: ${script.name}`);
+    }
+  }
+}
+
+function validateCompiledCode(
+  compiledCode: CompiledCode,
+  language: ScriptingLanguage,
+  validate: CodeValidator,
+): void {
+  filterEmptyStrings([compiledCode.code, compiledCode.revertCode])
+    .forEach(
+      (code) => validate(
+        code,
+        language,
+        [
+          CodeValidationRule.NoEmptyLines,
+          CodeValidationRule.NoTooLongLines,
+          // Allow duplicated lines to enable calling same function multiple times
+        ],
+      ),
+    );
+}
+
+function hasCall(data: ScriptData): data is ScriptData & CallInstruction {
+  return (data as CallInstruction).call !== undefined;
+}

src/application/Parser/Executable/Script/ScriptParser.ts

@@ -1,9 +1,7 @@
 import type { ScriptData, CodeScriptData, CallScriptData } from '@/application/collections/';
-import { NoEmptyLines } from '@/application/Parser/Executable/Script/Validation/Rules/NoEmptyLines';
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
 import { RecommendationLevel } from '@/domain/Executables/Script/RecommendationLevel';
 import type { ScriptCode } from '@/domain/Executables/Script/Code/ScriptCode';
-import type { ICodeValidator } from '@/application/Parser/Executable/Script/Validation/ICodeValidator';
+import { validateCode, type CodeValidator } from '@/application/Parser/Executable/Script/Validation/CodeValidator';
 import { wrapErrorWithAdditionalContext, type ErrorWithContextWrapper } from '@/application/Parser/Common/ContextualError';
 import type { ScriptCodeFactory } from '@/domain/Executables/Script/Code/ScriptCodeFactory';
 import { createScriptCode } from '@/domain/Executables/Script/Code/ScriptCodeFactory';
@@ -11,24 +9,24 @@ import type { Script } from '@/domain/Executables/Script/Script';
 import { createEnumParser, type EnumParser } from '@/application/Common/Enum';
 import { filterEmptyStrings } from '@/application/Common/Text/FilterEmptyStrings';
 import { createScript, type ScriptFactory } from '@/domain/Executables/Script/ScriptFactory';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import { CodeValidationRule } from '@/application/Parser/Executable/Script/Validation/CodeValidationRule';
 import { parseDocs, type DocsParser } from '../DocumentationParser';
 import { ExecutableType } from '../Validation/ExecutableType';
 import { createExecutableDataValidator, type ExecutableValidator, type ExecutableValidatorFactory } from '../Validation/ExecutableValidator';
-import { CodeValidator } from './Validation/CodeValidator';
+import type { CategoryCollectionContext } from '../CategoryCollectionContext';
-import { NoDuplicatedLines } from './Validation/Rules/NoDuplicatedLines';
-import type { CategoryCollectionSpecificUtilities } from '../CategoryCollectionSpecificUtilities';
 
 export interface ScriptParser {
   (
     data: ScriptData,
-    collectionUtilities: CategoryCollectionSpecificUtilities,
+    collectionContext: CategoryCollectionContext,
     scriptUtilities?: ScriptParserUtilities,
   ): Script;
 }
 
 export const parseScript: ScriptParser = (
   data,
-  collectionUtilities,
+  collectionContext,
   scriptUtilities = DefaultUtilities,
 ) => {
   const validator = scriptUtilities.createValidator({
@@ -42,7 +40,7 @@ export const parseScript: ScriptParser = (
       name: data.name,
       code: parseCode(
         data,
-        collectionUtilities,
+        collectionContext,
         scriptUtilities.codeValidator,
         scriptUtilities.createCode,
       ),
@@ -70,29 +68,34 @@ function parseLevel(
 
 function parseCode(
   script: ScriptData,
-  collectionUtilities: CategoryCollectionSpecificUtilities,
+  collectionContext: CategoryCollectionContext,
-  codeValidator: ICodeValidator,
+  codeValidator: CodeValidator,
   createCode: ScriptCodeFactory,
 ): ScriptCode {
-  if (collectionUtilities.compiler.canCompile(script)) {
+  if (collectionContext.compiler.canCompile(script)) {
-    return collectionUtilities.compiler.compile(script);
+    return collectionContext.compiler.compile(script);
   }
   const codeScript = script as CodeScriptData; // Must be inline code if it cannot be compiled
   const code = createCode(codeScript.code, codeScript.revertCode);
-  validateHardcodedCodeWithoutCalls(code, codeValidator, collectionUtilities.syntax);
+  validateHardcodedCodeWithoutCalls(code, codeValidator, collectionContext.language);
   return code;
 }
 
 function validateHardcodedCodeWithoutCalls(
   scriptCode: ScriptCode,
-  validator: ICodeValidator,
+  validate: CodeValidator,
-  syntax: ILanguageSyntax,
+  language: ScriptingLanguage,
 ) {
   filterEmptyStrings([scriptCode.execute, scriptCode.revert])
     .forEach(
-      (code) => validator.throwIfInvalid(
+      (code) => validate(
         code,
-        [new NoEmptyLines(), new NoDuplicatedLines(syntax)],
+        language,
+        [
+          CodeValidationRule.NoEmptyLines,
+          CodeValidationRule.NoDuplicatedLines,
+          CodeValidationRule.NoTooLongLines,
+        ],
       ),
     );
 }
@@ -103,7 +106,7 @@ function validateScript(
 ): asserts script is NonNullable<ScriptData> {
   validator.assertType((v) => v.assertObject<CallScriptData & CodeScriptData>({
     value: script,
-    valueName: `Script '${script.name}'` ?? 'Script',
+    valueName: script.name ? `Script '${script.name}'` : 'Script',
     allowedProperties: [
       'name', 'recommend', 'code', 'revertCode', 'call', 'docs',
     ],
@@ -126,7 +129,7 @@ function validateScript(
 interface ScriptParserUtilities {
   readonly levelParser: EnumParser<RecommendationLevel>;
   readonly createScript: ScriptFactory;
-  readonly codeValidator: ICodeValidator;
+  readonly codeValidator: CodeValidator;
   readonly wrapError: ErrorWithContextWrapper;
   readonly createValidator: ExecutableValidatorFactory;
   readonly createCode: ScriptCodeFactory;
@@ -136,7 +139,7 @@ interface ScriptParserUtilities {
 const DefaultUtilities: ScriptParserUtilities = {
   levelParser: createEnumParser(RecommendationLevel),
   createScript,
-  codeValidator: CodeValidator.instance,
+  codeValidator: validateCode,
   wrapError: wrapErrorWithAdditionalContext,
   createValidator: createExecutableDataValidator,
   createCode: createScriptCode,

src/application/Parser/Executable/Script/Validation/Analyzers/AnalyzeDuplicateLines.ts

@@ -0,0 +1,63 @@
+import type { LanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Analyzers/Syntax/LanguageSyntax';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import { createSyntax, type SyntaxFactory } from './Syntax/SyntaxFactory';
+import type { CodeLine, CodeValidationAnalyzer, InvalidCodeLine } from './CodeValidationAnalyzer';
+
+export type DuplicateLinesAnalyzer = CodeValidationAnalyzer & {
+  (
+    ...args: [
+      ...Parameters<CodeValidationAnalyzer>,
+      syntaxFactory?: SyntaxFactory,
+    ]
+  ): ReturnType<CodeValidationAnalyzer>;
+};
+
+export const analyzeDuplicateLines: DuplicateLinesAnalyzer = (
+  lines: readonly CodeLine[],
+  language: ScriptingLanguage,
+  syntaxFactory: SyntaxFactory = createSyntax,
+) => {
+  const syntax = syntaxFactory(language);
+  return lines
+    .map((line): CodeLineWithDuplicateOccurrences => ({
+      lineNumber: line.lineNumber,
+      shouldBeIgnoredInAnalysis: shouldIgnoreLine(line.text, syntax),
+      duplicateLineNumbers: lines
+        .filter((other) => other.text === line.text)
+        .map((duplicatedLine) => duplicatedLine.lineNumber),
+    }))
+    .filter((line) => isNonIgnorableDuplicateLine(line))
+    .map((line): InvalidCodeLine => ({
+      lineNumber: line.lineNumber,
+      error: `Line is duplicated at line numbers ${line.duplicateLineNumbers.join(',')}.`,
+    }));
+};
+
+interface CodeLineWithDuplicateOccurrences {
+  readonly lineNumber: number;
+  readonly duplicateLineNumbers: readonly number[];
+  readonly shouldBeIgnoredInAnalysis: boolean;
+}
+
+function isNonIgnorableDuplicateLine(line: CodeLineWithDuplicateOccurrences): boolean {
+  return !line.shouldBeIgnoredInAnalysis && line.duplicateLineNumbers.length > 1;
+}
+
+function shouldIgnoreLine(codeLine: string, syntax: LanguageSyntax): boolean {
+  return isCommentLine(codeLine, syntax)
+    || isLineComposedEntirelyOfCommonCodeParts(codeLine, syntax);
+}
+
+function isCommentLine(codeLine: string, syntax: LanguageSyntax): boolean {
+  return syntax.commentDelimiters.some(
+    (delimiter) => codeLine.startsWith(delimiter),
+  );
+}
+
+function isLineComposedEntirelyOfCommonCodeParts(
+  codeLine: string,
+  syntax: LanguageSyntax,
+): boolean {
+  const codeLineParts = codeLine.toLowerCase().trim().split(' ');
+  return codeLineParts.every((part) => syntax.commonCodeParts.includes(part));
+}

src/application/Parser/Executable/Script/Validation/Analyzers/AnalyzeEmptyLines.ts

@@ -0,0 +1,24 @@
+import type { CodeValidationAnalyzer, InvalidCodeLine } from './CodeValidationAnalyzer';
+
+export const analyzeEmptyLines: CodeValidationAnalyzer = (
+  lines,
+) => {
+  return lines
+    .filter((line) => isEmptyLine(line.text))
+    .map((line): InvalidCodeLine => ({
+      lineNumber: line.lineNumber,
+      error: (() => {
+        if (!line.text) {
+          return 'Empty line';
+        }
+        const markedText = line.text
+          .replaceAll(' ', '{whitespace}')
+          .replaceAll('\t', '{tab}');
+        return `Empty line: "${markedText}"`;
+      })(),
+    }));
+};
+
+function isEmptyLine(line: string): boolean {
+  return line.trim().length === 0;
+}

src/application/Parser/Executable/Script/Validation/Analyzers/AnalyzeTooLongLines.ts

@@ -0,0 +1,44 @@
+import { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import type { CodeValidationAnalyzer, InvalidCodeLine } from './CodeValidationAnalyzer';
+
+export const analyzeTooLongLines: CodeValidationAnalyzer = (
+  lines,
+  language,
+) => {
+  const maxLineLength = getMaxAllowedLineLength(language);
+  return lines
+    .filter((line) => line.text.length > maxLineLength)
+    .map((line): InvalidCodeLine => ({
+      lineNumber: line.lineNumber,
+      error: [
+        `Line is too long (${line.text.length}).`,
+        `It exceed maximum allowed length ${maxLineLength} by ${line.text.length - maxLineLength} characters.`,
+        'This may cause bugs due to unintended trimming by operating system, shells or terminal emulators.',
+      ].join(' '),
+    }));
+};
+
+function getMaxAllowedLineLength(language: ScriptingLanguage): number {
+  switch (language) {
+    case ScriptingLanguage.batchfile:
+      /*
+        The maximum length of the string that you can use at the command prompt is 8191 characters.
+        https://web.archive.org/web/20240815120224/https://learn.microsoft.com/en-us/troubleshoot/windows-client/shell-experience/command-line-string-limitation
+      */
+      return 8191;
+    case ScriptingLanguage.shellscript:
+      /*
+        Tests show:
+
+        | OS  | Command | Value |
+        | --- | ------- | ----- |
+        | Pop!_OS 22.04                         | xargs --show-limits     | 2088784 |
+        | macOS Sonoma 14.3 on Intel            | getconf ARG_MAX         | 1048576 |
+        | macOS Sonoma 14.3 on Apple Silicon M1 | getconf ARG_MAX         | 1048576 |
+        | Android 12 (4.14.180) with Termux     | xargs --show-limits     | 2087244 |
+      */
+      return 1048576; // Minimum value for reliability
+    default:
+      throw new Error(`Unsupported language: ${ScriptingLanguage[language]} (${language})`);
+  }
+}

src/application/Parser/Executable/Script/Validation/Analyzers/CodeValidationAnalyzer.ts

@@ -0,0 +1,18 @@
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+
+export interface CodeValidationAnalyzer {
+  (
+    lines: readonly CodeLine[],
+    language: ScriptingLanguage,
+  ): InvalidCodeLine[];
+}
+
+export interface InvalidCodeLine {
+  readonly lineNumber: number;
+  readonly error: string;
+}
+
+export interface CodeLine {
+  readonly lineNumber: number;
+  readonly text: string;
+}

src/application/Parser/Executable/Script/Validation/Analyzers/Syntax/BatchFileSyntax.ts

@@ -1,9 +1,9 @@
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
+import type { LanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Analyzers/Syntax/LanguageSyntax';
 
 const BatchFileCommonCodeParts = ['(', ')', 'else', '||'];
 const PowerShellCommonCodeParts = ['{', '}'];
 
-export class BatchFileSyntax implements ILanguageSyntax {
+export class BatchFileSyntax implements LanguageSyntax {
   public readonly commentDelimiters = ['REM', '::'];
 
   public readonly commonCodeParts = [...BatchFileCommonCodeParts, ...PowerShellCommonCodeParts];

src/application/Parser/Executable/Script/Validation/Analyzers/Syntax/LanguageSyntax.ts

@@ -0,0 +1,4 @@
+export interface LanguageSyntax {
+  readonly commentDelimiters: readonly string[];
+  readonly commonCodeParts: readonly string[];
+}

src/application/Parser/Executable/Script/Validation/Analyzers/Syntax/ShellScriptSyntax.ts

@@ -0,0 +1,7 @@
+import type { LanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Analyzers/Syntax/LanguageSyntax';
+
+export class ShellScriptSyntax implements LanguageSyntax {
+  public readonly commentDelimiters = ['#'];
+
+  public readonly commonCodeParts = ['(', ')', 'else', 'fi', 'done'];
+}

src/application/Parser/Executable/Script/Validation/Analyzers/Syntax/SyntaxFactory.ts

@@ -0,0 +1,19 @@
+import { ScriptingLanguage } from '@/domain/ScriptingLanguage';
+import type { LanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Analyzers/Syntax/LanguageSyntax';
+import { BatchFileSyntax } from './BatchFileSyntax';
+import { ShellScriptSyntax } from './ShellScriptSyntax';
+
+export interface SyntaxFactory {
+  (language: ScriptingLanguage): LanguageSyntax;
+}
+
+export const createSyntax: SyntaxFactory = (language: ScriptingLanguage): LanguageSyntax => {
+  switch (language) {
+    case ScriptingLanguage.batchfile:
+      return new BatchFileSyntax();
+    case ScriptingLanguage.shellscript:
+      return new ShellScriptSyntax();
+    default:
+      throw new RangeError(`Invalid language: "${ScriptingLanguage[language]}"`);
+  }
+};

src/application/Parser/Executable/Script/Validation/CodeValidationRule.ts

@@ -0,0 +1,5 @@
+export enum CodeValidationRule {
+  NoEmptyLines,
+  NoDuplicatedLines,
+  NoTooLongLines,
+}

src/application/Parser/Executable/Script/Validation/CodeValidator.ts

@@ -1,46 +1,78 @@
 import { splitTextIntoLines } from '@/application/Common/Text/SplitTextIntoLines';
-import type { ICodeLine } from './ICodeLine';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
-import type { ICodeValidationRule, IInvalidCodeLine } from './ICodeValidationRule';
+import { createValidationAnalyzers, type ValidationRuleAnalyzerFactory } from './ValidationRuleAnalyzerFactory';
-import type { ICodeValidator } from './ICodeValidator';
+import type { CodeLine, InvalidCodeLine } from './Analyzers/CodeValidationAnalyzer';
+import type { CodeValidationRule } from './CodeValidationRule';
 
-export class CodeValidator implements ICodeValidator {
+export interface CodeValidator {
-  public static readonly instance: ICodeValidator = new CodeValidator();
+  (
-
-  public throwIfInvalid(
     code: string,
-    rules: readonly ICodeValidationRule[],
+    language: ScriptingLanguage,
-  ): void {
+    rules: readonly CodeValidationRule[],
-    if (rules.length === 0) { throw new Error('missing rules'); }
+    analyzerFactory?: ValidationRuleAnalyzerFactory,
-    if (!code) {
+  ): void;
-      return;
-    }
-    const lines = extractLines(code);
-    const invalidLines = rules.flatMap((rule) => rule.analyze(lines));
-    if (invalidLines.length === 0) {
-      return;
-    }
-    const errorText = `Errors with the code.\n${printLines(lines, invalidLines)}`;
-    throw new Error(errorText);
-  }
 }
 
-function extractLines(code: string): ICodeLine[] {
+export const validateCode: CodeValidator = (
+  code,
+  language,
+  rules,
+  analyzerFactory = createValidationAnalyzers,
+) => {
+  const analyzers = analyzerFactory(rules);
+  if (!code) {
+    return;
+  }
+  const lines = extractLines(code);
+  const invalidLines = analyzers.flatMap((analyze) => analyze(lines, language));
+  if (invalidLines.length === 0) {
+    return;
+  }
+  const errorText = `Errors with the code.\n${formatLines(lines, invalidLines)}`;
+  throw new Error(errorText);
+};
+
+function extractLines(code: string): CodeLine[] {
   const lines = splitTextIntoLines(code);
-  return lines.map((lineText, lineIndex): ICodeLine => ({
+  return lines.map((lineText, lineIndex): CodeLine => ({
-    index: lineIndex + 1,
+    lineNumber: lineIndex + 1,
     text: lineText,
   }));
 }
 
-function printLines(
+function formatLines(
-  lines: readonly ICodeLine[],
+  lines: readonly CodeLine[],
-  invalidLines: readonly IInvalidCodeLine[],
+  invalidLines: readonly InvalidCodeLine[],
 ): string {
   return lines.map((line) => {
-    const badLine = invalidLines.find((invalidLine) => invalidLine.index === line.index);
+    const badLine = invalidLines.find((invalidLine) => invalidLine.lineNumber === line.lineNumber);
-    if (!badLine) {
+    return formatLine({
-      return `[${line.index}] ✅ ${line.text}`;
+      lineNumber: line.lineNumber,
-    }
+      text: line.text,
-    return `[${badLine.index}] ❌ ${line.text}\n\t⟶ ${badLine.error}`;
+      error: badLine?.error,
+    });
   }).join('\n');
 }
+function formatLine(
+  line: {
+    readonly lineNumber: number;
+    readonly text: string;
+    readonly error?: string;
+  },
+): string {
+  let text = `[${line.lineNumber}] `;
+  text += line.error ? '❌' : '✅';
+  text += ` ${trimLine(line.text)}`;
+  if (line.error) {
+    text += `\n\t⟶ ${line.error}`;
+  }
+  return text;
+}
+
+function trimLine(line: string) {
+  const maxLength = 500;
+  if (line.length > maxLength) {
+    line = `${line.substring(0, maxLength)}... [Rest of the line trimmed]`;
+  }
+  return line;
+}

src/application/Parser/Executable/Script/Validation/ICodeLine.ts

@@ -1,4 +0,0 @@
-export interface ICodeLine {
-  readonly index: number;
-  readonly text: string;
-}

src/application/Parser/Executable/Script/Validation/ICodeValidationRule.ts

@@ -1,10 +0,0 @@
-import type { ICodeLine } from './ICodeLine';
-
-export interface IInvalidCodeLine {
-  readonly index: number;
-  readonly error: string;
-}
-
-export interface ICodeValidationRule {
-  analyze(lines: readonly ICodeLine[]): IInvalidCodeLine[];
-}

src/application/Parser/Executable/Script/Validation/ICodeValidator.ts

@@ -1,8 +0,0 @@
-import type { ICodeValidationRule } from './ICodeValidationRule';
-
-export interface ICodeValidator {
-  throwIfInvalid(
-    code: string,
-    rules: readonly ICodeValidationRule[],
-  ): void;
-}

src/application/Parser/Executable/Script/Validation/Rules/NoDuplicatedLines.ts

@@ -1,45 +0,0 @@
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
-import type { ICodeLine } from '../ICodeLine';
-import type { ICodeValidationRule, IInvalidCodeLine } from '../ICodeValidationRule';
-
-export class NoDuplicatedLines implements ICodeValidationRule {
-  constructor(private readonly syntax: ILanguageSyntax) { }
-
-  public analyze(lines: readonly ICodeLine[]): IInvalidCodeLine[] {
-    return lines
-      .map((line): IDuplicateAnalyzedLine => ({
-        index: line.index,
-        isIgnored: shouldIgnoreLine(line.text, this.syntax),
-        occurrenceIndices: lines
-          .filter((other) => other.text === line.text)
-          .map((duplicatedLine) => duplicatedLine.index),
-      }))
-      .filter((line) => hasInvalidDuplicates(line))
-      .map((line): IInvalidCodeLine => ({
-        index: line.index,
-        error: `Line is duplicated at line numbers ${line.occurrenceIndices.join(',')}.`,
-      }));
-  }
-}
-
-interface IDuplicateAnalyzedLine {
-  readonly index: number;
-  readonly occurrenceIndices: readonly number[];
-  readonly isIgnored: boolean;
-}
-
-function hasInvalidDuplicates(line: IDuplicateAnalyzedLine): boolean {
-  return !line.isIgnored && line.occurrenceIndices.length > 1;
-}
-
-function shouldIgnoreLine(codeLine: string, syntax: ILanguageSyntax): boolean {
-  const lowerCaseCodeLine = codeLine.toLowerCase();
-  const isCommentLine = () => syntax.commentDelimiters.some(
-    (delimiter) => lowerCaseCodeLine.startsWith(delimiter),
-  );
-  const consistsOfFrequentCommands = () => {
-    const trimmed = lowerCaseCodeLine.trim().split(' ');
-    return trimmed.every((part) => syntax.commonCodeParts.includes(part));
-  };
-  return isCommentLine() || consistsOfFrequentCommands();
-}

src/application/Parser/Executable/Script/Validation/Rules/NoEmptyLines.ts

@@ -1,21 +0,0 @@
-import type { ICodeValidationRule, IInvalidCodeLine } from '../ICodeValidationRule';
-import type { ICodeLine } from '../ICodeLine';
-
-export class NoEmptyLines implements ICodeValidationRule {
-  public analyze(lines: readonly ICodeLine[]): IInvalidCodeLine[] {
-    return lines
-      .filter((line) => (line.text?.trim().length ?? 0) === 0)
-      .map((line): IInvalidCodeLine => ({
-        index: line.index,
-        error: (() => {
-          if (!line.text) {
-            return 'Empty line';
-          }
-          const markedText = line.text
-            .replaceAll(' ', '{whitespace}')
-            .replaceAll('\t', '{tab}');
-          return `Empty line: "${markedText}"`;
-        })(),
-      }));
-  }
-}

src/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax.ts

@@ -1,4 +0,0 @@
-export interface ILanguageSyntax {
-  readonly commentDelimiters: string[];
-  readonly commonCodeParts: string[];
-}

src/application/Parser/Executable/Script/Validation/Syntax/ISyntaxFactory.ts

@@ -1,4 +0,0 @@
-import type { IScriptingLanguageFactory } from '@/application/Common/ScriptingLanguage/IScriptingLanguageFactory';
-import type { ILanguageSyntax } from './ILanguageSyntax';
-
-export type ISyntaxFactory = IScriptingLanguageFactory<ILanguageSyntax>;

src/application/Parser/Executable/Script/Validation/Syntax/ShellScriptSyntax.ts

@@ -1,7 +0,0 @@
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
-
-export class ShellScriptSyntax implements ILanguageSyntax {
-  public readonly commentDelimiters = ['#'];
-
-  public readonly commonCodeParts = ['(', ')', 'else', 'fi', 'done'];
-}

src/application/Parser/Executable/Script/Validation/Syntax/SyntaxFactory.ts

@@ -1,16 +0,0 @@
-import { ScriptingLanguage } from '@/domain/ScriptingLanguage';
-import { ScriptingLanguageFactory } from '@/application/Common/ScriptingLanguage/ScriptingLanguageFactory';
-import type { ILanguageSyntax } from '@/application/Parser/Executable/Script/Validation/Syntax/ILanguageSyntax';
-import { BatchFileSyntax } from './BatchFileSyntax';
-import { ShellScriptSyntax } from './ShellScriptSyntax';
-import type { ISyntaxFactory } from './ISyntaxFactory';
-
-export class SyntaxFactory
-  extends ScriptingLanguageFactory<ILanguageSyntax>
-  implements ISyntaxFactory {
-  constructor() {
-    super();
-    this.registerGetter(ScriptingLanguage.batchfile, () => new BatchFileSyntax());
-    this.registerGetter(ScriptingLanguage.shellscript, () => new ShellScriptSyntax());
-  }
-}

src/application/Parser/Executable/Script/Validation/ValidationRuleAnalyzerFactory.ts

@@ -0,0 +1,47 @@
+import { CodeValidationRule } from './CodeValidationRule';
+import { analyzeDuplicateLines } from './Analyzers/AnalyzeDuplicateLines';
+import { analyzeEmptyLines } from './Analyzers/AnalyzeEmptyLines';
+import { analyzeTooLongLines } from './Analyzers/AnalyzeTooLongLines';
+import type { CodeValidationAnalyzer } from './Analyzers/CodeValidationAnalyzer';
+
+export interface ValidationRuleAnalyzerFactory {
+  (
+    rules: readonly CodeValidationRule[],
+  ): CodeValidationAnalyzer[];
+}
+
+export const createValidationAnalyzers: ValidationRuleAnalyzerFactory = (
+  rules,
+): CodeValidationAnalyzer[] => {
+  if (rules.length === 0) { throw new Error('missing rules'); }
+  validateUniqueRules(rules);
+  return rules.map((rule) => createValidationRule(rule));
+};
+
+function createValidationRule(rule: CodeValidationRule): CodeValidationAnalyzer {
+  switch (rule) {
+    case CodeValidationRule.NoEmptyLines:
+      return analyzeEmptyLines;
+    case CodeValidationRule.NoDuplicatedLines:
+      return analyzeDuplicateLines;
+    case CodeValidationRule.NoTooLongLines:
+      return analyzeTooLongLines;
+    default:
+      throw new Error(`Unknown rule: ${rule}`);
+  }
+}
+
+function validateUniqueRules(
+  rules: readonly CodeValidationRule[],
+): void {
+  const ruleCounts = new Map<CodeValidationRule, number>();
+  rules.forEach((rule) => {
+    ruleCounts.set(rule, (ruleCounts.get(rule) || 0) + 1);
+  });
+  const duplicates = Array.from(ruleCounts.entries())
+    .filter(([, count]) => count > 1)
+    .map(([rule, count]) => `${CodeValidationRule[rule]} (${count} times)`);
+  if (duplicates.length > 0) {
+    throw new Error(`Duplicate rules are not allowed. Duplicates found: ${duplicates.join(', ')}`);
+  }
+}

src/domain/Collection/Validation/CompositeCategoryCollectionValidator.ts

@@ -10,7 +10,7 @@ export type CompositeCategoryCollectionValidator = CategoryCollectionValidator &
       ...Parameters<CategoryCollectionValidator>,
       (readonly CategoryCollectionValidator[])?,
     ]
-  ): void;
+  ): ReturnType<CategoryCollectionValidator>;
 };
 
 export const validateCategoryCollection: CompositeCategoryCollectionValidator = (

src/infrastructure/CodeRunner/Creation/Directory/ScriptDirectoryProvider.ts

@@ -1,23 +0,0 @@
-import type { CodeRunError } from '@/application/CodeRunner/CodeRunner';
-
-export interface ScriptDirectoryProvider {
-  provideScriptDirectory(): Promise<ScriptDirectoryOutcome>;
-}
-
-export type ScriptDirectoryOutcome = SuccessfulDirectoryCreation | FailedDirectoryCreation;
-
-interface ScriptDirectoryCreationStatus {
-  readonly success: boolean;
-  readonly directoryAbsolutePath?: string;
-  readonly error?: CodeRunError;
-}
-
-interface SuccessfulDirectoryCreation extends ScriptDirectoryCreationStatus {
-  readonly success: true;
-  readonly directoryAbsolutePath: string;
-}
-
-interface FailedDirectoryCreation extends ScriptDirectoryCreationStatus {
-  readonly success: false;
-  readonly error: CodeRunError;
-}

src/infrastructure/CodeRunner/Creation/ScriptFileCreationOrchestrator.ts

@@ -1,21 +1,22 @@
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
 import type { Logger } from '@/application/Common/Log/Logger';
 import type { CodeRunError, CodeRunErrorType } from '@/application/CodeRunner/CodeRunner';
-import { FileReadbackVerificationErrors, type ReadbackFileWriter } from '@/infrastructure/ReadbackFileWriter/ReadbackFileWriter';
+import { FileReadbackVerificationErrors, type ReadbackFileWriter } from '@/infrastructure/FileSystem/ReadbackFileWriter/ReadbackFileWriter';
-import { NodeReadbackFileWriter } from '@/infrastructure/ReadbackFileWriter/NodeReadbackFileWriter';
+import { NodeReadbackFileWriter } from '@/infrastructure/FileSystem/ReadbackFileWriter/NodeReadbackFileWriter';
-import { NodeElectronSystemOperations } from '../System/NodeElectronSystemOperations';
+import { NodeElectronFileSystemOperations } from '@/infrastructure/FileSystem/NodeElectronFileSystemOperations';
+import { PersistentApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/PersistentApplicationDirectoryProvider';
+import type { FileSystemOperations } from '@/infrastructure/FileSystem/FileSystemOperations';
+import type { ApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/ApplicationDirectoryProvider';
 import { TimestampedFilenameGenerator } from './Filename/TimestampedFilenameGenerator';
-import { PersistentDirectoryProvider } from './Directory/PersistentDirectoryProvider';
-import type { SystemOperations } from '../System/SystemOperations';
 import type { FilenameGenerator } from './Filename/FilenameGenerator';
 import type { ScriptFilenameParts, ScriptFileCreator, ScriptFileCreationOutcome } from './ScriptFileCreator';
-import type { ScriptDirectoryProvider } from './Directory/ScriptDirectoryProvider';
 
 export class ScriptFileCreationOrchestrator implements ScriptFileCreator {
   constructor(
-    private readonly system: SystemOperations = new NodeElectronSystemOperations(),
+    private readonly fileSystem: FileSystemOperations = NodeElectronFileSystemOperations,
     private readonly filenameGenerator: FilenameGenerator = new TimestampedFilenameGenerator(),
-    private readonly directoryProvider: ScriptDirectoryProvider = new PersistentDirectoryProvider(),
+    private readonly directoryProvider: ApplicationDirectoryProvider
+    = new PersistentApplicationDirectoryProvider(),
     private readonly fileWriter: ReadbackFileWriter = new NodeReadbackFileWriter(),
     private readonly logger: Logger = ElectronLogger,
   ) { }
@@ -26,9 +27,12 @@ export class ScriptFileCreationOrchestrator implements ScriptFileCreator {
   ): Promise<ScriptFileCreationOutcome> {
     const {
       success: isDirectoryCreated, error: directoryCreationError, directoryAbsolutePath,
-    } = await this.directoryProvider.provideScriptDirectory();
+    } = await this.directoryProvider.provideDirectory('script-runs');
     if (!isDirectoryCreated) {
-      return createFailure(directoryCreationError);
+      return createFailure({
+        type: 'DirectoryCreationError',
+        message: `[${directoryCreationError.type}] ${directoryCreationError.message}`,
+      });
     }
     const {
       success: isFilePathConstructed, error: filePathGenerationError, filePath,
@@ -54,7 +58,7 @@ export class ScriptFileCreationOrchestrator implements ScriptFileCreator {
   ): FilePathConstructionOutcome {
     try {
       const filename = this.filenameGenerator.generateFilename(scriptFilenameParts);
-      const filePath = this.system.location.combinePaths(directoryPath, filename);
+      const filePath = this.fileSystem.combinePaths(directoryPath, filename);
       return { success: true, filePath };
     } catch (error) {
       return {

src/infrastructure/CodeRunner/Execution/CommandDefinition/Runner/PermissionSetter/FileSystemExecutablePermissionSetter.ts

@@ -7,7 +7,7 @@ import type { ExecutablePermissionSetter } from './ExecutablePermissionSetter';
 
 export class FileSystemExecutablePermissionSetter implements ExecutablePermissionSetter {
   constructor(
-    private readonly system: SystemOperations = new NodeElectronSystemOperations(),
+    private readonly system: SystemOperations = NodeElectronSystemOperations,
     private readonly logger: Logger = ElectronLogger,
   ) { }
 

src/infrastructure/CodeRunner/Execution/CommandDefinition/Runner/ShellRunner/LoggingNodeShellCommandRunner.ts

@@ -7,7 +7,7 @@ import type { ShellCommandOutcome, ShellCommandRunner } from './ShellCommandRunn
 export class LoggingNodeShellCommandRunner implements ShellCommandRunner {
   constructor(
     private readonly logger: Logger = ElectronLogger,
-    private readonly systemOps: SystemOperations = new NodeElectronSystemOperations(),
+    private readonly systemOps: SystemOperations = NodeElectronSystemOperations,
   ) {
   }
 

src/infrastructure/CodeRunner/System/NodeElectronSystemOperations.ts

@@ -1,57 +1,13 @@
-import { join } from 'node:path';
-import { chmod, mkdir } from 'node:fs/promises';
 import { exec } from 'node:child_process';
-import { app } from 'electron/main';
+import { NodeElectronFileSystemOperations } from '@/infrastructure/FileSystem/NodeElectronFileSystemOperations';
-import type {
+import type { SystemOperations } from './SystemOperations';
-  CommandOps, FileSystemOps, LocationOps, OperatingSystemOps, SystemOperations,
-} from './SystemOperations';
 
 /**
  * Thin wrapper for Node and Electron APIs.
  */
-export class NodeElectronSystemOperations implements SystemOperations {
+export const NodeElectronSystemOperations: SystemOperations = {
-  public readonly operatingSystem: OperatingSystemOps = {
+  fileSystem: NodeElectronFileSystemOperations,
-    /*
+  command: {
-      This method returns the directory for storing app's configuration files.
-      It appends your app's name to the default appData directory.
-      Conventionally, you should store user data files in this directory.
-      However, avoid writing large files here as some environments might back up this directory
-      to cloud storage, potentially causing issues with file size.
-
-      Based on tests it returns:
-
-      - Windows: `%APPDATA%\privacy.sexy`
-      - Linux: `$HOME/.config/privacy.sexy/runs`
-      - macOS: `$HOME/Library/Application Support/privacy.sexy/runs`
-
-      For more details, refer to the Electron documentation: https://web.archive.org/web/20240104154857/https://www.electronjs.org/docs/latest/api/app#appgetpathname
-    */
-    getUserDataDirectory: () => {
-      return app.getPath('userData');
-    },
-  };
-
-  public readonly location: LocationOps = {
-    combinePaths: (...pathSegments) => join(...pathSegments),
-  };
-
-  public readonly fileSystem: FileSystemOps = {
-    setFilePermissions: (
-      filePath: string,
-      mode: string | number,
-    ) => chmod(filePath, mode),
-    createDirectory: async (
-      directoryPath: string,
-      isRecursive?: boolean,
-    ) => {
-      await mkdir(directoryPath, { recursive: isRecursive });
-      // Ignoring the return value from `mkdir`, which is the first directory created
-      // when `recursive` is true, or empty return value.
-      // See https://github.com/nodejs/node/pull/31530
-    },
-  };
-
-  public readonly command: CommandOps = {
     exec,
-  };
+  },
-}
+};

src/infrastructure/CodeRunner/System/SystemOperations.ts

@@ -1,25 +1,11 @@
+import type { FileSystemOperations } from '@/infrastructure/FileSystem/FileSystemOperations';
 import type { exec } from 'node:child_process';
 
 export interface SystemOperations {
-  readonly operatingSystem: OperatingSystemOps;
+  readonly fileSystem: FileSystemOperations;
-  readonly location: LocationOps;
-  readonly fileSystem: FileSystemOps;
   readonly command: CommandOps;
 }
 
-export interface OperatingSystemOps {
-  getUserDataDirectory(): string;
-}
-
-export interface LocationOps {
-  combinePaths(...pathSegments: string[]): string;
-}
-
 export interface CommandOps {
   exec(command: string): ReturnType<typeof exec>;
 }
-
-export interface FileSystemOps {
-  setFilePermissions(filePath: string, mode: string | number): Promise<void>;
-  createDirectory(directoryPath: string, isRecursive?: boolean): Promise<void>;
-}

src/infrastructure/Dialog/Electron/NodeElectronSaveFileDialog.ts

@@ -5,8 +5,8 @@ import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
 import {
   FileType, type SaveFileError, type SaveFileErrorType, type SaveFileOutcome,
 } from '@/presentation/common/Dialog';
-import { FileReadbackVerificationErrors, type ReadbackFileWriter } from '@/infrastructure/ReadbackFileWriter/ReadbackFileWriter';
+import { FileReadbackVerificationErrors, type ReadbackFileWriter } from '@/infrastructure/FileSystem/ReadbackFileWriter/ReadbackFileWriter';
-import { NodeReadbackFileWriter } from '@/infrastructure/ReadbackFileWriter/NodeReadbackFileWriter';
+import { NodeReadbackFileWriter } from '@/infrastructure/FileSystem/ReadbackFileWriter/NodeReadbackFileWriter';
 import type { ElectronSaveFileDialog } from './ElectronSaveFileDialog';
 
 export class NodeElectronSaveFileDialog implements ElectronSaveFileDialog {

src/infrastructure/FileSystem/Directory/ApplicationDirectoryProvider.ts

@@ -0,0 +1,30 @@
+export interface ApplicationDirectoryProvider {
+  provideDirectory(type: DirectoryType): Promise<DirectoryCreationOutcome>;
+}
+
+export type DirectoryType = 'update-installation-files' | 'script-runs';
+
+export type DirectoryCreationOutcome = SuccessfulDirectoryCreation | FailedDirectoryCreation;
+
+export type DirectoryCreationErrorType = 'PathConstructionError' | 'DirectoryWriteError' | 'UserDataFolderRetrievalError';
+
+export interface DirectoryCreationError {
+  readonly type: DirectoryCreationErrorType;
+  readonly message: string;
+}
+
+interface DirectoryCreationStatus {
+  readonly success: boolean;
+  readonly directoryAbsolutePath?: string;
+  readonly error?: DirectoryCreationError;
+}
+
+interface SuccessfulDirectoryCreation extends DirectoryCreationStatus {
+  readonly success: true;
+  readonly directoryAbsolutePath: string;
+}
+
+interface FailedDirectoryCreation extends DirectoryCreationStatus {
+  readonly success: false;
+  readonly error: DirectoryCreationError;
+}

src/infrastructure/FileSystem/Directory/PersistentApplicationDirectoryProvider.ts

@@ -1,32 +1,37 @@
 import type { Logger } from '@/application/Common/Log/Logger';
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
-import type { CodeRunError, CodeRunErrorType } from '@/application/CodeRunner/CodeRunner';
+import { NodeElectronFileSystemOperations } from '@/infrastructure/FileSystem/NodeElectronFileSystemOperations';
-import { NodeElectronSystemOperations } from '../../System/NodeElectronSystemOperations';
+import type {
-import type { SystemOperations } from '../../System/SystemOperations';
+  DirectoryCreationOutcome, ApplicationDirectoryProvider, DirectoryType,
-import type { ScriptDirectoryOutcome, ScriptDirectoryProvider } from './ScriptDirectoryProvider';
+  DirectoryCreationError, DirectoryCreationErrorType,
+} from './ApplicationDirectoryProvider';
+import type { FileSystemOperations } from '../FileSystemOperations';
 
-export const ExecutionSubdirectory = 'runs';
+export const SubdirectoryNames: Record<DirectoryType, string> = {
+  'script-runs': 'runs',
+  'update-installation-files': 'updates',
+};
 
 /**
- * Provides a dedicated directory for script execution.
+ * Provides persistent directories.
  * Benefits of using a persistent directory:
  * - Antivirus Exclusions: Easier antivirus configuration.
  * - Auditability: Stores script execution history for troubleshooting.
  * - Reliability: Avoids issues with directory clean-ups during execution,
  *   seen in Windows Pro Azure VMs when stored on Windows temporary directory.
  */
-export class PersistentDirectoryProvider implements ScriptDirectoryProvider {
+export class PersistentApplicationDirectoryProvider implements ApplicationDirectoryProvider {
   constructor(
-    private readonly system: SystemOperations = new NodeElectronSystemOperations(),
+    private readonly fileSystem: FileSystemOperations = NodeElectronFileSystemOperations,
     private readonly logger: Logger = ElectronLogger,
   ) { }
 
-  public async provideScriptDirectory(): Promise<ScriptDirectoryOutcome> {
+  public async provideDirectory(type: DirectoryType): Promise<DirectoryCreationOutcome> {
     const {
       success: isPathConstructed,
       error: pathConstructionError,
       directoryPath,
-    } = this.constructScriptDirectoryPath();
+    } = this.constructScriptDirectoryPath(type);
     if (!isPathConstructed) {
       return {
         success: false,
@@ -52,7 +57,7 @@ export class PersistentDirectoryProvider implements ScriptDirectoryProvider {
   private async createDirectory(directoryPath: string): Promise<DirectoryPathCreationOutcome> {
     try {
       this.logger.info(`Attempting to create script directory at path: ${directoryPath}`);
-      await this.system.fileSystem.createDirectory(directoryPath, true);
+      await this.fileSystem.createDirectory(directoryPath, true);
       this.logger.info(`Script directory successfully created at: ${directoryPath}`);
       return {
         success: true,
@@ -60,17 +65,26 @@ export class PersistentDirectoryProvider implements ScriptDirectoryProvider {
     } catch (error) {
       return {
         success: false,
-        error: this.handleException(error, 'DirectoryCreationError'),
+        error: this.handleError(error, 'DirectoryWriteError'),
       };
     }
   }
 
-  private constructScriptDirectoryPath(): DirectoryPathConstructionOutcome {
+  private constructScriptDirectoryPath(type: DirectoryType): DirectoryPathConstructionOutcome {
+    let parentDirectory: string;
     try {
-      const parentDirectory = this.system.operatingSystem.getUserDataDirectory();
+      parentDirectory = this.fileSystem.getUserDataDirectory();
-      const scriptDirectory = this.system.location.combinePaths(
+    } catch (error) {
+      return {
+        success: false,
+        error: this.handleError(error, 'UserDataFolderRetrievalError'),
+      };
+    }
+    try {
+      const subdirectoryName = SubdirectoryNames[type];
+      const scriptDirectory = this.fileSystem.combinePaths(
         parentDirectory,
-        ExecutionSubdirectory,
+        subdirectoryName,
       );
       return {
         success: true,
@@ -79,15 +93,15 @@ export class PersistentDirectoryProvider implements ScriptDirectoryProvider {
     } catch (error) {
       return {
         success: false,
-        error: this.handleException(error, 'DirectoryCreationError'),
+        error: this.handleError(error, 'PathConstructionError'),
       };
     }
   }
 
-  private handleException(
+  private handleError(
     exception: Error,
-    errorType: CodeRunErrorType,
+    errorType: DirectoryCreationErrorType,
-  ): CodeRunError {
+  ): DirectoryCreationError {
     const errorMessage = 'Error during script directory creation';
     this.logger.error(errorType, errorMessage, exception);
     return {
@@ -99,7 +113,7 @@ export class PersistentDirectoryProvider implements ScriptDirectoryProvider {
 
 type DirectoryPathConstructionOutcome = {
   readonly success: false;
-  readonly error: CodeRunError;
+  readonly error: DirectoryCreationError;
   readonly directoryPath?: undefined;
 } | {
   readonly success: true;
@@ -109,7 +123,7 @@ type DirectoryPathConstructionOutcome = {
 
 type DirectoryPathCreationOutcome = {
   readonly success: false;
-  readonly error: CodeRunError;
+  readonly error: DirectoryCreationError;
 } | {
   readonly success: true;
   readonly error?: undefined;

src/infrastructure/FileSystem/FileSystemOperations.ts

@@ -0,0 +1,20 @@
+export interface FileSystemOperations {
+  getUserDataDirectory(): string;
+
+  setFilePermissions(filePath: string, mode: string | number): Promise<void>;
+  createDirectory(directoryPath: string, isRecursive?: boolean): Promise<void>;
+
+  isFileAvailable(filePath: string): Promise<boolean>;
+  isDirectoryAvailable(filePath: string): Promise<boolean>;
+  deletePath(filePath: string): Promise<void>;
+  listDirectoryContents(directoryPath: string): Promise<string[]>;
+
+  combinePaths(...pathSegments: string[]): string;
+
+  readFile: (filePath: string, encoding: NodeJS.BufferEncoding) => Promise<string>;
+  writeFile: (
+    filePath: string,
+    fileContents: string,
+    encoding: NodeJS.BufferEncoding,
+  ) => Promise<void>;
+}

src/infrastructure/FileSystem/NodeElectronFileSystemOperations.ts

@@ -0,0 +1,68 @@
+import { join } from 'node:path';
+import {
+  chmod, mkdir,
+  readdir, rm, stat,
+  readFile, writeFile,
+} from 'node:fs/promises';
+import { app } from 'electron/main';
+import type { FileSystemOperations } from './FileSystemOperations';
+import type { Stats } from 'node:original-fs';
+
+/**
+ * Thin wrapper for Node and Electron APIs.
+ */
+export const NodeElectronFileSystemOperations: FileSystemOperations = {
+  combinePaths: (...pathSegments) => join(...pathSegments),
+  setFilePermissions: (
+    filePath: string,
+    mode: string | number,
+  ) => chmod(filePath, mode),
+  createDirectory: async (
+    directoryPath: string,
+    isRecursive?: boolean,
+  ) => {
+    await mkdir(directoryPath, { recursive: isRecursive });
+    // Ignoring the return value from `mkdir`, which is the first directory created
+    // when `recursive` is true, or empty return value.
+    // See https://github.com/nodejs/node/pull/31530
+  },
+  isFileAvailable: async (path) => isPathAvailable(path, (stats) => stats.isFile()),
+  isDirectoryAvailable: async (path) => isPathAvailable(path, (stats) => stats.isDirectory()),
+  deletePath: (path) => rm(path, { recursive: true, force: true }),
+  listDirectoryContents: (directoryPath) => readdir(directoryPath),
+  getUserDataDirectory: () => {
+    /*
+      This method returns the directory for storing app's configuration files.
+      It appends your app's name to the default appData directory.
+      Conventionally, you should store user data files in this directory.
+      However, avoid writing large files here as some environments might back up this directory
+      to cloud storage, potentially causing issues with file size.
+
+      Based on tests it returns:
+
+      - Windows: `%APPDATA%\privacy.sexy`
+      - Linux: `$HOME/.config/privacy.sexy/runs`
+      - macOS: `$HOME/Library/Application Support/privacy.sexy/runs`
+
+      For more details, refer to the Electron documentation: https://web.archive.org/web/20240104154857/https://www.electronjs.org/docs/latest/api/app#appgetpathname
+    */
+    return app.getPath('userData');
+  },
+  writeFile,
+  readFile,
+};
+
+async function isPathAvailable(
+  path: string,
+  condition: (stats: Stats) => boolean,
+): Promise<boolean> {
+  try {
+    const stats = await stat(path);
+    return condition(stats);
+  } catch (error) {
+    if (error.code === 'ENOENT') {
+      return false; // path does not exist
+    }
+    throw error;
+  }
+}

src/infrastructure/FileSystem/ReadbackFileWriter/NodeReadbackFileWriter.ts

@@ -1,22 +1,18 @@
-import { writeFile, access, readFile } from 'node:fs/promises';
-import { constants } from 'node:fs';
 import type { Logger } from '@/application/Common/Log/Logger';
-import { ElectronLogger } from '../Log/ElectronLogger';
+import { ElectronLogger } from '../../Log/ElectronLogger';
+import { NodeElectronFileSystemOperations } from '../NodeElectronFileSystemOperations';
 import type {
   FailedFileWrite, ReadbackFileWriter, FileWriteErrorType,
   FileWriteOutcome, SuccessfulFileWrite,
 } from './ReadbackFileWriter';
+import type { FileSystemOperations } from '../FileSystemOperations';
 
 const FILE_ENCODING: NodeJS.BufferEncoding = 'utf-8';
 
 export class NodeReadbackFileWriter implements ReadbackFileWriter {
   constructor(
     private readonly logger: Logger = ElectronLogger,
-    private readonly fileSystem: FileReadWriteOperations = {
+    private readonly fileSystem: FileSystemOperations = NodeElectronFileSystemOperations,
-      writeFile,
-      readFile: (path, encoding) => readFile(path, encoding),
-      access,
-    },
   ) { }
 
   public async writeAndVerifyFile(
@@ -55,7 +51,9 @@ export class NodeReadbackFileWriter implements ReadbackFileWriter {
     filePath: string,
   ): Promise<FileWriteOutcome> {
     try {
-      await this.fileSystem.access(filePath, constants.F_OK);
+      if (!(await this.fileSystem.isFileAvailable(filePath))) {
+        return this.reportFailure('FileExistenceVerificationFailed', 'File does not exist.');
+      }
       return this.reportSuccess('Verified file existence without reading.');
     } catch (error) {
       return this.reportFailure('FileExistenceVerificationFailed', error);
@@ -107,9 +105,3 @@ export class NodeReadbackFileWriter implements ReadbackFileWriter {
     };
   }
 }
-
-export interface FileReadWriteOperations {
-  readonly writeFile: typeof writeFile;
-  readonly access: typeof access;
-  readFile: (filePath: string, encoding: NodeJS.BufferEncoding) => Promise<string>;
-}

src/infrastructure/RuntimeSanity/Common/FactoryValidator.ts

@@ -1,16 +1,16 @@
-import type { ISanityValidator } from './ISanityValidator';
+import type { SanityValidator } from './SanityValidator';
-import type { ISanityCheckOptions } from './ISanityCheckOptions';
+import type { SanityCheckOptions } from './SanityCheckOptions';
 
 export type FactoryFunction<T> = () => T;
 
-export abstract class FactoryValidator<T> implements ISanityValidator {
+export abstract class FactoryValidator<T> implements SanityValidator {
   private readonly factory: FactoryFunction<T>;
 
   protected constructor(factory: FactoryFunction<T>) {
     this.factory = factory;
   }
 
-  public abstract shouldValidate(options: ISanityCheckOptions): boolean;
+  public abstract shouldValidate(options: SanityCheckOptions): boolean;
 
   public abstract name: string;
 

src/infrastructure/RuntimeSanity/Common/ISanityValidator.ts

@@ -1,7 +0,0 @@
-import type { ISanityCheckOptions } from './ISanityCheckOptions';
-
-export interface ISanityValidator {
-  readonly name: string;
-  shouldValidate(options: ISanityCheckOptions): boolean;
-  collectErrors(): Iterable<string>;
-}

src/infrastructure/RuntimeSanity/Common/SanityCheckOptions.ts

@@ -1,4 +1,4 @@
-export interface ISanityCheckOptions {
+export interface SanityCheckOptions {
   readonly validateEnvironmentVariables: boolean;
   readonly validateWindowVariables: boolean;
 }

src/infrastructure/RuntimeSanity/Common/SanityValidator.ts

@@ -0,0 +1,7 @@
+import type { SanityCheckOptions } from './SanityCheckOptions';
+
+export interface SanityValidator {
+  readonly name: string;
+  shouldValidate(options: SanityCheckOptions): boolean;
+  collectErrors(): Iterable<string>;
+}

src/infrastructure/RuntimeSanity/SanityChecks.ts

@@ -1,16 +1,23 @@
 import { EnvironmentVariablesValidator } from './Validators/EnvironmentVariablesValidator';
-import type { ISanityCheckOptions } from './Common/ISanityCheckOptions';
+import type { SanityCheckOptions } from './Common/SanityCheckOptions';
-import type { ISanityValidator } from './Common/ISanityValidator';
+import type { SanityValidator } from './Common/SanityValidator';
 
-const DefaultSanityValidators: ISanityValidator[] = [
+const DefaultSanityValidators: SanityValidator[] = [
   new EnvironmentVariablesValidator(),
 ];
 
+export interface RuntimeSanityValidator {
+  (
+    options: SanityCheckOptions,
+    validators?: readonly SanityValidator[],
+  ): void;
+}
+
 /* Helps to fail-fast on errors */
-export function validateRuntimeSanity(
+export const validateRuntimeSanity: RuntimeSanityValidator = (
-  options: ISanityCheckOptions,
+  options: SanityCheckOptions,
-  validators: readonly ISanityValidator[] = DefaultSanityValidators,
+  validators: readonly SanityValidator[] = DefaultSanityValidators,
-): void {
+) => {
   if (!validators.length) {
     throw new Error('missing validators');
   }
@@ -26,9 +33,9 @@ export function validateRuntimeSanity(
   if (errorMessages.length > 0) {
     throw new Error(`Sanity check failed.\n${errorMessages.join('\n---\n')}`);
   }
-}
+};
 
-function getErrorMessage(validator: ISanityValidator): string | undefined {
+function getErrorMessage(validator: SanityValidator): string | undefined {
   const errorMessages = [...validator.collectErrors()];
   if (!errorMessages.length) {
     return undefined;

src/infrastructure/RuntimeSanity/Validators/EnvironmentVariablesValidator.ts

@@ -1,7 +1,7 @@
 import type { IEnvironmentVariables } from '@/infrastructure/EnvironmentVariables/IEnvironmentVariables';
 import { EnvironmentVariablesFactory } from '@/infrastructure/EnvironmentVariables/EnvironmentVariablesFactory';
 import { FactoryValidator, type FactoryFunction } from '../Common/FactoryValidator';
-import type { ISanityCheckOptions } from '../Common/ISanityCheckOptions';
+import type { SanityCheckOptions } from '../Common/SanityCheckOptions';
 
 export class EnvironmentVariablesValidator extends FactoryValidator<IEnvironmentVariables> {
   constructor(
@@ -14,7 +14,7 @@ export class EnvironmentVariablesValidator extends FactoryValidator<IEnvironment
 
   public override name = 'environment variables';
 
-  public override shouldValidate(options: ISanityCheckOptions): boolean {
+  public override shouldValidate(options: SanityCheckOptions): boolean {
     return options.validateEnvironmentVariables;
   }
 }

src/infrastructure/RuntimeSanity/Validators/WindowVariablesValidator.ts

@@ -1,6 +1,6 @@
 import type { WindowVariables } from '@/infrastructure/WindowVariables/WindowVariables';
 import { FactoryValidator, type FactoryFunction } from '../Common/FactoryValidator';
-import type { ISanityCheckOptions } from '../Common/ISanityCheckOptions';
+import type { SanityCheckOptions } from '../Common/SanityCheckOptions';
 
 export class WindowVariablesValidator extends FactoryValidator<WindowVariables> {
   constructor(factory: FactoryFunction<WindowVariables> = () => window) {
@@ -9,7 +9,7 @@ export class WindowVariablesValidator extends FactoryValidator<WindowVariables>
 
   public override name = 'window variables';
 
-  public override shouldValidate(options: ISanityCheckOptions): boolean {
+  public override shouldValidate(options: SanityCheckOptions): boolean {
     return options.validateWindowVariables;
   }
 }

src/infrastructure/ScriptDiagnostics/ScriptEnvironmentDiagnosticsCollector.ts

@@ -1,19 +1,22 @@
 import type { ScriptDiagnosticData, ScriptDiagnosticsCollector } from '@/application/ScriptDiagnostics/ScriptDiagnosticsCollector';
 import type { RuntimeEnvironment } from '@/infrastructure/RuntimeEnvironment/RuntimeEnvironment';
 import { CurrentEnvironment } from '@/infrastructure/RuntimeEnvironment/RuntimeEnvironmentFactory';
-import { PersistentDirectoryProvider } from '@/infrastructure/CodeRunner/Creation/Directory/PersistentDirectoryProvider';
+import type { ApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/ApplicationDirectoryProvider';
-import type { ScriptDirectoryProvider } from '../CodeRunner/Creation/Directory/ScriptDirectoryProvider';
+import { PersistentApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/PersistentApplicationDirectoryProvider';
 
 export class ScriptEnvironmentDiagnosticsCollector implements ScriptDiagnosticsCollector {
   constructor(
-    private readonly directoryProvider: ScriptDirectoryProvider = new PersistentDirectoryProvider(),
+    private readonly directoryProvider: ApplicationDirectoryProvider
+    = new PersistentApplicationDirectoryProvider(),
     private readonly environment: RuntimeEnvironment = CurrentEnvironment,
   ) { }
 
   public async collectDiagnosticInformation(): Promise<ScriptDiagnosticData> {
-    const { directoryAbsolutePath } = await this.directoryProvider.provideScriptDirectory();
+    const {
+      directoryAbsolutePath: scriptsDirectory,
+    } = await this.directoryProvider.provideDirectory('script-runs');
     return {
-      scriptsDirectoryAbsolutePath: directoryAbsolutePath,
+      scriptsDirectoryAbsolutePath: scriptsDirectory,
       currentOperatingSystem: this.environment.os,
     };
   }

src/presentation/assets/styles/_colors.scss

@@ -6,19 +6,20 @@
         - Darker than default: Shades are named as `color-{name}-dark`, `color-{name}-darker`, or `color-{name}-darkest`.
         - Lighter than default: Tints are named as `color-{name}-light`, `color-{name}-lighter`, or `color-{name}-lightest`.
 */
+@use 'sass:color';
 
 // --- Primary | The color displayed most frequently across screens and components
 $color-primary              : #3a65ab;
-$color-primary-light        : lighten($color-primary, 30%);
+$color-primary-light        : color.adjust($color-primary, $lightness: 30%);
-$color-primary-dark         : darken($color-primary, 18%);
+$color-primary-dark         : color.adjust($color-primary, $lightness: -18%);
-$color-primary-darker       : darken($color-primary, 32%);
+$color-primary-darker       : color.adjust($color-primary, $lightness: -32%);
-$color-primary-darkest      : darken($color-primary, 44%);
+$color-primary-darkest      : color.adjust($color-primary, $lightness: -44%);
 // Text/iconography color that is usable on top of primary color
 $color-on-primary           : #e4f1fe;
 
 // --- Secondary | Accent color, should be applied sparingly to accent select parts of UI
 $color-secondary            : #00D1AD;
-$color-secondary-light      : lighten($color-secondary, 48%);
+$color-secondary-light      : color.adjust($color-secondary, $lightness: 48%);
 // Text/iconography color that is usable on top of secondary color
 $color-on-secondary         : #005051;
 

src/presentation/assets/styles/base/_index.scss

@@ -53,3 +53,17 @@ sup {
   vertical-align: super;
   font-size: $font-size-relative-smallest;
 }
+
+kbd {
+  font-family: unset; // Reset the default browser styles
+  background-color: $color-primary-dark;
+  border: 1px solid $color-primary-darker;
+  border-radius: 0.2em;
+  box-shadow: inset 0 1px 0 0 $color-primary-dark, inset 0 -2px 0 0 $color-primary-darker;
+  font-family: $font-family-monospace;
+  font-size: $font-size-relative-smallest;
+  padding: $spacing-relative-x-small $spacing-relative-x-small;
+  text-align: center;
+  user-select: none;
+  white-space: nowrap;
+}

src/presentation/bootstrapping/ApplicationBootstrapper.ts

@@ -1,4 +1,4 @@
-import { RuntimeSanityValidator } from './Modules/RuntimeSanityValidator';
+import { RuntimeSanityBootstrapper } from './Modules/RuntimeSanityBootstrapper';
 import { AppInitializationLogger } from './Modules/AppInitializationLogger';
 import { DependencyBootstrapper } from './Modules/DependencyBootstrapper';
 import { MobileSafariActivePseudoClassEnabler } from './Modules/MobileSafariActivePseudoClassEnabler';
@@ -17,7 +17,7 @@ export class ApplicationBootstrapper implements Bootstrapper {
 
   private static getAllBootstrappers(): Bootstrapper[] {
     return [
-      new RuntimeSanityValidator(),
+      new RuntimeSanityBootstrapper(),
       new DependencyBootstrapper(),
       new AppInitializationLogger(),
       new MobileSafariActivePseudoClassEnabler(),

src/presentation/bootstrapping/Modules/RuntimeSanityBootstrapper.ts

@@ -0,0 +1,15 @@
+import { validateRuntimeSanity, type RuntimeSanityValidator } from '@/infrastructure/RuntimeSanity/SanityChecks';
+import type { Bootstrapper } from '../Bootstrapper';
+
+export class RuntimeSanityBootstrapper implements Bootstrapper {
+  constructor(private readonly validator: RuntimeSanityValidator = validateRuntimeSanity) {
+
+  }
+
+  public async bootstrap(): Promise<void> {
+    this.validator({
+      validateEnvironmentVariables: true,
+      validateWindowVariables: true,
+    });
+  }
+}

src/presentation/bootstrapping/Modules/RuntimeSanityValidator.ts

@@ -1,15 +0,0 @@
-import { validateRuntimeSanity } from '@/infrastructure/RuntimeSanity/SanityChecks';
-import type { Bootstrapper } from '../Bootstrapper';
-
-export class RuntimeSanityValidator implements Bootstrapper {
-  constructor(private readonly validator = validateRuntimeSanity) {
-
-  }
-
-  public async bootstrap(): Promise<void> {
-    this.validator({
-      validateEnvironmentVariables: true,
-      validateWindowVariables: true,
-    });
-  }
-}

src/presentation/components/Code/Ace/AceCodeEditorFactory.ts

@@ -0,0 +1,91 @@
+import ace from './ace-importer';
+import type { CodeEditorFactory, SupportedSyntaxLanguage } from '../CodeEditorFactory';
+
+const CodeEditorTheme = 'xcode';
+
+export const initializeAceEditor: CodeEditorFactory = (options) => {
+  const editor = ace.edit(options.editorContainerElementId);
+  const mode = getAceModeName(options.language);
+  editor.getSession().setMode(`ace/mode/${mode}`);
+  editor.setTheme(`ace/theme/${CodeEditorTheme}`);
+  editor.setReadOnly(true);
+  editor.setAutoScrollEditorIntoView(true);
+  editor.setShowPrintMargin(false); // Hide the vertical line
+  editor.getSession().setUseWrapMode(true); // Make code readable on mobile
+  hideActiveLineAndCursorUntilInteraction(editor);
+  return {
+    setContent: (content) => editor.setValue(content, 1),
+    destroy: () => editor.destroy(),
+    scrollToLine: (lineNumber) => {
+      const column = editor.session.getLine(lineNumber).length;
+      if (column === undefined) {
+        return;
+      }
+      editor.gotoLine(lineNumber, column, true);
+    },
+    updateSize: () => editor?.resize(),
+    applyStyleToLineRange: (start, end, className) => {
+      const AceRange = ace.require('ace/range').Range;
+      const markerId = editor.session.addMarker(
+        new AceRange(start, 0, end, 0),
+        className,
+        'fullLine',
+      );
+      return {
+        clearStyle: () => {
+          editor.session.removeMarker(markerId);
+        },
+      };
+    },
+  };
+};
+
+function getAceModeName(language: SupportedSyntaxLanguage): string {
+  switch (language) {
+    case 'batchfile': return 'batchfile';
+    case 'shellscript': return 'sh';
+    default:
+      throw new Error(`Language not supported: ${language}`);
+  }
+}
+
+function hideActiveLineAndCursorUntilInteraction(editor: ace.Ace.Editor) {
+  hideActiveLineAndCursor(editor);
+  editor.session.on('change', () => {
+    editor.session.selection.clearSelection();
+    hideActiveLineAndCursor(editor);
+  });
+  editor.session.selection.on('changeSelection', () => {
+    showActiveLineAndCursor(editor);
+  });
+}
+
+function hideActiveLineAndCursor(editor: ace.Ace.Editor): void {
+  editor.setHighlightGutterLine(false); // Remove highlighting on line number column
+  editor.setHighlightActiveLine(false); // Remove highlighting throughout the line
+  setCursorVisibility(false, editor);
+}
+
+function showActiveLineAndCursor(editor: ace.Ace.Editor): void {
+  editor.setHighlightGutterLine(true); // Show highlighting on line number column
+  editor.setHighlightActiveLine(true); // Show highlighting throughout the line
+  setCursorVisibility(true, editor);
+}
+
+// Shows/removes vertical line after focused character
+function setCursorVisibility(
+  isVisible: boolean,
+  editor: ace.Ace.Editor,
+) {
+  const cursor = editor.renderer.container.querySelector('.ace_cursor-layer') as HTMLElement;
+  if (!cursor) {
+    throw new Error('Cannot find Ace cursor, did Ace change its rendering?');
+  }
+  cursor.style.display = isVisible ? '' : 'none';
+  // Implementation options for cursor visibility:
+  //   ❌ editor.renderer.showCursor() and hideCursor(): Not functioning as expected
+  //   ❌ editor.renderer.#cursorLayer: No longer part of the public API
+  //   ✅ .ace_hidden-cursors { opacity: 0; }: Hides cursor when not focused
+  //      Pros: Works more automatically
+  //      Cons: Provides less control over visibility toggling
+}

src/presentation/components/Code/Ace/ace-importer.ts

@@ -5,7 +5,6 @@ import ace from 'ace-builds';
   when built with Vite (`npm run build`).
 */
 
-import 'ace-builds/src-noconflict/theme-github';
 import 'ace-builds/src-noconflict/theme-xcode';
 import 'ace-builds/src-noconflict/mode-batchfile';
 import 'ace-builds/src-noconflict/mode-sh';

src/presentation/components/Code/CodeButtons/Save/BrowserRunInstructions/BrowserRunInstructions.vue

@@ -6,7 +6,7 @@
     <article>
       <h3>1. The Easy Alternative</h3>
       <p>
-        Run your script without any manual steps by
+        Run your script securely without any manual steps by
         <a :href="downloadUrl">downloading desktop version</a> of {{ appName }} on the
         {{ osName }} system you wish to configure, and then click on the Run button. This is
         recommended for most users.
@@ -47,6 +47,8 @@ export default defineComponent({
     },
   },
   setup() {
+    ensureBrowserEnvironment();
+
     const { currentState } = injectKey((keys) => keys.useCollectionState);
 
     const { projectDetails } = injectKey((keys) => keys.useApplication);
@@ -70,6 +72,13 @@ export default defineComponent({
     };
   },
 });
+
+function ensureBrowserEnvironment(): void {
+  const { isRunningAsDesktopApplication } = injectKey((keys) => keys.useRuntimeEnvironment);
+  if (isRunningAsDesktopApplication) {
+    throw new Error('Not applicable in desktop environments');
+  }
+}
 </script>
 
 <style scoped lang="scss">

src/presentation/components/Code/CodeButtons/Save/BrowserRunInstructions/Steps/Platforms/LinuxInstructions.vue

@@ -16,29 +16,29 @@
       Open terminal.
       <InfoTooltipInline>
         <p>
-          Opening terminal changes based on the distro you run.
+          Opening terminal changes based on the distribution you run.
         </p>
         <p>
           You may search for "Terminal" in your application launcher to find it.
         </p>
         <p>
-          Alternatively use terminal shortcut for your distro if it has one by default:
+          Alternatively use terminal shortcut for your distribution if it has one by default:
-          <ul>
-            <li>
-              <code>Ctrl-Alt-T</code>:
-              Ubuntu, CentOS, Linux Mint, Elementary OS, ubermix, Kali…
-            </li>
-            <li>
-              <code>Super-T</code>: Pop!_OS…
-            </li>
-            <li>
-              <code>Alt-T</code>: Parrot OS…
-            </li>
-            <li>
-              <code>Ctrl-Alt-Insert</code>: Bodhi Linux…
-            </li>
-          </ul>
         </p>
+        <ul>
+          <li>
+            <kbd>Ctrl</kbd> + <kbd>Alt</kbd> + <kbd>T</kbd>:
+            Ubuntu, CentOS, Linux Mint, Elementary OS, ubermix, Kali…
+          </li>
+          <li>
+            <kbd>Super</kbd> + <kbd>T</kbd>: Pop!_OS…
+          </li>
+          <li>
+            <kbd>Alt</kbd> + <kbd>T</kbd>: Parrot OS…
+          </li>
+          <li>
+            <kbd>Ctrl</kbd> + <kbd>Alt</kbd> + <kbd>Insert</kbd>: Bodhi Linux…
+          </li>
+        </ul>
       </InfoTooltipInline>
     </InstructionStep>
     <InstructionStep>
@@ -50,19 +50,22 @@
           <CopyableCommand>cd ~/Downloads</CopyableCommand>
           <template #info>
             <p>
-              Press on <code>enter/return</code> key after running the command.
+              Press on <kbd>Enter</kbd> or <kbd>Return</kbd> key after running the command.
             </p>
             <p>
-              If the file is not downloaded on Downloads folder,
+              If you didn't save the file in your <strong>Downloads</strong> folder:
-              change <code>Downloads</code> to path where the file is downloaded.
             </p>
+            <ol>
+              <li>Locate where you saved the file.</li>
+              <li>In the command, replace <code>Downloads</code> with the correct folder path.</li>
+            </ol>
             <p>
               This command means:
-              <ul>
-                <li><code>cd</code> will change the current folder.</li>
-                <li><code>~</code> is the user home directory.</li>
-              </ul>
             </p>
+            <ul>
+              <li><code>cd</code> will change the current folder.</li>
+              <li><code>~</code> is the user home directory.</li>
+            </ul>
           </template>
         </InfoTooltipWrapper>
       </p>
@@ -76,21 +79,23 @@
           <CopyableCommand>chmod +x {{ filename }}</CopyableCommand>
           <template #info>
             <p>
-              Press on <code>enter/return</code> key after running the command.
+              Press on <kbd>Enter</kbd> or <kbd>Return</kbd> key after running the command.
             </p>
             <p>
               It will make the file executable.
             </p>
             <p>
-              If you use desktop environment you can alternatively (instead of running the command):
+              Alternatively, if you're using a graphical desktop environment, you can do this
-              <ol>
+              without the command line:
-                <li>Locate the file using your file manager.</li>
-                <li>Right click on the file, select "Properties".</li>
-                <li>Go to "Permissions" and check "Allow executing file as program".</li>
-              </ol>
             </p>
+            <ol>
+              <li>Locate the file using your file manager.</li>
+              <li>Right click on the file, select <strong>Properties</strong>.</li>
+              <li>Go to <strong>Permissions</strong>.</li>
+              <li>Check <strong>Allow executing file as program</strong>.</li>
+            </ol>
             <p>
-              These GUI steps and name of options may change depending on your file manager.'
+              These GUI steps and name of options may change depending on your file manager.
             </p>
           </template>
         </InfoTooltipWrapper>
@@ -110,7 +115,8 @@
             </p>
             <ol>
               <li>Locate the file using your file manager.</li>
-              <li>Right click on the file, select "Run as program".</li>
+              <li>Right click on the file.</li>
+              <li>Select <strong>Run as program</strong> or similar option.</li>
             </ol>
           </template>
         </InfoTooltipWrapper>
@@ -124,10 +130,10 @@
           registered, so keep typing.
         </p>
         <p>
-          Press on <code>enter/return</code> key after typing your password.
+          Press the <kbd>Enter</kbd> or <kbd>Return</kbd> key after typing your password.
         </p>
         <p>
-          Administrator privileges are required to configure OS.
+          Administrator privileges are required for configurations.
         </p>
       </InfoTooltipInline>
     </InstructionStep>

src/presentation/components/Code/CodeButtons/Save/BrowserRunInstructions/Steps/Platforms/MacOsInstructions.vue

@@ -13,9 +13,28 @@
       </InfoTooltipInline>
     </InstructionStep>
     <InstructionStep>
-      Open terminal.
+      Open your terminal.
       <InfoTooltipInline>
-        Type Terminal into Spotlight or open it from the Applications -> Utilities folder.
+        <p>There are two easy ways to open the default terminal on your Mac:</p>
+        <ol>
+          <li>
+            Using macOS search (<strong>Spotlight</strong>):
+            <ul>
+              <li>Press <kbd>Cmd</kbd> + <kbd>Space</kbd> to open <strong>Spotlight</strong>.</li>
+              <li>
+                Type <strong>Terminal</strong> and press <kbd>Enter</kbd> or <kbd>Return</kbd>.
+              </li>
+            </ul>
+          </li>
+          <li>
+            Using <strong>Finder</strong>:
+            <ul>
+              <li>Open <strong>Finder</strong>.</li>
+              <li>Go to <strong>Applications</strong> → <strong>Utilities</strong>.</li>
+              <li>Double-click on <strong>Terminal</strong>.</li>
+            </ul>
+          </li>
+        </ol>
       </InfoTooltipInline>
     </InstructionStep>
     <InstructionStep>
@@ -27,19 +46,22 @@
           <CopyableCommand>cd ~/Downloads</CopyableCommand>
           <template #info>
             <p>
-              Press on <code>enter/return</code> key after running the command.
+              Press on <kbd>Enter</kbd> or <kbd>Return</kbd> key after running the command.
             </p>
             <p>
-              If the file is not downloaded on Downloads folder,
+              If you didn't save the file in your <strong>Downloads</strong> folder:
-              change <code>Downloads</code> to path where the file is downloaded.
             </p>
+            <ol>
+              <li>Locate where you saved the file.</li>
+              <li>In the command, replace <code>Downloads</code> with the correct folder path.</li>
+            </ol>
             <p>
               This command means:
-              <ul>
-                <li><code>cd</code> will change the current folder.</li>
-                <li><code>~</code> is the user home directory.</li>
-              </ul>
             </p>
+            <ul>
+              <li><code>cd</code> will change the current folder.</li>
+              <li><code>~</code> is the user home directory.</li>
+            </ul>
           </template>
         </InfoTooltipWrapper>
       </p>
@@ -53,7 +75,7 @@
           <CopyableCommand>chmod +x {{ filename }}</CopyableCommand>
           <template #info>
             <p>
-              Press on <code>enter/return</code> key after running the command.
+              Press on <kbd>Enter</kbd> or <kbd>Return</kbd> key after running the command.
             </p>
             <p>
               It will make the file executable.
@@ -83,10 +105,10 @@
           still registered, so keep typing.
         </p>
         <p>
-          Press on <code>enter/return</code> key after typing your password.
+          Press the <kbd>Enter</kbd> or <kbd>Return</kbd> key after typing your password.
         </p>
         <p>
-          Administrator privileges are required to configure OS.
+          Administrator privileges are required for configurations.
         </p>
       </InfoTooltipInline>
     </InstructionStep>

src/presentation/components/Code/CodeButtons/Save/BrowserRunInstructions/Steps/Platforms/WindowsInstructions.vue

@@ -36,7 +36,7 @@
       </InfoTooltipInline>
     </InstructionStep>
     <InstructionStep>
-      If your antivirus (e.g., Defender) alerts you, address the warning.
+      If your antivirus (e.g., <strong>Defender</strong>) alerts you, address the warning.
       <InfoTooltipInline>
         <!--
           Tests (15/01/2023):
@@ -52,7 +52,7 @@
           Don't worry; privacy.sexy is secure, transparent, and open-source.
         </p>
         <p>
-          To handle false warnings in Microsoft Defender:
+          To handle false warnings in <strong>Defender</strong>:
         </p>
         <ol>
           <li>
@@ -103,21 +103,22 @@
       </InfoTooltipInline>
     </InstructionStep>
     <InstructionStep>
-      If prompted, confirm SmartScreen warnings.
+      If prompted, confirm <strong>SmartScreen</strong> warnings.
       <InfoTooltipInline>
         <p>
-          Windows SmartScreen might display a cautionary message.
+          <strong>Defender SmartScreen</strong> may display a cautionary message.
         </p>
         <p>
           This happens since privacy.sexy scripts are not recognized
           by Microsoft's certification process.
         </p>
         <p>
-          <ol>
+          If you see the warning, bypass it by following these steps:
-            <li>Select <strong>More info</strong>.</li>
-            <li>Select <strong>Run anyway</strong>.</li>
-          </ol>
         </p>
+        <ol>
+          <li>Select <strong>More info</strong>.</li>
+          <li>Select <strong>Run anyway</strong>.</li>
+        </ol>
       </InfoTooltipInline>
     </InstructionStep>
     <InstructionStep>

src/presentation/components/Code/CodeButtons/Save/CodeSaveButton.vue

@@ -6,7 +6,7 @@
       @click="saveCode"
     />
     <ModalDialog v-model="areInstructionsVisible">
-      <RunInstructions :filename="filename" />
+      <BrowserRunInstructions :filename="filename" />
     </ModalDialog>
   </div>
 </template>
@@ -23,12 +23,12 @@ import { ScriptFilename } from '@/application/CodeRunner/ScriptFilename';
 import { FileType } from '@/presentation/common/Dialog';
 import IconButton from '../IconButton.vue';
 import { createScriptErrorDialog } from '../ScriptErrorDialog';
-import RunInstructions from './RunInstructions/RunInstructions.vue';
+import BrowserRunInstructions from './BrowserRunInstructions/BrowserRunInstructions.vue';
 
 export default defineComponent({
   components: {
     IconButton,
-    RunInstructions,
+    BrowserRunInstructions,
     ModalDialog,
   },
   setup() {
@@ -55,7 +55,12 @@ export default defineComponent({
         }, scriptDiagnosticsCollector)));
         return;
       }
-      areInstructionsVisible.value = true;
+      if (!isRunningAsDesktopApplication) {
+        areInstructionsVisible.value = true;
+      }
+      // On desktop, it would be better to to prompt the user with a system
+      // dialog offering options after saving, such as:
+      // • Open Containing Folder • "Open File" in default text editor • Close
     }
 
     return {

src/presentation/components/Code/CodeEditorFactory.ts

@@ -0,0 +1,30 @@
+/**
+ * Abstraction layer for code editor functionality.
+ * Allows for flexible integration and easy switching of third-party editor implementations.
+ */
+export interface CodeEditorFactory {
+  (options: CodeEditorOptions): CodeEditor;
+}
+
+export interface CodeEditorOptions {
+  readonly editorContainerElementId: string;
+  readonly language: SupportedSyntaxLanguage;
+}
+
+export type SupportedSyntaxLanguage = 'batchfile' | 'shellscript';
+
+export interface CodeEditor {
+  destroy(): void;
+  setContent(content: string): void;
+  scrollToLine(lineNumber: number): void;
+  updateSize(): void;
+  applyStyleToLineRange(
+    startLineNumber: number,
+    endLineNumber: number,
+    className: string,
+  ): CodeEditorStyleHandle;
+}
+
+export interface CodeEditorStyleHandle {
+  clearStyle(): void;
+}

src/presentation/components/Code/TheCodeArea.vue

@@ -25,7 +25,8 @@ import { CodeBuilderFactory } from '@/application/Context/State/Code/Generation/
 import SizeObserver from '@/presentation/components/Shared/SizeObserver.vue';
 import { NonCollapsing } from '@/presentation/components/Scripts/View/Cards/NonCollapsingDirective';
 import type { ProjectDetails } from '@/domain/Project/ProjectDetails';
-import ace from './ace-importer';
+import { initializeAceEditor } from './Ace/AceCodeEditorFactory';
+import type { SupportedSyntaxLanguage, CodeEditor, CodeEditorStyleHandle } from './CodeEditorFactory';
 
 export default defineComponent({
   components: {
@@ -34,13 +35,7 @@ export default defineComponent({
   directives: {
     NonCollapsing,
   },
-  props: {
+  setup() {
-    theme: {
-      type: String,
-      default: undefined,
-    },
-  },
-  setup(props) {
     const { onStateChange, currentState } = injectKey((keys) => keys.useCollectionState);
     const { projectDetails } = injectKey((keys) => keys.useApplication);
     const { events } = injectKey((keys) => keys.useAutoUnsubscribedEvents);
@@ -48,8 +43,8 @@ export default defineComponent({
     const editorId = 'codeEditor';
     const highlightedRange = ref(0);
 
-    let editor: ace.Ace.Editor | undefined;
+    let editor: CodeEditor | undefined;
-    let currentMarkerId: number | undefined;
+    let currentMarker: CodeEditorStyleHandle | undefined;
 
     onUnmounted(() => {
       destroyEditor();
@@ -63,11 +58,10 @@ export default defineComponent({
 
     function handleNewState(newState: IReadOnlyCategoryCollectionState) {
       destroyEditor();
-      editor = initializeEditor(
+      editor = initializeAceEditor({
-        props.theme,
+        editorContainerElementId: editorId,
-        editorId,
+        language: getLanguage(newState.collection.scripting.language),
-        newState.collection.scripting.language,
+      });
-      );
       const appCode = newState.code;
       updateCode(appCode.current, newState.collection.scripting.language);
       events.unsubscribeAllAndRegister([
@@ -77,7 +71,7 @@ export default defineComponent({
 
     function updateCode(code: string, language: ScriptingLanguage) {
       const innerCode = code || getDefaultCode(language, projectDetails);
-      editor?.setValue(innerCode, 1);
+      editor?.setContent(innerCode);
     }
 
     function handleCodeChange(event: ICodeChangedEvent) {
@@ -91,7 +85,7 @@ export default defineComponent({
     }
 
     function sizeChanged() {
-      editor?.resize();
+      editor?.updateSize();
     }
 
     function destroyEditor() {
@@ -100,11 +94,11 @@ export default defineComponent({
     }
 
     function removeCurrentHighlighting() {
-      if (!currentMarkerId) {
+      if (!currentMarker) {
         return;
       }
-      editor?.session.removeMarker(currentMarkerId);
+      currentMarker?.clearStyle();
-      currentMarkerId = undefined;
+      currentMarker = undefined;
       highlightedRange.value = 0;
     }
 
@@ -117,28 +111,15 @@ export default defineComponent({
       const end = Math.max(
         ...positions.map((position) => position.endLine),
       );
-      scrollToLine(end + 2);
+      editor?.scrollToLine(end + 2);
       highlight(start, end);
     }
 
     function highlight(startRow: number, endRow: number) {
-      const AceRange = ace.require('ace/range').Range;
+      currentMarker = editor?.applyStyleToLineRange(startRow, endRow, 'code-area__highlight');
-      currentMarkerId = editor?.session.addMarker(
-        new AceRange(startRow, 0, endRow, 0),
-        'code-area__highlight',
-        'fullLine',
-      );
       highlightedRange.value = endRow - startRow;
     }
 
-    function scrollToLine(row: number) {
-      const column = editor?.session.getLine(row).length;
-      if (column === undefined) {
-        return;
-      }
-      editor?.gotoLine(row, column, true);
-    }
-
     return {
       editorId,
       highlightedRange,
@@ -147,29 +128,12 @@ export default defineComponent({
   },
 });
 
-function initializeEditor(
+function getLanguage(language: ScriptingLanguage): SupportedSyntaxLanguage {
-  theme: string | undefined,
-  editorId: string,
-  language: ScriptingLanguage,
-): ace.Ace.Editor {
-  theme = theme || 'github';
-  const editor = ace.edit(editorId);
-  const lang = getLanguage(language);
-  editor.getSession().setMode(`ace/mode/${lang}`);
-  editor.setTheme(`ace/theme/${theme}`);
-  editor.setReadOnly(true);
-  editor.setAutoScrollEditorIntoView(true);
-  editor.setShowPrintMargin(false); // hides vertical line
-  editor.getSession().setUseWrapMode(true); // So code is readable on mobile
-  return editor;
-}
-
-function getLanguage(language: ScriptingLanguage) {
   switch (language) {
     case ScriptingLanguage.batchfile: return 'batchfile';
-    case ScriptingLanguage.shellscript: return 'sh';
+    case ScriptingLanguage.shellscript: return 'shellscript';
     default:
-      throw new Error('unknown language');
+      throw new Error(`Unsupported language: ${language}`);
   }
 }
 

src/presentation/components/Scripts/TheScriptArea.vue

@@ -11,7 +11,7 @@
         <TheScriptsView :current-view="currentView" />
       </template>
       <template #second>
-        <TheCodeArea theme="xcode" />
+        <TheCodeArea />
       </template>
     </HorizontalResizeSlider>
   </div>

src/presentation/components/Scripts/View/Tree/TreeView/Node/HierarchicalTreeNode.vue

@@ -39,7 +39,7 @@
           :tree-root="treeRoot"
           :rendering-strategy="renderingStrategy"
         >
-          <template #node-content="slotProps">
+          <template #node-content="slotProps: NodeMetadata">
             <slot name="node-content" v-bind="slotProps" />
           </template>
         </HierarchicalTreeNode>
@@ -55,6 +55,7 @@ import { useCurrentTreeNodes } from '../UseCurrentTreeNodes';
 import { useNodeState } from './UseNodeState';
 import LeafTreeNode from './LeafTreeNode.vue';
 import InteractableNode from './InteractableNode.vue';
+import type { NodeMetadata } from '../../NodeContent/NodeMetadata';
 import type { TreeRoot } from '../TreeRoot/TreeRoot';
 import type { TreeNode, TreeNodeId } from './TreeNode';
 import type { NodeRenderingStrategy } from '../Rendering/Scheduling/NodeRenderingStrategy';
@@ -107,6 +108,7 @@ export default defineComponent({
     );
 
     return {
+      NodeMetadata: Object as PropType<NodeMetadata>,
       renderedNodeIds,
       isExpanded,
       toggleExpand,

src/presentation/components/Scripts/View/Tree/TreeView/TreeRoot/TreeRootManager.ts

@@ -11,11 +11,17 @@ export class TreeRootManager implements TreeRoot {
 
   constructor(
     collection: TreeNodeCollection = new TreeNodeInitializerAndUpdater(),
-    createFocusManager: (
+    createFocusManager: FocusManagerFactory = (
-      collection: TreeNodeCollection
+      nodes,
-    ) => SingleNodeFocusManager = (nodes) => new SingleNodeCollectionFocusManager(nodes),
+    ) => new SingleNodeCollectionFocusManager(nodes),
   ) {
     this.collection = collection;
     this.focus = createFocusManager(this.collection);
   }
 }
+
+export interface FocusManagerFactory {
+  (
+    collection: TreeNodeCollection
+  ): SingleNodeFocusManager;
+}

src/presentation/components/Shared/TooltipWrapper.vue

@@ -120,17 +120,15 @@ function getArrowPositionStyles(
   coordinations: Partial<Coords>,
   placement: Placement,
 ): CSSProperties {
-  const style: CSSProperties = {};
+  const { x, y } = coordinations; // either X or Y is calculated
-  style.position = 'absolute';
-  const { x, y } = coordinations;
-  if (x) {
-    style.left = `${x}px`;
-  } else if (y) { // either X or Y is calculated
-    style.top = `${y}px`;
-  }
   const oppositeSide = getCounterpartBoxOffsetProperty(placement);
-  style[oppositeSide.toString()] = `-${ARROW_SIZE_IN_PX}px`;
+  const newStyle: CSSProperties = {
-  return style;
+    [oppositeSide]: `-${ARROW_SIZE_IN_PX}px`,
+    position: 'absolute',
+    left: x ? `${x}px` : undefined,
+    top: y ? `${y}px` : undefined,
+  };
+  return newStyle;
 }
 
 function getCounterpartBoxOffsetProperty(placement: Placement): keyof CSSProperties {

src/presentation/electron/main/IpcRegistration.ts

@@ -22,7 +22,8 @@ export function registerAllIpcChannels(
   };
   Object.entries(ipcInstanceCreators).forEach(([name, instanceFactory]) => {
     try {
-      const definition = IpcChannelDefinitions[name];
+      const definitionKey = name as keyof typeof IpcChannelDefinitions;
+      const definition = IpcChannelDefinitions[definitionKey] as IpcChannel<unknown>;
       const instance = instanceFactory();
       registrar(definition, instance);
     } catch (err) {

src/presentation/electron/main/Update/AutomaticUpdateCoordinator.ts

@@ -1,67 +1,106 @@
 import { app, dialog } from 'electron/main';
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
-import { UpdateProgressBar } from './UpdateProgressBar';
+import { UpdateProgressBar } from './ProgressBar/UpdateProgressBar';
 import { getAutoUpdater } from './ElectronAutoUpdaterFactory';
 import type { AppUpdater, UpdateInfo } from 'electron-updater';
 import type { ProgressInfo } from 'electron-builder';
 
 export async function handleAutoUpdate() {
   const autoUpdater = getAutoUpdater();
-  if (await askDownloadAndInstall() === DownloadDialogResult.NotNow) {
+  if (await askDownloadAndInstall() === UpdateDialogResult.Postpone) {
+    ElectronLogger.info('User chose to postpone update');
     return;
   }
-  startHandlingUpdateProgress(autoUpdater);
+  ElectronLogger.info('User chose to download and install update');
-  await autoUpdater.downloadUpdate();
+  try {
-}
+    await startHandlingUpdateProgress(autoUpdater);
-
+  } catch (error) {
-function startHandlingUpdateProgress(autoUpdater: AppUpdater) {
+    ElectronLogger.error('Failed to handle auto-update process', { error });
-  const progressBar = new UpdateProgressBar();
-  progressBar.showIndeterminateState();
-  autoUpdater.on('error', (e) => {
-    progressBar.showError(e);
-  });
-  autoUpdater.on('download-progress', (progress: ProgressInfo) => {
-    /*
-      On macOS, download-progress event is not called.
-      So the indeterminate progress will continue until download is finished.
-    */
-    ElectronLogger.debug('@download-progress@\n', progress);
-    progressBar.showProgress(progress);
-  });
-  autoUpdater.on('update-downloaded', async (info: UpdateInfo) => {
-    ElectronLogger.info('@update-downloaded@\n', info);
-    progressBar.close();
-    await handleUpdateDownloaded(autoUpdater);
-  });
-}
-
-async function handleUpdateDownloaded(autoUpdater: AppUpdater) {
-  if (await askRestartAndInstall() === InstallDialogResult.NotNow) {
-    return;
   }
-  setTimeout(() => autoUpdater.quitAndInstall(), 1);
 }
 
-enum DownloadDialogResult {
+function startHandlingUpdateProgress(autoUpdater: AppUpdater): Promise<void> {
-  Install = 0,
+  return new Promise((resolve, reject) => { // Block until update process completes
-  NotNow = 1,
+    const progressBar = new UpdateProgressBar();
+    progressBar.showIndeterminateState();
+    autoUpdater.on('error', (e) => {
+      progressBar.showError(e);
+      reject(e);
+    });
+    autoUpdater.on('download-progress', (progress: ProgressInfo) => {
+      /*
+        On macOS, download-progress event is not called.
+        So the indeterminate progress will continue until download is finished.
+      */
+      ElectronLogger.debug('Update download progress', { progress });
+      if (progressBar.isOpen) { // May be closed by the user
+        progressBar.showProgress(progress);
+      }
+    });
+    autoUpdater.on('update-downloaded', async (info: UpdateInfo) => {
+      ElectronLogger.info('Update downloaded successfully', { version: info.version });
+      progressBar.closeIfOpen();
+      try {
+        await handleUpdateDownloaded(autoUpdater);
+      } catch (error) {
+        ElectronLogger.error('Failed to handle downloaded update', { error });
+        reject(error);
+      }
+      resolve();
+    });
+    autoUpdater.downloadUpdate();
+  });
 }
-async function askDownloadAndInstall(): Promise<DownloadDialogResult> {
+
+async function handleUpdateDownloaded(
+  autoUpdater: AppUpdater,
+): Promise<void> {
+  return new Promise((resolve, reject) => { // Block until update download process completes
+    askRestartAndInstall()
+      .then((result) => {
+        if (result === InstallDialogResult.InstallAndRestart) {
+          ElectronLogger.info('User chose to install and restart for update');
+          setTimeout(() => {
+            try {
+              autoUpdater.quitAndInstall();
+              resolve();
+            } catch (error) {
+              ElectronLogger.error('Failed to quit and install update', { error });
+              reject(error);
+            }
+          }, 1);
+        } else {
+          ElectronLogger.info('User chose to postpone update installation');
+          resolve();
+        }
+      })
+      .catch((error) => {
+        ElectronLogger.error('Failed to prompt user for restart and install', { error });
+        reject(error);
+      });
+  });
+}
+
+enum UpdateDialogResult {
+  Update = 0,
+  Postpone = 1,
+}
+async function askDownloadAndInstall(): Promise<UpdateDialogResult> {
   const updateDialogResult = await dialog.showMessageBox({
     type: 'question',
     buttons: ['Install', 'Not now'],
     title: 'Confirm Update',
     message: 'Update available.\n\nWould you like to download and install new version?',
     detail: 'Application will automatically restart to apply update after download',
-    defaultId: DownloadDialogResult.Install,
+    defaultId: UpdateDialogResult.Update,
-    cancelId: DownloadDialogResult.NotNow,
+    cancelId: UpdateDialogResult.Postpone,
   });
   return updateDialogResult.response;
 }
 
 enum InstallDialogResult {
   InstallAndRestart = 0,
-  NotNow = 1,
+  Postpone = 1,
 }
 async function askRestartAndInstall(): Promise<InstallDialogResult> {
   const installDialogResult = await dialog.showMessageBox({
@@ -70,7 +109,7 @@ async function askRestartAndInstall(): Promise<InstallDialogResult> {
     message: `A new version of ${app.name} has been downloaded.`,
     detail: 'It will be installed the next time you restart the application.',
     defaultId: InstallDialogResult.InstallAndRestart,
-    cancelId: InstallDialogResult.NotNow,
+    cancelId: InstallDialogResult.Postpone,
   });
   return installDialogResult.response;
 }

src/presentation/electron/main/Update/ManualUpdater/Downloader.ts

@@ -1,10 +1,8 @@
-import { existsSync, createWriteStream, type WriteStream } from 'node:fs';
+import { createWriteStream, type WriteStream } from 'node:fs';
-import { unlink, mkdir } from 'node:fs/promises';
-import path from 'node:path';
-import { app } from 'electron/main';
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
-import { UpdateProgressBar } from '../UpdateProgressBar';
+import type { Logger } from '@/application/Common/Log/Logger';
-import { retryFileSystemAccess } from './RetryFileSystemAccess';
+import { UpdateProgressBar } from '../ProgressBar/UpdateProgressBar';
+import { provideUpdateInstallationFilepath, type InstallationFilepathProvider } from './InstallationFiles/InstallationFilepathProvider';
 import type { UpdateInfo } from 'electron-updater';
 import type { ReadableStream } from 'node:stream/web';
 
@@ -18,18 +16,25 @@ export type DownloadUpdateResult = {
   readonly installerPath: string;
 };
 
+interface UpdateDownloadUtilities {
+  readonly logger: Logger;
+  readonly provideInstallationFilePath: InstallationFilepathProvider;
+}
+
 export async function downloadUpdate(
   info: UpdateInfo,
   remoteFileUrl: string,
   progressBar: UpdateProgressBar,
+  utilities: UpdateDownloadUtilities = DefaultUtilities,
 ): Promise<DownloadUpdateResult> {
-  ElectronLogger.info('Starting manual update download.');
+  utilities.logger.info('Starting manual update download.');
   progressBar.showIndeterminateState();
   try {
     const { filePath } = await downloadInstallerFile(
       info.version,
       remoteFileUrl,
       (percentage) => { progressBar.showPercentage(percentage); },
+      utilities,
     );
     return {
       success: true,
@@ -47,58 +52,40 @@ async function downloadInstallerFile(
   version: string,
   remoteFileUrl: string,
   progressHandler: ProgressCallback,
+  utilities: UpdateDownloadUtilities,
 ): Promise<{ readonly filePath: string; }> {
-  const filePath = `${path.dirname(app.getPath('temp'))}/privacy.sexy/${version}-installer.dmg`;
+  const filePath = await utilities.provideInstallationFilePath(version);
-  if (!await ensureFilePathReady(filePath)) {
-    throw new Error(`Failed to prepare the file path for the installer: ${filePath}`);
-  }
   await downloadFileWithProgress(
     remoteFileUrl,
     filePath,
     progressHandler,
+    utilities,
   );
   return { filePath };
 }
 
-async function ensureFilePathReady(filePath: string): Promise<boolean> {
-  return retryFileSystemAccess(async () => {
-    try {
-      const parentFolder = path.dirname(filePath);
-      if (existsSync(filePath)) {
-        ElectronLogger.info(`Existing update file found and will be replaced: ${filePath}`);
-        await unlink(filePath);
-      } else {
-        await mkdir(parentFolder, { recursive: true });
-      }
-      return true;
-    } catch (error) {
-      ElectronLogger.error(`Failed to prepare file path for update: ${filePath}`, error);
-      return false;
-    }
-  });
-}
-
 type ProgressCallback = (progress: number) => void;
 
 async function downloadFileWithProgress(
   url: string,
   filePath: string,
   progressHandler: ProgressCallback,
+  utilities: UpdateDownloadUtilities,
 ) {
-  // autoUpdater cannot handle DMG files, requiring manual download management for these file types.
+  utilities.logger.info(`Retrieving update from ${url}.`);
-  ElectronLogger.info(`Retrieving update from ${url}.`);
   const response = await fetch(url);
   if (!response.ok) {
     throw Error(`Download failed: Server responded with ${response.status} ${response.statusText}.`);
   }
-  const contentLength = getContentLengthFromResponse(response);
+  const contentLength = getContentLengthFromResponse(response, utilities);
   await withWriteStream(filePath, async (writer) => {
-    ElectronLogger.info(contentLength.isValid
+    utilities.logger.info(contentLength.isValid
-      ? `Saving file to ${filePath} (Size: ${contentLength.totalLength} bytes).`
+      ? `Saving file to '${filePath}' (Size: ${contentLength.totalLength} bytes).`
-      : `Saving file to ${filePath}.`);
+      : `Saving file to '${filePath}'.`);
     await withReadableStream(response, async (reader) => {
-      await streamWithProgress(contentLength, reader, writer, progressHandler);
+      await streamWithProgress(contentLength, reader, writer, progressHandler, utilities);
     });
+    ElectronLogger.info(`Successfully saved the file: '${filePath}'`);
   });
 }
 
@@ -109,16 +96,19 @@ type ResponseContentLength = {
   readonly isValid: false;
 };
 
-function getContentLengthFromResponse(response: Response): ResponseContentLength {
+function getContentLengthFromResponse(
+  response: Response,
+  utilities: UpdateDownloadUtilities,
+): ResponseContentLength {
   const contentLengthString = response.headers.get('content-length');
   const headersInfo = Array.from(response.headers.entries());
   if (!contentLengthString) {
-    ElectronLogger.warn('Missing \'Content-Length\' header in the response.', headersInfo);
+    utilities.logger.warn('Missing \'Content-Length\' header in the response.', headersInfo);
     return { isValid: false };
   }
   const contentLength = Number(contentLengthString);
   if (Number.isNaN(contentLength) || contentLength <= 0) {
-    ElectronLogger.error('Unable to determine download size from server response.', headersInfo);
+    utilities.logger.error('Unable to determine download size from server response.', headersInfo);
     return { isValid: false };
   }
   return { totalLength: contentLength, isValid: true };
@@ -153,6 +143,7 @@ async function streamWithProgress(
   readStream: ReadableStream,
   writeStream: WriteStream,
   progressHandler: ProgressCallback,
+  utilities: UpdateDownloadUtilities,
 ): Promise<void> {
   let receivedLength = 0;
   let logThreshold = 0;
@@ -163,22 +154,23 @@ async function streamWithProgress(
     writeStream.write(Buffer.from(chunk));
     receivedLength += chunk.length;
     notifyProgress(contentLength, receivedLength, progressHandler);
-    const progressLog = logProgress(receivedLength, contentLength, logThreshold);
+    const progressLog = logProgress(receivedLength, contentLength, logThreshold, utilities);
     logThreshold = progressLog.nextLogThreshold;
   }
-  ElectronLogger.info('Update download completed successfully.');
+  utilities.logger.info('Update download completed successfully.');
 }
 
 function logProgress(
   receivedLength: number,
   contentLength: ResponseContentLength,
   logThreshold: number,
+  utilities: UpdateDownloadUtilities,
 ): { readonly nextLogThreshold: number; } {
   const {
     shouldLog, nextLogThreshold,
   } = shouldLogProgress(receivedLength, contentLength, logThreshold);
   if (shouldLog) {
-    ElectronLogger.debug(`Download progress: ${receivedLength} bytes received.`);
+    utilities.logger.debug(`Download progress: ${receivedLength} bytes received.`);
   }
   return { nextLogThreshold };
 }
@@ -220,3 +212,8 @@ function createReader(response: Response): ReadableStream {
   // https://github.com/DefinitelyTyped/DefinitelyTyped/discussions/65542#discussioncomment-6071004
   return response.body as ReadableStream;
 }
+
+const DefaultUtilities: UpdateDownloadUtilities = {
+  logger: ElectronLogger,
+  provideInstallationFilePath: provideUpdateInstallationFilepath,
+};

src/presentation/electron/main/Update/ManualUpdater/FileSystemAccessorWithRetry.ts

@@ -1,15 +1,21 @@
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
 import { sleep } from '@/infrastructure/Threading/AsyncSleep';
 
-export function retryFileSystemAccess(
+export interface FileSystemAccessorWithRetry {
-  fileOperation: () => Promise<boolean>,
+  (
-): Promise<boolean> {
+    fileOperation: () => Promise<boolean>,
+  ): Promise<boolean>;
+}
+
+export const retryFileSystemAccess: FileSystemAccessorWithRetry = (
+  fileOperation,
+) => {
   return retryWithExponentialBackoff(
     fileOperation,
     TOTAL_RETRIES,
     INITIAL_DELAY_MS,
   );
-}
+};
 
 // These values provide a balanced approach for handling transient file system
 // issues without excessive waiting.

src/presentation/electron/main/Update/ManualUpdater/InstallationFiles/InstallationFileCleaner.ts

@@ -0,0 +1,107 @@
+import type { Logger } from '@/application/Common/Log/Logger';
+import type { FileSystemOperations } from '@/infrastructure/FileSystem/FileSystemOperations';
+import type { ApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/ApplicationDirectoryProvider';
+import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
+import { PersistentApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/PersistentApplicationDirectoryProvider';
+import { NodeElectronFileSystemOperations } from '@/infrastructure/FileSystem/NodeElectronFileSystemOperations';
+
+export interface InstallationFileCleaner {
+  (
+    utilities?: UpdateFileUtilities,
+  ): Promise<void>;
+}
+
+interface UpdateFileUtilities {
+  readonly logger: Logger;
+  readonly directoryProvider: ApplicationDirectoryProvider;
+  readonly fileSystem: FileSystemOperations;
+}
+
+export const clearUpdateInstallationFiles: InstallationFileCleaner = async (
+  utilities = DefaultUtilities,
+) => {
+  utilities.logger.info('Starting update installation files cleanup');
+  const { success, error, directoryAbsolutePath } = await utilities.directoryProvider.provideDirectory('update-installation-files');
+  if (!success) {
+    utilities.logger.error('Failed to locate installation files directory', { error });
+    throw new Error('Cannot locate the installation files directory path');
+  }
+  const installationFileNames = await readDirectoryContents(directoryAbsolutePath, utilities);
+  if (installationFileNames.length === 0) {
+    utilities.logger.info('No update installation files found');
+    return;
+  }
+  utilities.logger.debug(`Found ${installationFileNames.length} installation files to delete`);
+  utilities.logger.info('Deleting installation files');
+  const errors = await executeIndependentTasksAndCollectErrors(
+    installationFileNames.map(async (fileOrFolderName) => {
+      await deleteItemFromDirectory(directoryAbsolutePath, fileOrFolderName, utilities);
+    }),
+  );
+  if (errors.length > 0) {
+    utilities.logger.error('Failed to delete some installation files', { errors });
+    throw new Error(`Failed to delete some items:\n${errors.join('\n')}`);
+  }
+  utilities.logger.info('Update installation files cleanup completed successfully');
+};
+
+async function deleteItemFromDirectory(
+  directoryPath: string,
+  fileOrFolderName: string,
+  utilities: UpdateFileUtilities,
+): Promise<void> {
+  const itemPath = utilities.fileSystem.combinePaths(
+    directoryPath,
+    fileOrFolderName,
+  );
+  try {
+    utilities.logger.debug(`Deleting installation artifact: ${itemPath}`);
+    await utilities.fileSystem.deletePath(itemPath);
+    utilities.logger.debug(`Successfully deleted installation artifact: ${itemPath}`);
+  } catch (error) {
+    utilities.logger.error(`Failed to delete installation artifact: ${itemPath}`, { error });
+    throw error;
+  }
+}
+
+async function readDirectoryContents(
+  directoryPath: string,
+  utilities: UpdateFileUtilities,
+): Promise<string[]> {
+  try {
+    utilities.logger.debug(`Reading directory contents: ${directoryPath}`);
+    const items = await utilities.fileSystem.listDirectoryContents(directoryPath);
+    utilities.logger.debug(`Read ${items.length} items from directory: ${directoryPath}`);
+    return items;
+  } catch (error) {
+    utilities.logger.error('Failed to read directory contents', { directoryPath, error });
+    throw new Error('Failed to read directory contents', { cause: error });
+  }
+}
+
+async function executeIndependentTasksAndCollectErrors(
+  tasks: (Promise<void>)[],
+): Promise<string[]> {
+  const results = await Promise.allSettled(tasks);
+  const errors = results
+    .filter((result): result is PromiseRejectedResult => result.status === 'rejected')
+    .map((result) => result.reason);
+  return errors.map((error) => {
+    if (!error) {
+      return 'unknown error';
+    }
+    if (error instanceof Error) {
+      return error.message;
+    }
+    if (typeof error === 'string') {
+      return error;
+    }
+    return String(error);
+  });
+}
+
+const DefaultUtilities: UpdateFileUtilities = {
+  logger: ElectronLogger,
+  directoryProvider: new PersistentApplicationDirectoryProvider(),
+  fileSystem: NodeElectronFileSystemOperations,
+};

src/presentation/electron/main/Update/ManualUpdater/InstallationFiles/InstallationFilepathProvider.ts

@@ -0,0 +1,73 @@
+import type { Logger } from '@/application/Common/Log/Logger';
+import type { ApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/ApplicationDirectoryProvider';
+import { PersistentApplicationDirectoryProvider } from '@/infrastructure/FileSystem/Directory/PersistentApplicationDirectoryProvider';
+import type { FileSystemOperations } from '@/infrastructure/FileSystem/FileSystemOperations';
+import { NodeElectronFileSystemOperations } from '@/infrastructure/FileSystem/NodeElectronFileSystemOperations';
+import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
+import { retryFileSystemAccess, type FileSystemAccessorWithRetry } from '../FileSystemAccessorWithRetry';
+
+export interface InstallationFilepathProvider {
+  (
+    version: string,
+    utilities?: InstallationFilepathProviderUtilities,
+  ): Promise<string>;
+}
+
+interface InstallationFilepathProviderUtilities {
+  readonly logger: Logger;
+  readonly directoryProvider: ApplicationDirectoryProvider;
+  readonly fileSystem: FileSystemOperations;
+  readonly accessFileSystemWithRetry: FileSystemAccessorWithRetry;
+}
+
+export const InstallerFileSuffix = '-installer.dmg';
+
+export const provideUpdateInstallationFilepath: InstallationFilepathProvider = async (
+  version,
+  utilities = DefaultUtilities,
+) => {
+  const {
+    success, error, directoryAbsolutePath,
+  } = await utilities.directoryProvider.provideDirectory('update-installation-files');
+  if (!success) {
+    utilities.logger.error('Error when providing download directory', error);
+    throw new Error('Failed to provide download directory.');
+  }
+  const filepath = utilities.fileSystem.combinePaths(directoryAbsolutePath, `${version}${InstallerFileSuffix}`);
+  if (!await makeFilepathAvailable(filepath, utilities)) {
+    throw new Error(`Failed to prepare the file path for the installer: ${filepath}`);
+  }
+  return filepath;
+};
+
+async function makeFilepathAvailable(
+  filePath: string,
+  utilities: InstallationFilepathProviderUtilities,
+): Promise<boolean> {
+  let isFileAvailable = false;
+  try {
+    isFileAvailable = await utilities.fileSystem.isFileAvailable(filePath);
+  } catch (error) {
+    throw new Error('File availability check failed');
+  }
+  if (!isFileAvailable) {
+    return true;
+  }
+  return utilities.accessFileSystemWithRetry(async () => {
+    try {
+      utilities.logger.info(`Existing update file found and will be replaced: ${filePath}`);
+      await utilities.fileSystem.deletePath(filePath);
+      return true;
+    } catch (error) {
+      utilities.logger.error(`Failed to prepare file path for update: ${filePath}`, error);
+      return false;
+    }
+  });
+}
+
+const DefaultUtilities: InstallationFilepathProviderUtilities = {
+  logger: ElectronLogger,
+  directoryProvider: new PersistentApplicationDirectoryProvider(),
+  fileSystem: NodeElectronFileSystemOperations,
+  accessFileSystemWithRetry: retryFileSystemAccess,
+};

src/presentation/electron/main/Update/ManualUpdater/Installer.ts

@@ -1,7 +1,7 @@
 import { app } from 'electron/main';
 import { shell } from 'electron/common';
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
-import { retryFileSystemAccess } from './RetryFileSystemAccess';
+import { retryFileSystemAccess } from './FileSystemAccessorWithRetry';
 
 export async function startInstallation(filePath: string): Promise<boolean> {
   return retryFileSystemAccess(async () => {

src/presentation/electron/main/Update/ManualUpdater/Integrity.ts

@@ -1,7 +1,7 @@
 import { createHash } from 'node:crypto';
 import { createReadStream } from 'node:fs';
 import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
-import { retryFileSystemAccess } from './RetryFileSystemAccess';
+import { retryFileSystemAccess } from './FileSystemAccessorWithRetry';
 
 export async function checkIntegrity(
   filePath: string,

src/presentation/electron/main/Update/ManualUpdater/ManualUpdateCoordinator.ts

@@ -4,7 +4,7 @@ import { GitHubProjectDetails } from '@/domain/Project/GitHubProjectDetails';
 import { Version } from '@/domain/Version';
 import { parseProjectDetails } from '@/application/Parser/ProjectDetailsParser';
 import { OperatingSystem } from '@/domain/OperatingSystem';
-import { UpdateProgressBar } from '../UpdateProgressBar';
+import { UpdateProgressBar } from '../ProgressBar/UpdateProgressBar';
 import {
   promptForManualUpdate, promptInstallerOpenError,
   promptIntegrityCheckFailure, promptDownloadError,
@@ -14,29 +14,43 @@ import {
 import { type DownloadUpdateResult, downloadUpdate } from './Downloader';
 import { checkIntegrity } from './Integrity';
 import { startInstallation } from './Installer';
+import { clearUpdateInstallationFiles } from './InstallationFiles/InstallationFileCleaner';
 import type { UpdateInfo } from 'electron-updater';
 
-export function requiresManualUpdate(): boolean {
+export function requiresManualUpdate(
-  return process.platform === 'darwin';
+  nodePlatform: string = process.platform,
+): boolean {
+  // autoUpdater cannot handle DMG files, requiring manual download management for these file types.
+  return nodePlatform === 'darwin';
 }
 
 export async function startManualUpdateProcess(info: UpdateInfo) {
+  try {
+    await clearUpdateInstallationFiles();
+  } catch (error) {
+    ElectronLogger.warn('Failed to clear previous update installation files', { error });
+  } finally {
+    await executeManualUpdateProcess(info);
+  }
+}
+
+async function executeManualUpdateProcess(info: UpdateInfo): Promise<void> {
   try {
     const updateAction = await promptForManualUpdate();
     if (updateAction === ManualUpdateChoice.NoAction) {
-      ElectronLogger.info('User cancelled the update.');
+      ElectronLogger.info('User chose to cancel the update');
       return;
     }
     const { releaseUrl, downloadUrl } = getRemoteUpdateUrls(info.version);
     if (updateAction === ManualUpdateChoice.VisitReleasesPage) {
-      ElectronLogger.info(`Navigating to release page: ${releaseUrl}`);
+      ElectronLogger.info('User chose to visit release page', { url: releaseUrl });
       await shell.openExternal(releaseUrl);
     } else if (updateAction === ManualUpdateChoice.UpdateNow) {
-      ElectronLogger.info('Initiating update download and installation.');
+      ElectronLogger.info('User chose to download and install update');
       await downloadAndInstallUpdate(downloadUrl, info);
     }
   } catch (err) {
-    ElectronLogger.error('Unexpected error during updates', err);
+    ElectronLogger.error('Failed to execute auto-update process', { error: err });
     await handleUnexpectedError(info);
   }
 }
@@ -56,9 +70,10 @@ async function downloadAndInstallUpdate(fileUrl: string, info: UpdateInfo) {
   }
   const userAction = await promptIntegrityCheckFailure();
   if (userAction === IntegrityCheckChoice.RetryDownload) {
+    ElectronLogger.info('User chose to retry download after integrity check failure');
     await startManualUpdateProcess(info);
   } else if (userAction === IntegrityCheckChoice.ContinueAnyway) {
-    ElectronLogger.warn('Proceeding to install with failed integrity check.');
+    ElectronLogger.warn('User chose to proceed with installation despite failed integrity check');
     await openInstaller(download.installerPath, info);
   }
 }
@@ -66,9 +81,9 @@ async function downloadAndInstallUpdate(fileUrl: string, info: UpdateInfo) {
 async function handleFailedDownload(info: UpdateInfo) {
   const userAction = await promptDownloadError();
   if (userAction === DownloadErrorChoice.Cancel) {
-    ElectronLogger.info('Update download canceled.');
+    ElectronLogger.info('User chose to cancel update download');
   } else if (userAction === DownloadErrorChoice.RetryDownload) {
-    ElectronLogger.info('Retrying update download.');
+    ElectronLogger.info('User chose to retry update download');
     await startManualUpdateProcess(info);
   }
 }
@@ -76,9 +91,9 @@ async function handleFailedDownload(info: UpdateInfo) {
 async function handleUnexpectedError(info: UpdateInfo) {
   const userAction = await showUnexpectedError();
   if (userAction === UnexpectedErrorChoice.Cancel) {
-    ElectronLogger.info('Unexpected error handling canceled.');
+    ElectronLogger.info('User chose to cancel update process after unexpected error');
   } else if (userAction === UnexpectedErrorChoice.RetryUpdate) {
-    ElectronLogger.info('Retrying the update process.');
+    ElectronLogger.info('User chose to retry update process after unexpected error');
     await startManualUpdateProcess(info);
   }
 }
@@ -89,8 +104,10 @@ async function openInstaller(installerPath: string, info: UpdateInfo) {
   }
   const userAction = await promptInstallerOpenError();
   if (userAction === InstallerErrorChoice.RetryDownload) {
+    ElectronLogger.info('User chose to retry download after installer open error');
     await startManualUpdateProcess(info);
   } else if (userAction === InstallerErrorChoice.RetryOpen) {
+    ElectronLogger.info('User chose to retry opening installer');
     await openInstaller(installerPath, info);
   }
 }
@@ -100,7 +117,7 @@ async function withProgressBar(
 ) {
   const progressBar = new UpdateProgressBar();
   await action(progressBar);
-  progressBar.close();
+  progressBar.closeIfOpen();
 }
 
 async function isIntegrityPreserved(
@@ -119,16 +136,16 @@ async function isIntegrityPreserved(
 function getRemoteSha512Hash(info: UpdateInfo, fileUrl: string): string | undefined {
   const fileInfos = info.files.filter((file) => fileUrl.includes(file.url));
   if (!fileInfos.length) {
-    ElectronLogger.error(`Remote hash not found for the URL: ${fileUrl}`, info.files);
+    ElectronLogger.error('Failed to find remote hash for download URL', { url: fileUrl, files: info.files });
     if (info.files.length > 0) {
       const firstHash = info.files[0].sha512;
-      ElectronLogger.info(`Selecting the first available hash: ${firstHash}`);
+      ElectronLogger.info('Using first available hash due to missing match', { hash: firstHash });
       return firstHash;
     }
     return undefined;
   }
   if (fileInfos.length > 1) {
-    ElectronLogger.error(`Found multiple file entries for the URL: ${fileUrl}`, fileInfos);
+    ElectronLogger.warn('Multiple file entries found for download URL', { url: fileUrl, entries: fileInfos });
   }
   return fileInfos[0].sha512;
 }

src/presentation/electron/main/Update/ProgressBar/ElectronProgressBarWithLifecycle.ts

@@ -0,0 +1,158 @@
+// @ts-expect-error Outdated `@types/electron-progressbar` causes build failure on macOS
+import ProgressBar from 'electron-progressbar';
+import { BrowserWindow } from 'electron/main';
+import { ElectronLogger } from '@/infrastructure/Log/ElectronLogger';
+import type { Logger } from '@/application/Common/Log/Logger';
+import { EventSource } from '@/infrastructure/Events/EventSource';
+import type {
+  InitialProgressBarWindowOptions,
+  ProgressBarUpdater,
+  ProgressBarStatus,
+  ProgressBarUpdateCallback, ProgressBarWithLifecycle,
+} from './ProgressBarWithLifecycle';
+
+/**
+ * It provides a type-safe way to manage `electron-progressbar` instance,
+ * through its lifecycle, ensuring correct usage, state transitions, and cleanup.
+ */
+export class ElectronProgressBarWithLifecycle implements ProgressBarWithLifecycle {
+  private state: ProgressBarWithState = { status: 'closed' };
+
+  public readonly statusChanged = new EventSource<ProgressBarStatus>();
+
+  private readyCallbacks = new Array<ProgressBarUpdateCallback>();
+
+  constructor(
+    private readonly logger: Logger = ElectronLogger,
+  ) { }
+
+  public update(handler: ProgressBarUpdateCallback): void {
+    switch (this.state.status) { // eslint-disable-line default-case
+      case 'closed':
+        // Throwing an error here helps catch bugs early in the development process.
+        throw new Error('Cannot update the progress bar because it is not currently open.');
+      case 'ready':
+        handler(wrapForUpdate(this.state));
+        break;
+      case 'loading':
+        this.readyCallbacks.push(handler);
+        break;
+    }
+  }
+
+  public resetAndOpen(options: InitialProgressBarWindowOptions): void {
+    this.closeIfOpen();
+    const bar = createElectronProgressBar(options);
+    this.state = { status: 'loading', progressBar: bar };
+    bar.on('ready', () => this.handleReadyEvent(bar));
+    bar.on('aborted' /* closed by user */, (value: number) => {
+      this.changeState({ status: 'closed' });
+      this.logger.info(`Progress bar window closed by user. State: ${this.state.status}, Value: ${value}.`);
+    });
+  }
+
+  public closeIfOpen() {
+    if (this.state.status === 'closed') {
+      return;
+    }
+    this.state.progressBar.close();
+    this.changeState({
+      status: 'closed',
+    });
+  }
+
+  private handleReadyEvent(bar: ProgressBar): void {
+    if (this.state.status !== 'loading' || this.state.progressBar !== bar) {
+      // Handle race conditions if `open` called rapidly without closing to avoid leaks
+      this.logger.warn('Unexpected state when handling ready event. Closing the progress bar.');
+      bar.close();
+      return;
+    }
+    const readyBar: ReadyProgressBar = {
+      status: 'ready',
+      progressBar: bar,
+      browserWindow: getWindow(bar),
+    };
+    this.readyCallbacks.forEach((callback) => callback(wrapForUpdate(readyBar)));
+    this.changeState(readyBar);
+  }
+
+  private changeState(newState: ProgressBarWithState): void {
+    if (isSameState(this.state, newState)) {
+      return;
+    }
+    this.readyCallbacks = [];
+    this.state = newState;
+    this.statusChanged.notify(newState.status);
+  }
+}
+
+type ProgressBarWithState = { readonly status: 'closed' }
+| { readonly status: 'loading', readonly progressBar: ProgressBar }
+| ReadyProgressBar;
+
+interface ReadyProgressBar {
+  readonly status: 'ready';
+  readonly progressBar: ProgressBar;
+  readonly browserWindow: BrowserWindow;
+}
+
+function getWindow(bar: ProgressBar): BrowserWindow {
+  // Note: The ProgressBar library does not provide a public method or event
+  // to access the BrowserWindow, so we access the internal `_window` property directly.
+  if (!('_window' in bar)) {
+    throw new Error('Unable to access the progress bar window.');
+  }
+  const browserWindow = bar._window as BrowserWindow; // eslint-disable-line no-underscore-dangle
+  if (!browserWindow) {
+    throw new Error('Missing internal browser window');
+  }
+  return browserWindow;
+}
+
+function isSameState( // eslint-disable-line consistent-return
+  first: ProgressBarWithState,
+  second: ProgressBarWithState,
+): boolean {
+  switch (first.status) { // eslint-disable-line default-case
+    case 'closed':
+      return second.status === 'closed';
+    case 'loading':
+      return second.status === 'loading'
+        && second.progressBar === first.progressBar;
+    case 'ready':
+      return second.status === 'ready'
+        && second.progressBar === first.progressBar
+        && second.browserWindow === first.browserWindow;
+  }
+}
+
+function wrapForUpdate(bar: ReadyProgressBar): ProgressBarUpdater {
+  return {
+    setText: (text: string) => {
+      bar.progressBar.detail = text;
+    },
+    setClosable: (closable: boolean) => {
+      bar.browserWindow.setClosable(closable);
+    },
+    setProgress: (progress: number) => {
+      bar.progressBar.value = progress;
+    },
+  };
+}
+
+function createElectronProgressBar(
+  options: InitialProgressBarWindowOptions,
+): ProgressBar {
+  const bar = new ProgressBar({
+    indeterminate: options.type === 'indeterminate',
+    title: options.title,
+    text: options.initialText,
+  });
+  if (options.type === 'percentile') { // Indeterminate progress bar does not fire `completed` event, see `electron-progressbar` docs
+    bar.on('completed', () => {
+      bar.detail = options.textOnCompleted;
+    });
+  }
+  return bar;
+}

src/presentation/electron/main/Update/ProgressBar/ProgressBarWithLifecycle.ts

@@ -0,0 +1,31 @@
+import type { IEventSource } from '@/infrastructure/Events/IEventSource';
+
+/*
+  Defines interfaces to abstract the progress bar implementation,
+  serving as an anti-corruption layer. This approach allows for
+  flexibility in switching implementations if needed in the future,
+  while maintaining a consistent API for the rest of the application.
+*/
+export interface ProgressBarWithLifecycle {
+  resetAndOpen(options: InitialProgressBarWindowOptions): void;
+  closeIfOpen(): void;
+  update(handler: ProgressBarUpdateCallback): void;
+  readonly statusChanged: IEventSource<ProgressBarStatus>;
+}
+
+export type ProgressBarStatus = 'closed' | 'loading' | 'ready';
+
+export type ProgressBarUpdateCallback = (bar: ProgressBarUpdater) => void;
+
+export interface InitialProgressBarWindowOptions {
+  readonly type: 'indeterminate' | 'percentile';
+  readonly title: string,
+  readonly initialText: string;
+  readonly textOnCompleted: string;
+}
+
+export interface ProgressBarUpdater {
+  setText(text: string): void;
+  setClosable(closable: boolean): void;
+  setProgress(progress: number): void;
+}