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/collection-files.md

@@ -30,6 +30,8 @@ Related documentation:
 
 ### Executables
 
+They represent independently executable actions with documentation and reversibility.
+
 An Executable is a logical entity that can
 
 - execute once compiled,

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",
@@ -28,60 +28,61 @@
     "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",
     "postuninstall": "electron-builder install-app-deps"
   },
   "dependencies": {
-    "@floating-ui/vue": "^1.0.6",
+    "@floating-ui/vue": "^1.1.1",
     "@juggle/resize-observer": "^3.4.0",
-    "ace-builds": "^1.33.0",
+    "ace-builds": "^1.35.3",
-    "electron-log": "^5.1.2",
+    "electron-log": "^5.1.6",
     "electron-progressbar": "^2.2.1",
-    "electron-updater": "^6.1.9",
+    "electron-updater": "^6.2.1",
     "file-saver": "^2.0.5",
     "markdown-it": "^14.1.0",
-    "vue": "^3.4.27"
+    "vue": "^3.4.32"
   },
   "devDependencies": {
     "@modyfi/vite-plugin-yaml": "^1.1.0",
-    "@rushstack/eslint-patch": "^1.10.2",
+    "@rushstack/eslint-patch": "^1.10.3",
     "@types/ace": "^0.0.52",
     "@types/file-saver": "^2.0.7",
-    "@types/markdown-it": "^14.0.1",
+    "@types/markdown-it": "^14.1.1",
     "@typescript-eslint/eslint-plugin": "6.21.0",
     "@typescript-eslint/parser": "6.21.0",
-    "@vitejs/plugin-legacy": "^5.3.2",
+    "@vitejs/plugin-legacy": "^5.4.1",
-    "@vitejs/plugin-vue": "^5.0.4",
+    "@vitejs/plugin-vue": "^5.0.5",
     "@vue/eslint-config-airbnb-with-typescript": "^8.0.0",
     "@vue/eslint-config-typescript": "12.0.0",
-    "@vue/test-utils": "^2.4.5",
+    "@vue/test-utils": "^2.4.6",
     "autoprefixer": "^10.4.19",
-    "cypress": "^13.7.3",
+    "cypress": "^13.13.1",
-    "electron": "^31.0.2",
+    "electron": "^31.2.1",
     "electron-builder": "^24.13.3",
     "electron-devtools-installer": "^3.2.0",
-    "electron-vite": "^2.1.0",
+    "electron-vite": "^2.3.0",
     "eslint": "8.57.0",
-    "eslint-plugin-cypress": "^2.15.1",
+    "eslint-plugin-cypress": "^3.3.0",
-    "eslint-plugin-vue": "^9.25.0",
+    "eslint-plugin-vue": "^9.27.0",
-    "eslint-plugin-vuejs-accessibility": "^2.2.1",
+    "eslint-plugin-vuejs-accessibility": "^2.4.0",
-    "jsdom": "^24.0.0",
+    "jsdom": "^24.1.0",
-    "markdownlint-cli": "^0.39.0",
+    "markdownlint-cli": "^0.41.0",
-    "postcss": "^8.4.38",
+    "postcss": "^8.4.39",
-    "remark-cli": "^12.0.0",
+    "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": "^1.75.0",
+    "sass": "~1.79.4",
-    "start-server-and-test": "^2.0.3",
+    "start-server-and-test": "^2.0.4",
-    "terser": "^5.30.3",
+    "terser": "^5.31.3",
-    "tslib": "^2.6.2",
+    "tslib": "^2.6.3",
-    "typescript": "^5.4.5",
+    "typescript": "~5.5.4",
-    "vite": "^5.2.8",
+    "vite": "^5.4.8",
-    "vitest": "^1.5.0",
+    "vitest": "^2.0.3",
-    "vue-tsc": "^2.0.13",
+    "vue-tsc": "^2.0.26",
     "yaml-lint": "^1.7.0"
   },
   "//devDependencies": {

scripts/verify-build-artifacts.js

@@ -91,7 +91,7 @@ async function verifyFilesExist(directoryPath, filePatterns) {
     if (!match) {
       die(
         `No file matches the pattern ${pattern.source} in directory \`${directoryPath}\``,
-        `\nFiles in directory:\n${files.map((file) => `\t- ${file}`).join('\n')}`,
+        `\nFiles in directory:\n${files.map((file) => `- ${file}`).join('\n')}`,
       );
     }
   }

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/Common/Text/FilterEmptyStrings.ts

@@ -0,0 +1,25 @@
+import { isArray } from '@/TypeHelpers';
+
+export type OptionalString = string | undefined | null;
+
+export function filterEmptyStrings(
+  texts: readonly OptionalString[],
+  isArrayType: typeof isArray = isArray,
+): string[] {
+  if (!isArrayType(texts)) {
+    throw new Error(`Invalid input: Expected an array, but received type ${typeof texts}.`);
+  }
+  assertArrayItemsAreStringLike(texts);
+  return texts
+    .filter((title): title is string => Boolean(title));
+}
+
+function assertArrayItemsAreStringLike(
+  texts: readonly unknown[],
+): asserts texts is readonly OptionalString[] {
+  const invalidItems = texts.filter((item) => !(typeof item === 'string' || item === undefined || item === null));
+  if (invalidItems.length > 0) {
+    const invalidTypes = invalidItems.map((item) => typeof item).join(', ');
+    throw new Error(`Invalid array items: Expected items as string, undefined, or null. Received invalid types: ${invalidTypes}.`);
+  }
+}

src/application/Common/Text/IndentText.ts

@@ -0,0 +1,29 @@
+import { isString } from '@/TypeHelpers';
+import { splitTextIntoLines } from './SplitTextIntoLines';
+
+export function indentText(
+  text: string,
+  indentLevel = 1,
+  utilities: TextIndentationUtilities = DefaultUtilities,
+): string {
+  if (!utilities.isStringType(text)) {
+    throw new Error(`Indentation error: The input must be a string. Received type: ${typeof text}.`);
+  }
+  if (indentLevel <= 0) {
+    throw new Error(`Indentation error: The indent level must be a positive integer. Received: ${indentLevel}.`);
+  }
+  const indentation = '\t'.repeat(indentLevel);
+  return utilities.splitIntoLines(text)
+    .map((line) => (line ? `${indentation}${line}` : line))
+    .join('\n');
+}
+
+interface TextIndentationUtilities {
+  readonly splitIntoLines: typeof splitTextIntoLines;
+  readonly isStringType: typeof isString;
+}
+
+const DefaultUtilities: TextIndentationUtilities = {
+  splitIntoLines: splitTextIntoLines,
+  isStringType: isString,
+};

src/application/Common/Text/SplitTextIntoLines.ts

@@ -0,0 +1,11 @@
+import { isString } from '@/TypeHelpers';
+
+export function splitTextIntoLines(
+  text: string,
+  isStringType = isString,
+): string[] {
+  if (!isStringType(text)) {
+    throw new Error(`Line splitting error: Expected a string but received type '${typeof text}'.`);
+  }
+  return text.split(/\r\n|\r|\n/);
+}

src/application/Context/ApplicationContext.ts

@@ -1,6 +1,6 @@
 import type { IApplication } from '@/domain/IApplication';
 import { OperatingSystem } from '@/domain/OperatingSystem';
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import { EventSource } from '@/infrastructure/Events/EventSource';
 import { assertInRange } from '@/application/Common/Enum';
 import { CategoryCollectionState } from './State/CategoryCollectionState';
@@ -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/Context/State/CategoryCollectionState.ts

@@ -1,4 +1,4 @@
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import { OperatingSystem } from '@/domain/OperatingSystem';
 import { AdaptiveFilterContext } from './Filter/AdaptiveFilterContext';
 import { ApplicationCode } from './Code/ApplicationCode';

src/application/Context/State/Code/Event/CodeChangedEvent.ts

@@ -1,6 +1,8 @@
 import type { Script } from '@/domain/Executables/Script/Script';
 import type { ICodePosition } from '@/application/Context/State/Code/Position/ICodePosition';
 import type { SelectedScript } from '@/application/Context/State/Selection/Script/SelectedScript';
+import { splitTextIntoLines } from '@/application/Common/Text/SplitTextIntoLines';
+import type { ExecutableId } from '@/domain/Executables/Identifiable';
 import type { ICodeChangedEvent } from './ICodeChangedEvent';
 
 export class CodeChangedEvent implements ICodeChangedEvent {
@@ -36,12 +38,12 @@ export class CodeChangedEvent implements ICodeChangedEvent {
   }
 
   public getScriptPositionInCode(script: Script): ICodePosition {
-    return this.getPositionById(script.id);
+    return this.getPositionById(script.executableId);
   }
 
-  private getPositionById(scriptId: string): ICodePosition {
+  private getPositionById(scriptId: ExecutableId): ICodePosition {
     const position = [...this.scripts.entries()]
-      .filter(([s]) => s.id === scriptId)
+      .filter(([s]) => s.executableId === scriptId)
       .map(([, pos]) => pos)
       .at(0);
     if (!position) {
@@ -52,12 +54,12 @@ export class CodeChangedEvent implements ICodeChangedEvent {
 }
 
 function ensureAllPositionsExist(script: string, positions: ReadonlyArray<ICodePosition>) {
-  const totalLines = script.split(/\r\n|\r|\n/).length;
+  const totalLines = splitTextIntoLines(script).length;
   const missingPositions = positions.filter((position) => position.endLine > totalLines);
   if (missingPositions.length > 0) {
     throw new Error(
       `Out of range script end line: "${missingPositions.map((pos) => pos.endLine).join('", "')}"`
-        + `(total code lines: ${totalLines}).`,
+        + ` (total code lines: ${totalLines}).`,
     );
   }
 }

src/application/Context/State/Code/Generation/CodeBuilder.ts

@@ -1,3 +1,4 @@
+import { splitTextIntoLines } from '@/application/Common/Text/SplitTextIntoLines';
 import type { ICodeBuilder } from './ICodeBuilder';
 
 const TotalFunctionSeparatorChars = 58;
@@ -15,7 +16,7 @@ export abstract class CodeBuilder implements ICodeBuilder {
       this.lines.push('');
       return this;
     }
-    const lines = code.match(/[^\r\n]+/g);
+    const lines = splitTextIntoLines(code);
     if (lines) {
       this.lines.push(...lines);
     }

src/application/Context/State/Filter/AdaptiveFilterContext.ts

@@ -1,5 +1,5 @@
 import { EventSource } from '@/infrastructure/Events/EventSource';
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import { FilterChange } from './Event/FilterChange';
 import { LinearFilterStrategy } from './Strategy/LinearFilterStrategy';
 import type { FilterResult } from './Result/FilterResult';

src/application/Context/State/Filter/Strategy/FilterStrategy.ts

@@ -1,4 +1,4 @@
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import type { FilterResult } from '../Result/FilterResult';
 
 export interface FilterStrategy {

src/application/Context/State/Filter/Strategy/LinearFilterStrategy.ts

@@ -1,7 +1,7 @@
 import type { Category } from '@/domain/Executables/Category/Category';
 import type { ScriptCode } from '@/domain/Executables/Script/Code/ScriptCode';
 import type { Documentable } from '@/domain/Executables/Documentable';
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import type { Script } from '@/domain/Executables/Script/Script';
 import { AppliedFilterResult } from '../Result/AppliedFilterResult';
 import type { FilterStrategy } from './FilterStrategy';

src/application/Context/State/ICategoryCollectionState.ts

@@ -1,4 +1,4 @@
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import { OperatingSystem } from '@/domain/OperatingSystem';
 import type { IApplicationCode } from './Code/IApplicationCode';
 import type { ReadonlyFilterContext, FilterContext } from './Filter/FilterContext';

src/application/Context/State/Selection/Category/CategorySelectionChange.ts

@@ -1,3 +1,5 @@
+import type { ExecutableId } from '@/domain/Executables/Identifiable';
+
 type CategorySelectionStatus = {
   readonly isSelected: true;
   readonly isReverted: boolean;
@@ -6,7 +8,7 @@ type CategorySelectionStatus = {
 };
 
 export interface CategorySelectionChange {
-  readonly categoryId: number;
+  readonly categoryId: ExecutableId;
   readonly newStatus: CategorySelectionStatus;
 }
 

src/application/Context/State/Selection/Category/ScriptToCategorySelectionMapper.ts

@@ -1,5 +1,5 @@
 import type { Category } from '@/domain/Executables/Category/Category';
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import type { CategorySelectionChange, CategorySelectionChangeCommand } from './CategorySelectionChange';
 import type { CategorySelection } from './CategorySelection';
 import type { ScriptSelection } from '../Script/ScriptSelection';
@@ -23,7 +23,7 @@ export class ScriptToCategorySelectionMapper implements CategorySelection {
       return false;
     }
     return scripts.every(
-      (script) => selectedScripts.some((selected) => selected.id === script.id),
+      (script) => selectedScripts.some((selected) => selected.id === script.executableId),
     );
   }
 
@@ -50,7 +50,7 @@ export class ScriptToCategorySelectionMapper implements CategorySelection {
     const scripts = category.getAllScriptsRecursively();
     const scriptsChangesInCategory = scripts
       .map((script): ScriptSelectionChange => ({
-        scriptId: script.id,
+        scriptId: script.executableId,
         newStatus: {
           ...change.newStatus,
         },

src/application/Context/State/Selection/Script/DebouncedScriptSelection.ts

@@ -2,8 +2,9 @@ import { InMemoryRepository } from '@/infrastructure/Repository/InMemoryReposito
 import type { Script } from '@/domain/Executables/Script/Script';
 import { EventSource } from '@/infrastructure/Events/EventSource';
 import type { ReadonlyRepository, Repository } from '@/application/Repository/Repository';
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import { batchedDebounce } from '@/application/Common/Timing/BatchedDebounce';
+import type { ExecutableId } from '@/domain/Executables/Identifiable';
 import { UserSelectedScript } from './UserSelectedScript';
 import type { ScriptSelection } from './ScriptSelection';
 import type { ScriptSelectionChange, ScriptSelectionChangeCommand } from './ScriptSelectionChange';
@@ -16,7 +17,7 @@ export type DebounceFunction = typeof batchedDebounce<ScriptSelectionChangeComma
 export class DebouncedScriptSelection implements ScriptSelection {
   public readonly changed = new EventSource<ReadonlyArray<SelectedScript>>();
 
-  private readonly scripts: Repository<string, SelectedScript>;
+  private readonly scripts: Repository<SelectedScript>;
 
   public readonly processChanges: ScriptSelection['processChanges'];
 
@@ -25,7 +26,7 @@ export class DebouncedScriptSelection implements ScriptSelection {
     selectedScripts: ReadonlyArray<SelectedScript>,
     debounce: DebounceFunction = batchedDebounce,
   ) {
-    this.scripts = new InMemoryRepository<string, SelectedScript>();
+    this.scripts = new InMemoryRepository<SelectedScript>();
     for (const script of selectedScripts) {
       this.scripts.addItem(script);
     }
@@ -38,8 +39,8 @@ export class DebouncedScriptSelection implements ScriptSelection {
     );
   }
 
-  public isSelected(scriptId: string): boolean {
+  public isSelected(scriptExecutableId: ExecutableId): boolean {
-    return this.scripts.exists(scriptId);
+    return this.scripts.exists(scriptExecutableId);
   }
 
   public get selectedScripts(): readonly SelectedScript[] {
@@ -49,7 +50,7 @@ export class DebouncedScriptSelection implements ScriptSelection {
   public selectAll(): void {
     const scriptsToSelect = this.collection
       .getAllScripts()
-      .filter((script) => !this.scripts.exists(script.id))
+      .filter((script) => !this.scripts.exists(script.executableId))
       .map((script) => new UserSelectedScript(script, false));
     if (scriptsToSelect.length === 0) {
       return;
@@ -116,12 +117,12 @@ export class DebouncedScriptSelection implements ScriptSelection {
   private applyChange(change: ScriptSelectionChange): number {
     const script = this.collection.getScript(change.scriptId);
     if (change.newStatus.isSelected) {
-      return this.addOrUpdateScript(script.id, change.newStatus.isReverted);
+      return this.addOrUpdateScript(script.executableId, change.newStatus.isReverted);
     }
-    return this.removeScript(script.id);
+    return this.removeScript(script.executableId);
   }
 
-  private addOrUpdateScript(scriptId: string, revert: boolean): number {
+  private addOrUpdateScript(scriptId: ExecutableId, revert: boolean): number {
     const script = this.collection.getScript(scriptId);
     const selectedScript = new UserSelectedScript(script, revert);
     if (!this.scripts.exists(selectedScript.id)) {
@@ -136,7 +137,7 @@ export class DebouncedScriptSelection implements ScriptSelection {
     return 1;
   }
 
-  private removeScript(scriptId: string): number {
+  private removeScript(scriptId: ExecutableId): number {
     if (!this.scripts.exists(scriptId)) {
       return 0;
     }
@@ -152,24 +153,24 @@ function assertNonEmptyScriptSelection(selectedItems: readonly Script[]) {
 }
 
 function getScriptIdsToBeSelected(
-  existingItems: ReadonlyRepository<string, SelectedScript>,
+  existingItems: ReadonlyRepository<SelectedScript>,
   desiredScripts: readonly Script[],
 ): string[] {
   return desiredScripts
-    .filter((script) => !existingItems.exists(script.id))
+    .filter((script) => !existingItems.exists(script.executableId))
-    .map((script) => script.id);
+    .map((script) => script.executableId);
 }
 
 function getScriptIdsToBeDeselected(
-  existingItems: ReadonlyRepository<string, SelectedScript>,
+  existingItems: ReadonlyRepository<SelectedScript>,
   desiredScripts: readonly Script[],
 ): string[] {
   return existingItems
     .getItems()
-    .filter((existing) => !desiredScripts.some((script) => existing.id === script.id))
+    .filter((existing) => !desiredScripts.some((script) => existing.id === script.executableId))
     .map((script) => script.id);
 }
 
 function equals(a: SelectedScript, b: SelectedScript): boolean {
-  return a.script.equals(b.script.id) && a.revert === b.revert;
+  return a.script.executableId === b.script.executableId && a.revert === b.revert;
 }

src/application/Context/State/Selection/Script/ScriptSelection.ts

@@ -1,12 +1,13 @@
 import type { IEventSource } from '@/infrastructure/Events/IEventSource';
 import type { Script } from '@/domain/Executables/Script/Script';
+import type { ExecutableId } from '@/domain/Executables/Identifiable';
 import type { SelectedScript } from './SelectedScript';
 import type { ScriptSelectionChangeCommand } from './ScriptSelectionChange';
 
 export interface ReadonlyScriptSelection {
   readonly changed: IEventSource<readonly SelectedScript[]>;
   readonly selectedScripts: readonly SelectedScript[];
-  isSelected(scriptId: string): boolean;
+  isSelected(scriptExecutableId: ExecutableId): boolean;
 }
 
 export interface ScriptSelection extends ReadonlyScriptSelection {

src/application/Context/State/Selection/Script/ScriptSelectionChange.ts

@@ -1,3 +1,5 @@
+import type { ExecutableId } from '@/domain/Executables/Identifiable';
+
 export type ScriptSelectionStatus = {
   readonly isSelected: true;
   readonly isReverted: boolean;
@@ -7,7 +9,7 @@ export type ScriptSelectionStatus = {
 };
 
 export interface ScriptSelectionChange {
-  readonly scriptId: string;
+  readonly scriptId: ExecutableId;
   readonly newStatus: ScriptSelectionStatus;
 }
 

src/application/Context/State/Selection/Script/SelectedScript.ts

@@ -1,9 +1,7 @@
-import type { IEntity } from '@/infrastructure/Entity/IEntity';
 import type { Script } from '@/domain/Executables/Script/Script';
+import type { RepositoryEntity } from '@/application/Repository/RepositoryEntity';
 
-type ScriptId = Script['id'];
+export interface SelectedScript extends RepositoryEntity {
-
-export interface SelectedScript extends IEntity<ScriptId> {
   readonly script: Script;
   readonly revert: boolean;
 }

src/application/Context/State/Selection/Script/UserSelectedScript.ts

@@ -1,17 +1,16 @@
-import { BaseEntity } from '@/infrastructure/Entity/BaseEntity';
 import type { Script } from '@/domain/Executables/Script/Script';
-import type { SelectedScript } from './SelectedScript';
+import type { RepositoryEntity } from '@/application/Repository/RepositoryEntity';
 
-type SelectedScriptId = SelectedScript['id'];
+export class UserSelectedScript implements RepositoryEntity {
+  public readonly id: string;
 
-export class UserSelectedScript extends BaseEntity<SelectedScriptId> {
   constructor(
     public readonly script: Script,
     public readonly revert: boolean,
   ) {
-    super(script.id);
+    this.id = script.executableId;
     if (revert && !script.canRevert()) {
-      throw new Error(`The script with ID '${script.id}' is not reversible and cannot be reverted.`);
+      throw new Error(`The script with ID '${script.executableId}' is not reversible and cannot be reverted.`);
     }
   }
 }

src/application/Context/State/Selection/UserSelectionFacade.ts

@@ -1,4 +1,4 @@
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
 import { ScriptToCategorySelectionMapper } from './Category/ScriptToCategorySelectionMapper';
 import { DebouncedScriptSelection } from './Script/DebouncedScriptSelection';
 import type { CategorySelection } from './Category/CategorySelection';

src/application/Parser/ApplicationParser.ts

@@ -31,7 +31,7 @@ function validateCollectionsData(
 ) {
   validator.assertNonEmptyCollection({
     value: collections,
-    valueName: 'collections',
+    valueName: 'Collections',
   });
 }
 

src/application/Parser/CategoryCollectionParser.ts

@@ -1,13 +1,13 @@
 import type { CollectionData } from '@/application/collections/';
 import { OperatingSystem } from '@/domain/OperatingSystem';
-import type { ICategoryCollection } from '@/domain/ICategoryCollection';
+import type { ICategoryCollection } from '@/domain/Collection/ICategoryCollection';
-import { CategoryCollection } from '@/domain/CategoryCollection';
+import { CategoryCollection } from '@/domain/Collection/CategoryCollection';
 import type { ProjectDetails } from '@/domain/Project/ProjectDetails';
 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({
@@ -45,14 +45,14 @@ function validateCollection(
 ): void {
   validator.assertObject({
     value: content,
-    valueName: 'collection',
+    valueName: 'Collection',
     allowedProperties: [
       'os', 'scripting', 'actions', 'functions',
     ],
   });
   validator.assertNonEmptyCollection({
     value: content.actions,
-    valueName: '"actions" in collection',
+    valueName: '\'actions\' in collection',
   });
 }
 
@@ -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/Common/ContextualError.ts

@@ -1,42 +1,116 @@
 import { CustomError } from '@/application/Common/CustomError';
+import { indentText } from '@/application/Common/Text/IndentText';
 
 export interface ErrorWithContextWrapper {
   (
-    error: Error,
+    innerError: Error,
     additionalContext: string,
   ): Error;
 }
 
 export const wrapErrorWithAdditionalContext: ErrorWithContextWrapper = (
-  error: Error,
+  innerError,
-  additionalContext: string,
+  additionalContext,
 ) => {
-  return (error instanceof ContextualError ? error : new ContextualError(error))
+  if (!additionalContext) {
-    .withAdditionalContext(additionalContext);
+    throw new Error('Missing additional context');
+  }
+  return new ContextualError({
+    innerError,
+    additionalContext,
+  });
 };
 
-/* AggregateError is similar but isn't well-serialized or displayed by browsers */
+/**
+ * Class for building a detailed error trace.
+ *
+ * Alternatives considered:
+ * - `AggregateError`:
+ *   Similar but not well-serialized or displayed by browsers such as Chromium (last tested v126).
+ * - `cause` property:
+ *   Not displayed by all browsers (last tested v126).
+ *   Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause
+ *
+ * This is immutable where the constructor sets the values because using getter functions such as
+ * `get cause()`, `get message()` does not work on Chromium (last tested v126), but works fine on
+ * Firefox (last tested v127).
+ */
 class ContextualError extends CustomError {
-  private readonly additionalContext = new Array<string>();
+  constructor(public readonly context: ErrorContext) {
-
+    super(
-  constructor(
+      generateDetailedErrorMessageWithContext(context),
-    public readonly innerError: Error,
+      {
-  ) {
+        cause: context.innerError,
-    super();
+      },
-  }
+    );
-
-  public withAdditionalContext(additionalContext: string): this {
-    this.additionalContext.push(additionalContext);
-    return this;
-  }
-
-  public get message(): string { // toString() is not used when Chromium logs it on console
-    return [
-      '\n',
-      this.innerError.message,
-      '\n',
-      'Additional context:',
-      ...this.additionalContext.map((context, index) => `${index + 1}: ${context}`),
-    ].join('\n');
   }
 }
+
+interface ErrorContext {
+  readonly innerError: Error;
+  readonly additionalContext: string;
+}
+
+function generateDetailedErrorMessageWithContext(
+  context: ErrorContext,
+): string {
+  return [
+    '\n',
+    // Display the current error message first, then the root cause.
+    // This prevents repetitive main messages for errors with a `cause:` chain,
+    // aligning with browser error display conventions.
+    context.additionalContext,
+    '\n',
+    'Error Trace (starting from root cause):',
+    indentText(
+      formatErrorTrace(
+        // Displaying contexts from the top frame (deepest, most recent) aligns with
+        // common debugger/compiler standard.
+        extractErrorTraceAscendingFromDeepest(context),
+      ),
+    ),
+    '\n',
+  ].join('\n');
+}
+
+function extractErrorTraceAscendingFromDeepest(
+  context: ErrorContext,
+): string[] {
+  const originalError = findRootError(context.innerError);
+  const contextsDescendingFromMostRecent: string[] = [
+    context.additionalContext,
+    ...gatherContextsFromErrorChain(context.innerError),
+    originalError.toString(),
+  ];
+  const contextsAscendingFromDeepest = contextsDescendingFromMostRecent.reverse();
+  return contextsAscendingFromDeepest;
+}
+
+function findRootError(error: Error): Error {
+  if (error instanceof ContextualError) {
+    return findRootError(error.context.innerError);
+  }
+  return error;
+}
+
+function gatherContextsFromErrorChain(
+  error: Error,
+  accumulatedContexts: string[] = [],
+): string[] {
+  if (error instanceof ContextualError) {
+    accumulatedContexts.push(error.context.additionalContext);
+    return gatherContextsFromErrorChain(error.context.innerError, accumulatedContexts);
+  }
+  return accumulatedContexts;
+}
+
+function formatErrorTrace(
+  errorMessages: readonly string[],
+): string {
+  if (errorMessages.length === 1) {
+    return errorMessages[0];
+  }
+  return errorMessages
+    .map((context, index) => `${index + 1}.${indentText(context)}`)
+    .join('\n');
+}

src/application/Parser/Common/TypeValidator.ts

@@ -108,7 +108,7 @@ function assertArray(
   valueName: string,
 ): asserts value is Array<unknown> {
   if (!isArray(value)) {
-    throw new Error(`'${valueName}' should be of type 'array', but is of type '${typeof value}'.`);
+    throw new Error(`${valueName} should be of type 'array', but is of type '${typeof value}'.`);
   }
 }
 
@@ -117,7 +117,7 @@ function assertString(
   valueName: string,
 ): asserts value is string {
   if (!isString(value)) {
-    throw new Error(`'${valueName}' should be of type 'string', but is of type '${typeof value}'.`);
+    throw new Error(`${valueName} should be of type 'string', but is of type '${typeof value}'.`);
   }
 }
 

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

@@ -3,24 +3,22 @@ import type {
 } from '@/application/collections/';
 import { wrapErrorWithAdditionalContext, type ErrorWithContextWrapper } from '@/application/Parser/Common/ContextualError';
 import type { Category } from '@/domain/Executables/Category/Category';
-import { CollectionCategory } from '@/domain/Executables/Category/CollectionCategory';
 import type { Script } from '@/domain/Executables/Script/Script';
+import { createCategory, type CategoryFactory } from '@/domain/Executables/Category/CategoryFactory';
 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';
-
-let categoryIdCounter = 0;
 
 export const parseCategory: CategoryParser = (
   category: CategoryData,
-  collectionUtilities: CategoryCollectionSpecificUtilities,
+  collectionContext: CategoryCollectionContext,
   categoryUtilities: CategoryParserUtilities = DefaultCategoryParserUtilities,
 ) => {
   return parseCategoryRecursively({
     categoryData: category,
-    collectionUtilities,
+    collectionContext,
     categoryUtilities,
   });
 };
@@ -28,14 +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;
 }
@@ -54,12 +52,12 @@ function parseCategoryRecursively(
       children,
       parent: context.categoryData,
       categoryUtilities: context.categoryUtilities,
-      collectionUtilities: context.collectionUtilities,
+      collectionContext: context.collectionContext,
     });
   }
   try {
     return context.categoryUtilities.createCategory({
-      id: categoryIdCounter++,
+      executableId: context.categoryData.category, // Pseudo-ID for uniqueness until real ID support
       name: context.categoryData.category,
       docs: context.categoryUtilities.parseDocs(context.categoryData),
       subcategories: children.subcategories,
@@ -84,7 +82,7 @@ function ensureValidCategory(
   });
   validator.assertType((v) => v.assertObject({
     value: category,
-    valueName: category.category ?? 'category',
+    valueName: category.category ? `Category '${category.category}'` : 'Category',
     allowedProperties: [
       'docs', 'children', 'category',
     ],
@@ -106,7 +104,7 @@ interface ExecutableParseContext {
   readonly data: ExecutableData;
   readonly children: CategoryChildren;
   readonly parent: CategoryData;
-  readonly collectionUtilities: CategoryCollectionSpecificUtilities;
+  readonly collectionContext: CategoryCollectionContext;
   readonly categoryUtilities: CategoryParserUtilities;
 }
 
@@ -126,13 +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);
   }
 }
@@ -166,10 +164,6 @@ function hasProperty(
   return Object.prototype.hasOwnProperty.call(object, propertyName);
 }
 
-export type CategoryFactory = (
-  ...parameters: ConstructorParameters<typeof CollectionCategory>
-) => Category;
-
 interface CategoryParserUtilities {
   readonly createCategory: CategoryFactory;
   readonly wrapError: ErrorWithContextWrapper;
@@ -179,7 +173,7 @@ interface CategoryParserUtilities {
 }
 
 const DefaultCategoryParserUtilities: CategoryParserUtilities = {
-  createCategory: (...parameters) => new CollectionCategory(...parameters),
+  createCategory,
   wrapError: wrapErrorWithAdditionalContext,
   createValidator: createExecutableDataValidator,
   parseScript,

src/application/Parser/Executable/Script/Compiler/Expressions/Pipes/Pipe.ts

@@ -1,4 +1,4 @@
-export interface IPipe {
+export interface Pipe {
   readonly name: string;
   apply(input: string): string;
 }

src/application/Parser/Executable/Script/Compiler/Expressions/Pipes/PipeDefinitions/EscapeDoubleQuotes.ts

@@ -1,11 +1,11 @@
-import type { IPipe } from '../IPipe';
+import type { Pipe } from '../Pipe';
 
-export class EscapeDoubleQuotes implements IPipe {
+export class EscapeDoubleQuotes implements Pipe {
   public readonly name: string = 'escapeDoubleQuotes';
 
   public apply(raw: string): string {
     if (!raw) {
-      return raw;
+      return '';
     }
     return raw.replaceAll('"', '"^""');
     /* eslint-disable vue/max-len */

src/application/Parser/Executable/Script/Compiler/Expressions/Pipes/PipeDefinitions/InlinePowerShell.ts

@@ -1,6 +1,7 @@
-import type { IPipe } from '../IPipe';
+import { splitTextIntoLines } from '@/application/Common/Text/SplitTextIntoLines';
+import type { Pipe } from '../Pipe';
 
-export class InlinePowerShell implements IPipe {
+export class InlinePowerShell implements Pipe {
   public readonly name: string = 'inlinePowerShell';
 
   public apply(code: string): string {
@@ -8,9 +9,11 @@ export class InlinePowerShell implements IPipe {
       return code;
     }
     const processor = new Array<(data: string) => string>(...[ // for broken ESlint "indent"
+      // Order is important
       inlineComments,
-      mergeLinesWithBacktick,
       mergeHereStrings,
+      mergeLinesWithBacktick,
+      mergeLinesWithBracketCodeBlocks,
       mergeNewLines,
     ]).reduce((a, b) => (data) => b(a(data)));
     const newCode = processor(code);
@@ -89,10 +92,6 @@ function inlineComments(code: string): string {
     */
 }
 
-function getLines(code: string): string[] {
-  return (code?.split(/\r\n|\r|\n/) || []);
-}
-
 /*
   Merges inline here-strings to a single lined string with Windows line terminator (\r\n)
   https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_quoting_rules?view=powershell-7.4#here-strings
@@ -102,18 +101,18 @@ function mergeHereStrings(code: string) {
   return code.replaceAll(regex, (_$, quotes, scope) => {
     const newString = getHereStringHandler(quotes);
     const escaped = scope.replaceAll(quotes, newString.escapedQuotes);
-    const lines = getLines(escaped);
+    const lines = splitTextIntoLines(escaped);
     const inlined = lines.join(newString.separator);
     const quoted = `${newString.quotesAround}${inlined}${newString.quotesAround}`;
     return quoted;
   });
 }
-interface IInlinedHereString {
+interface InlinedHereString {
   readonly quotesAround: string;
   readonly escapedQuotes: string;
   readonly separator: string;
 }
-function getHereStringHandler(quotes: string): IInlinedHereString {
+function getHereStringHandler(quotes: string): InlinedHereString {
   /*
     We handle @' and @" differently.
     Single quotes are interpreted literally and doubles are expandable.
@@ -158,9 +157,33 @@ function mergeLinesWithBacktick(code: string) {
   return code.replaceAll(/ +`\s*(?:\r\n|\r|\n)\s*/g, ' ');
 }
 
-function mergeNewLines(code: string) {
+/**
-  return getLines(code)
+ * Inlines code blocks in PowerShell scripts while preserving correct syntax.
-    .map((line) => line.trim())
+ * It removes unnecessary newlines and spaces around brackets,
-    .filter((line) => line.length > 0)
+ * inlining the code where possible.
-    .join('; ');
+ * This prevents syntax errors like "Unexpected token '}'" when inlining brackets.
+ */
+function mergeLinesWithBracketCodeBlocks(code: string): string {
+  return code
+    // Opening bracket: [whitespace] Opening bracket (newline)
+    .replace(/(?<=.*)\s*{[\r\n][\s\r\n]*/g, ' { ')
+    // Closing bracket: [whitespace] Closing bracket (newline) (continuation keyword)
+    .replace(/\s*}[\r\n][\s\r\n]*(?=elseif|else|catch|finally|until)/g, ' } ')
+    .replace(/(?<=do\s*{.*)[\r\n\s]*}[\r\n][\r\n\s]*(?=while)/g, ' } '); // Do-While
+}
+
+function mergeNewLines(code: string) {
+  const nonEmptyLines = splitTextIntoLines(code)
+    .map((line) => line.trim())
+    .filter((line) => line.length > 0);
+
+  return nonEmptyLines
+    .map((line, index) => {
+      const isLastLine = index === nonEmptyLines.length - 1;
+      if (isLastLine) {
+        return line;
+      }
+      return line.endsWith(';') ? line : `${line};`;
+    })
+    .join(' ');
 }

src/application/Parser/Executable/Script/Compiler/Expressions/Pipes/PipeFactory.ts

@@ -1,6 +1,6 @@
 import { InlinePowerShell } from './PipeDefinitions/InlinePowerShell';
 import { EscapeDoubleQuotes } from './PipeDefinitions/EscapeDoubleQuotes';
-import type { IPipe } from './IPipe';
+import type { Pipe } from './Pipe';
 
 const RegisteredPipes = [
   new EscapeDoubleQuotes(),
@@ -8,19 +8,19 @@ const RegisteredPipes = [
 ];
 
 export interface IPipeFactory {
-  get(pipeName: string): IPipe;
+  get(pipeName: string): Pipe;
 }
 
 export class PipeFactory implements IPipeFactory {
-  private readonly pipes = new Map<string, IPipe>();
+  private readonly pipes = new Map<string, Pipe>();
 
-  constructor(pipes: readonly IPipe[] = RegisteredPipes) {
+  constructor(pipes: readonly Pipe[] = RegisteredPipes) {
     for (const pipe of pipes) {
       this.registerPipe(pipe);
     }
   }
 
-  public get(pipeName: string): IPipe {
+  public get(pipeName: string): Pipe {
     validatePipeName(pipeName);
     const pipe = this.pipes.get(pipeName);
     if (!pipe) {
@@ -29,7 +29,7 @@ export class PipeFactory implements IPipeFactory {
     return pipe;
   }
 
-  private registerPipe(pipe: IPipe): void {
+  private registerPipe(pipe: Pipe): void {
     validatePipeName(pipe.name);
     if (this.pipes.has(pipe.name)) {
       throw new Error(`Pipe name must be unique: "${pipe.name}"`);

src/application/Parser/Executable/Script/Compiler/Function/Call/Argument/FunctionCallArgument.ts

@@ -22,7 +22,7 @@ export const createFunctionCallArgument: FunctionCallArgumentFactory = (
   utilities.validateParameterName(parameterName);
   utilities.typeValidator.assertNonEmptyString({
     value: argumentValue,
-    valueName: `Missing argument value for the parameter "${parameterName}".`,
+    valueName: `Function parameter '${parameterName}'`,
   });
   return {
     parameterName,

src/application/Parser/Executable/Script/Compiler/Function/Call/Compiler/CodeSegmentJoin/NewlineCodeSegmentMerger.ts

@@ -1,3 +1,4 @@
+import { filterEmptyStrings } from '@/application/Common/Text/FilterEmptyStrings';
 import type { CompiledCode } from '../CompiledCode';
 import type { CodeSegmentMerger } from './CodeSegmentMerger';
 
@@ -8,11 +9,9 @@ export class NewlineCodeSegmentMerger implements CodeSegmentMerger {
     }
     return {
       code: joinCodeParts(codeSegments.map((f) => f.code)),
-      revertCode: joinCodeParts(
+      revertCode: joinCodeParts(filterEmptyStrings(
-        codeSegments
+        codeSegments.map((f) => f.revertCode),
-          .map((f) => f.revertCode)
+      )),
-          .filter((code): code is string => Boolean(code)),
-      ),
     };
   }
 }

src/application/Parser/Executable/Script/Compiler/Function/Call/Compiler/SingleCall/Strategies/InlineFunctionCallCompiler.ts

@@ -3,6 +3,7 @@ import type { IExpressionsCompiler } from '@/application/Parser/Executable/Scrip
 import { FunctionBodyType, type ISharedFunction } from '@/application/Parser/Executable/Script/Compiler/Function/ISharedFunction';
 import type { FunctionCall } from '@/application/Parser/Executable/Script/Compiler/Function/Call/FunctionCall';
 import type { CompiledCode } from '@/application/Parser/Executable/Script/Compiler/Function/Call/Compiler/CompiledCode';
+import { indentText } from '@/application/Common/Text/IndentText';
 import type { SingleCallCompilerStrategy } from '../SingleCallCompilerStrategy';
 
 export class InlineFunctionCallCompiler implements SingleCallCompilerStrategy {
@@ -22,10 +23,12 @@ export class InlineFunctionCallCompiler implements SingleCallCompilerStrategy {
     if (calledFunction.body.type !== FunctionBodyType.Code) {
       throw new Error([
         'Unexpected function body type.',
-        `\tExpected: "${FunctionBodyType[FunctionBodyType.Code]}"`,
+        indentText([
-        `\tActual: "${FunctionBodyType[calledFunction.body.type]}"`,
+          `Expected: "${FunctionBodyType[FunctionBodyType.Code]}"`,
+          `Actual: "${FunctionBodyType[calledFunction.body.type]}"`,
+        ].join('\n')),
         'Function:',
-        `\t${JSON.stringify(callToFunction)}`,
+        indentText(JSON.stringify(callToFunction)),
       ].join('\n'));
     }
     const { code } = calledFunction.body;

src/application/Parser/Executable/Script/Compiler/Function/Call/FunctionCallsParser.ts

@@ -42,7 +42,7 @@ function getCallSequence(calls: FunctionCallsData, validator: TypeValidator): Fu
   if (isArray(calls)) {
     validator.assertNonEmptyCollection({
       value: calls,
-      valueName: 'function call sequence',
+      valueName: 'Function call sequence',
     });
     return calls as FunctionCallData[];
   }
@@ -56,7 +56,7 @@ function parseFunctionCall(
 ): FunctionCall {
   utilities.typeValidator.assertObject({
     value: call,
-    valueName: 'function call',
+    valueName: 'Function call',
     allowedProperties: ['function', 'parameters'],
   });
   const callArgs = parseArgs(call.parameters, utilities.createCallArgument);

src/application/Parser/Executable/Script/Compiler/Function/Shared/ParameterNameValidator.ts

@@ -13,7 +13,7 @@ export const validateParameterName = (
 ) => {
   typeValidator.assertNonEmptyString({
     value: parameterName,
-    valueName: 'parameter name',
+    valueName: 'Parameter name',
     rule: {
       expectedMatch: /^[0-9a-zA-Z]+$/,
       errorMessage: `parameter name must be alphanumeric but it was "${parameterName}".`,

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

@@ -2,13 +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';
@@ -22,14 +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();
@@ -38,7 +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;
@@ -48,7 +47,7 @@ export const parseSharedFunctions: SharedFunctionsParser = (
 const DefaultUtilities: SharedFunctionsParsingUtilities = {
   wrapError: wrapErrorWithAdditionalContext,
   parseParameter: parseFunctionParameter,
-  codeValidator: CodeValidator.instance,
+  codeValidator: validateCode,
   createParameterCollection: createFunctionParameterCollection,
   parseFunctionCalls,
 };
@@ -56,20 +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
@@ -77,17 +76,20 @@ function parseFunction(
   return createCallerFunction(name, parameters, calls);
 }
 
-function validateCode(
+function validateNonEmptyCode(
   data: CodeFunctionData,
-  syntax: ILanguageSyntax,
+  language: ScriptingLanguage,
-  validator: ICodeValidator,
+  validate: CodeValidator,
 ): void {
-  [data.code, data.revertCode]
+  filterEmptyStrings([data.code, data.revertCode])
-    .filter((code): code is string => Boolean(code))
     .forEach(
-      (code) => validator.throwIfInvalid(
+      (code) => validate(
         code,
-        [new NoEmptyLines(), new NoDuplicatedLines(syntax)],
+        language,
+        [
+          CodeValidationRule.NoEmptyLines,
+          CodeValidationRule.NoDuplicatedLines,
+        ],
       ),
     );
 }
@@ -204,9 +206,9 @@ function ensureNoDuplicateCode(functions: readonly FunctionData[]) {
   if (duplicateCodes.length > 0) {
     throw new Error(`duplicate "code" in functions: ${printList(duplicateCodes)}`);
   }
-  const duplicateRevertCodes = getDuplicates(callFunctions
+  const duplicateRevertCodes = getDuplicates(filterEmptyStrings(
-    .map((func) => func.revertCode)
+    callFunctions.map((func) => func.revertCode),
-    .filter((code): code is string => Boolean(code)));
+  ));
   if (duplicateRevertCodes.length > 0) {
     throw new Error(`duplicate "revertCode" in functions: ${printList(duplicateRevertCodes)}`);
   }

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

@@ -1,87 +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 { 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 {
-  [compiledCode.code, compiledCode.revertCode]
-    .filter((code): code is string => Boolean(code))
-    .map((code) => code as string)
-    .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

@@ -1,33 +1,32 @@
 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 { CollectionScript } from '@/domain/Executables/Script/CollectionScript';
 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';
 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({
@@ -37,10 +36,11 @@ export const parseScript: ScriptParser = (
   validateScript(data, validator);
   try {
     const script = scriptUtilities.createScript({
+      executableId: data.name, // Pseudo-ID for uniqueness until real ID support
       name: data.name,
       code: parseCode(
         data,
-        collectionUtilities,
+        collectionContext,
         scriptUtilities.codeValidator,
         scriptUtilities.createCode,
       ),
@@ -68,30 +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,
 ) {
-  [scriptCode.execute, scriptCode.revert]
+  filterEmptyStrings([scriptCode.execute, scriptCode.revert])
-    .filter((code): code is string => Boolean(code))
     .forEach(
-      (code) => validator.throwIfInvalid(
+      (code) => validate(
         code,
-        [new NoEmptyLines(), new NoDuplicatedLines(syntax)],
+        language,
+        [
+          CodeValidationRule.NoEmptyLines,
+          CodeValidationRule.NoDuplicatedLines,
+          CodeValidationRule.NoTooLongLines,
+        ],
       ),
     );
 }
@@ -102,7 +106,7 @@ function validateScript(
 ): asserts script is NonNullable<ScriptData> {
   validator.assertType((v) => v.assertObject<CallScriptData & CodeScriptData>({
     value: script,
-    valueName: script.name ?? 'script',
+    valueName: script.name ? `Script '${script.name}'` : 'Script',
     allowedProperties: [
       'name', 'recommend', 'code', 'revertCode', 'call', 'docs',
     ],
@@ -125,25 +129,17 @@ 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;
   readonly parseDocs: DocsParser;
 }
 
-export type ScriptFactory = (
-  ...parameters: ConstructorParameters<typeof CollectionScript>
-) => Script;
-
-const createScript: ScriptFactory = (...parameters) => {
-  return new CollectionScript(...parameters);
-};
-
 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 type { ICodeLine } from './ICodeLine';
+import { splitTextIntoLines } from '@/application/Common/Text/SplitTextIntoLines';
-import type { ICodeValidationRule, IInvalidCodeLine } from './ICodeValidationRule';
+import type { ScriptingLanguage } from '@/domain/ScriptingLanguage';
-import type { ICodeValidator } from './ICodeValidator';
+import { createValidationAnalyzers, type ValidationRuleAnalyzerFactory } from './ValidationRuleAnalyzerFactory';
+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);
+export const validateCode: CodeValidator = (
-    const invalidLines = rules.flatMap((rule) => rule.analyze(lines));
+  code,
-    if (invalidLines.length === 0) {
+  language,
-      return;
+  rules,
-    }
+  analyzerFactory = createValidationAnalyzers,
-    const errorText = `Errors with the code.\n${printLines(lines, invalidLines)}`;
+) => {
-    throw new Error(errorText);
+  const analyzers = analyzerFactory(rules);
+  if (!code) {
+    return;
   }
+  const lines = extractLines(code);
+  const invalidLines = analyzers.flatMap((analyze) => analyze(lines, language));
+  if (invalidLines.length === 0) {
+    return;
+  }
+  const errorText = `Errors with the code.\n${formatLines(lines, invalidLines)}`;
+  throw new Error(errorText);
+};
+
+function extractLines(code: string): CodeLine[] {
+  const lines = splitTextIntoLines(code);
+  return lines.map((lineText, lineIndex): CodeLine => ({
+    lineNumber: lineIndex + 1,
+    text: lineText,
+  }));
 }
 
-function extractLines(code: string): ICodeLine[] {
+function formatLines(
-  return code
+  lines: readonly CodeLine[],
-    .split(/\r\n|\r|\n/)
+  invalidLines: readonly InvalidCodeLine[],
-    .map((lineText, lineIndex): ICodeLine => ({
-      index: lineIndex + 1,
-      text: lineText,
-    }));
-}
-
-function printLines(
-  lines: readonly ICodeLine[],
-  invalidLines: readonly IInvalidCodeLine[],
 ): 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/application/Parser/ScriptingDefinition/ScriptingDefinitionParser.ts

@@ -37,7 +37,7 @@ function validateData(
 ): void {
   validator.assertObject({
     value: data,
-    valueName: 'scripting definition',
+    valueName: 'Scripting definition',
     allowedProperties: ['language', 'fileExtension', 'startCode', 'endCode'],
   });
 }

src/application/Repository/Repository.ts

@@ -1,17 +1,19 @@
-import type { IEntity } from '@/infrastructure/Entity/IEntity';
+import type { RepositoryEntity } from './RepositoryEntity';
 
-export interface ReadonlyRepository<TKey, TEntity extends IEntity<TKey>> {
+type EntityId = RepositoryEntity['id'];
+
+export interface ReadonlyRepository<TEntity extends RepositoryEntity> {
   readonly length: number;
   getItems(predicate?: (entity: TEntity) => boolean): readonly TEntity[];
-  getById(id: TKey): TEntity;
+  getById(id: EntityId): TEntity;
-  exists(id: TKey): boolean;
+  exists(id: EntityId): boolean;
 }
 
-export interface MutableRepository<TKey, TEntity extends IEntity<TKey>> {
+export interface MutableRepository<TEntity extends RepositoryEntity> {
   addItem(item: TEntity): void;
   addOrUpdateItem(item: TEntity): void;
-  removeItem(id: TKey): void;
+  removeItem(id: EntityId): void;
 }
 
-export interface Repository<TKey, TEntity extends IEntity<TKey>>
+export interface Repository<TEntity extends RepositoryEntity>
-  extends ReadonlyRepository<TKey, TEntity>, MutableRepository<TKey, TEntity> { }
+  extends ReadonlyRepository<TEntity>, MutableRepository<TEntity> { }

src/application/Repository/RepositoryEntity.ts

@@ -0,0 +1,6 @@
+/** Aggregate root */
+export type RepositoryEntityId = string;
+
+export interface RepositoryEntity {
+  readonly id: RepositoryEntityId;
+}

src/application/collections/.schema.yaml

@@ -69,6 +69,12 @@ definitions:
       - $ref: '#/definitions/CodeScript'
       - $ref: '#/definitions/CallScript'
 
+  RecommendationLevel:
+    oneOf:
+    - type: string
+      enum: [standard, strict]
+    - type: 'null'
+
   ScriptDefinition:
     type: object
     allOf:
@@ -78,8 +84,7 @@ definitions:
       name:
         type: string
       recommend:
-        type: string
+        $ref: '#/definitions/RecommendationLevel'
-        enum: [standard, strict]
 
   CodeScript:
     type: object

src/application/collections/macos.yaml

@@ -1800,7 +1800,7 @@ actions:
                             # References for spctl --master-disable
                                 - https://web.archive.org/web/20240523173608/https://www.manpagez.com/man/8/spctl/
                             # References for /var/db/SystemPolicy-prefs.plist
-                                - https://krypted.com/mac-security/manage-gatekeeper-from-the-command-line-in-mountain-lion/
+                                - https://web.archive.org/web/20240810103202/https://krypted.com/mac-security/manage-gatekeeper-from-the-command-line-in-mountain-lion/
                                 - https://community.jamf.com/t5/jamf-pro/users-can-t-change-password-greyed-out/m-p/54228
                         code: |-
                             os_major_ver=$(sw_vers -productVersion | awk -F "." '{print $1}')
@@ -1842,10 +1842,10 @@ actions:
                             fi
             -
                 name: Disable library validation entitlement (library signature validation)
-                docs:
+                docs: |-
-                    - https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_security_cs_disable-library-validation
+                    - [Disable Library Validation Entitlement | Apple Developer Documentation | developer.apple.com](https://archive.ph/2024.07.19-101811/https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_security_cs_disable-library-validation)
-                    - https://www.macenhance.com/docs/general/sip-library-validation.html
+                    - [Forbidden Commands to Speed Up macOS | www.naut.ca](https://web.archive.org/web/20240625020749/https://www.naut.ca/blog/2020/11/13/forbidden-commands-to-liberate-macos/)
-                    - https://www.naut.ca/blog/2020/11/13/forbidden-commands-to-liberate-macos/
+                    - [macEnhance | macEnhance.com](https://web.archive.org/web/20220622212008/https://www.macenhance.com/docs/general/sip-library-validation.html)
                 code: sudo defaults write /Library/Preferences/com.apple.security.libraryvalidation.plist 'DisableLibraryValidation' -bool true
                 revertCode: sudo defaults write /Library/Preferences/com.apple.security.libraryvalidation.plist 'DisableLibraryValidation' -bool false
             -

src/domain/Application.ts

@@ -1,6 +1,6 @@
 import { OperatingSystem } from './OperatingSystem';
 import type { IApplication } from './IApplication';
-import type { ICategoryCollection } from './ICategoryCollection';
+import type { ICategoryCollection } from './Collection/ICategoryCollection';
 import type { ProjectDetails } from './Project/ProjectDetails';
 
 export class Application implements IApplication {

src/domain/Collection/CategoryCollection.ts

@@ -1,11 +1,13 @@
 import { getEnumValues, assertInRange } from '@/application/Common/Enum';
-import { RecommendationLevel } from './Executables/Script/RecommendationLevel';
+import { RecommendationLevel } from '../Executables/Script/RecommendationLevel';
-import { OperatingSystem } from './OperatingSystem';
+import { OperatingSystem } from '../OperatingSystem';
-import type { IEntity } from '../infrastructure/Entity/IEntity';
+import { validateCategoryCollection } from './Validation/CompositeCategoryCollectionValidator';
-import type { Category } from './Executables/Category/Category';
+import type { ExecutableId } from '../Executables/Identifiable';
-import type { Script } from './Executables/Script/Script';
+import type { Category } from '../Executables/Category/Category';
-import type { IScriptingDefinition } from './IScriptingDefinition';
+import type { Script } from '../Executables/Script/Script';
+import type { IScriptingDefinition } from '../IScriptingDefinition';
 import type { ICategoryCollection } from './ICategoryCollection';
+import type { CategoryCollectionValidator } from './Validation/CategoryCollectionValidator';
 
 export class CategoryCollection implements ICategoryCollection {
   public readonly os: OperatingSystem;
@@ -22,22 +24,24 @@ export class CategoryCollection implements ICategoryCollection {
 
   constructor(
     parameters: CategoryCollectionInitParameters,
+    validate: CategoryCollectionValidator = validateCategoryCollection,
   ) {
     this.os = parameters.os;
     this.actions = parameters.actions;
     this.scripting = parameters.scripting;
 
     this.queryable = makeQueryable(this.actions);
-    assertInRange(this.os, OperatingSystem);
+    validate({
-    ensureValid(this.queryable);
+      allScripts: this.queryable.allScripts,
-    ensureNoDuplicates(this.queryable.allCategories);
+      allCategories: this.queryable.allCategories,
-    ensureNoDuplicates(this.queryable.allScripts);
+      operatingSystem: this.os,
+    });
   }
 
-  public getCategory(categoryId: number): Category {
+  public getCategory(executableId: ExecutableId): Category {
-    const category = this.queryable.allCategories.find((c) => c.id === categoryId);
+    const category = this.queryable.allCategories.find((c) => c.executableId === executableId);
     if (!category) {
-      throw new Error(`Missing category with ID: "${categoryId}"`);
+      throw new Error(`Missing category with ID: "${executableId}"`);
     }
     return category;
   }
@@ -48,10 +52,10 @@ export class CategoryCollection implements ICategoryCollection {
     return scripts ?? [];
   }
 
-  public getScript(scriptId: string): Script {
+  public getScript(executableId: ExecutableId): Script {
-    const script = this.queryable.allScripts.find((s) => s.id === scriptId);
+    const script = this.queryable.allScripts.find((s) => s.executableId === executableId);
     if (!script) {
-      throw new Error(`missing script: ${scriptId}`);
+      throw new Error(`Missing script: ${executableId}`);
     }
     return script;
   }
@@ -65,21 +69,6 @@ export class CategoryCollection implements ICategoryCollection {
   }
 }
 
-function ensureNoDuplicates<TKey>(entities: ReadonlyArray<IEntity<TKey>>) {
-  const isUniqueInArray = (id: TKey, index: number, array: readonly TKey[]) => array
-    .findIndex((otherId) => otherId === id) !== index;
-  const duplicatedIds = entities
-    .map((entity) => entity.id)
-    .filter((id, index, array) => !isUniqueInArray(id, index, array))
-    .filter(isUniqueInArray);
-  if (duplicatedIds.length > 0) {
-    const duplicatedIdsText = duplicatedIds.map((id) => `"${id}"`).join(',');
-    throw new Error(
-      `Duplicate entities are detected with following id(s): ${duplicatedIdsText}`,
-    );
-  }
-}
-
 export interface CategoryCollectionInitParameters {
   readonly os: OperatingSystem;
   readonly actions: ReadonlyArray<Category>;
@@ -92,35 +81,12 @@ interface QueryableCollection {
   readonly scriptsByLevel: Map<RecommendationLevel, readonly Script[]>;
 }
 
-function ensureValid(application: QueryableCollection) {
+function flattenCategoryHierarchy(
-  ensureValidCategories(application.allCategories);
-  ensureValidScripts(application.allScripts);
-}
-
-function ensureValidCategories(allCategories: readonly Category[]) {
-  if (!allCategories.length) {
-    throw new Error('must consist of at least one category');
-  }
-}
-
-function ensureValidScripts(allScripts: readonly Script[]) {
-  if (!allScripts.length) {
-    throw new Error('must consist of at least one script');
-  }
-  const missingRecommendationLevels = getEnumValues(RecommendationLevel)
-    .filter((level) => allScripts.every((script) => script.level !== level));
-  if (missingRecommendationLevels.length > 0) {
-    throw new Error('none of the scripts are recommended as'
-      + ` "${missingRecommendationLevels.map((level) => RecommendationLevel[level]).join(', "')}".`);
-  }
-}
-
-function flattenApplication(
   categories: ReadonlyArray<Category>,
 ): [Category[], Script[]] {
   const [subCategories, subScripts] = (categories || [])
     // Parse children
-    .map((category) => flattenApplication(category.subCategories))
+    .map((category) => flattenCategoryHierarchy(category.subcategories))
     // Flatten results
     .reduce(([previousCategories, previousScripts], [currentCategories, currentScripts]) => {
       return [
@@ -143,7 +109,7 @@ function flattenApplication(
 function makeQueryable(
   actions: ReadonlyArray<Category>,
 ): QueryableCollection {
-  const flattened = flattenApplication(actions);
+  const flattened = flattenCategoryHierarchy(actions);
   return {
     allCategories: flattened[0],
     allScripts: flattened[1],

src/domain/Collection/ICategoryCollection.ts

@@ -3,6 +3,7 @@ import { OperatingSystem } from '@/domain/OperatingSystem';
 import { RecommendationLevel } from '@/domain/Executables/Script/RecommendationLevel';
 import type { Script } from '@/domain/Executables/Script/Script';
 import type { Category } from '@/domain/Executables/Category/Category';
+import type { ExecutableId } from '../Executables/Identifiable';
 
 export interface ICategoryCollection {
   readonly scripting: IScriptingDefinition;
@@ -12,8 +13,8 @@ export interface ICategoryCollection {
   readonly actions: ReadonlyArray<Category>;
 
   getScriptsByLevel(level: RecommendationLevel): ReadonlyArray<Script>;
-  getCategory(categoryId: number): Category;
+  getCategory(categoryId: ExecutableId): Category;
-  getScript(scriptId: string): Script;
+  getScript(scriptId: ExecutableId): Script;
   getAllScripts(): ReadonlyArray<Script>;
   getAllCategories(): ReadonlyArray<Category>;
 }

src/domain/Collection/Validation/CategoryCollectionValidator.ts

@@ -0,0 +1,15 @@
+import type { Category } from '@/domain/Executables/Category/Category';
+import type { Script } from '@/domain/Executables/Script/Script';
+import type { OperatingSystem } from '@/domain/OperatingSystem';
+
+export interface CategoryCollectionValidationContext {
+  readonly allScripts: readonly Script[];
+  readonly allCategories: readonly Category[];
+  readonly operatingSystem: OperatingSystem;
+}
+
+export interface CategoryCollectionValidator {
+  (
+    context: CategoryCollectionValidationContext,
+  ): void;
+}

src/domain/Collection/Validation/CompositeCategoryCollectionValidator.ts

@@ -0,0 +1,33 @@
+import { ensurePresenceOfAtLeastOneScript } from './Rules/EnsurePresenceOfAtLeastOneScript';
+import { ensurePresenceOfAtLeastOneCategory } from './Rules/EnsurePresenceOfAtLeastOneCategory';
+import { ensureUniqueIdsAcrossExecutables } from './Rules/EnsureUniqueIdsAcrossExecutables';
+import { ensureKnownOperatingSystem } from './Rules/EnsureKnownOperatingSystem';
+import type { CategoryCollectionValidationContext, CategoryCollectionValidator } from './CategoryCollectionValidator';
+
+export type CompositeCategoryCollectionValidator = CategoryCollectionValidator & {
+  (
+    ...args: [
+      ...Parameters<CategoryCollectionValidator>,
+      (readonly CategoryCollectionValidator[])?,
+    ]
+  ): ReturnType<CategoryCollectionValidator>;
+};
+
+export const validateCategoryCollection: CompositeCategoryCollectionValidator = (
+  context: CategoryCollectionValidationContext,
+  validators: readonly CategoryCollectionValidator[] = DefaultValidators,
+) => {
+  if (!validators.length) {
+    throw new Error('No validators provided.');
+  }
+  for (const validate of validators) {
+    validate(context);
+  }
+};
+
+const DefaultValidators: readonly CategoryCollectionValidator[] = [
+  ensureKnownOperatingSystem,
+  ensurePresenceOfAtLeastOneScript,
+  ensurePresenceOfAtLeastOneCategory,
+  ensureUniqueIdsAcrossExecutables,
+];

src/domain/Collection/Validation/Rules/EnsureKnownOperatingSystem.ts

@@ -0,0 +1,9 @@
+import { assertInRange } from '@/application/Common/Enum';
+import { OperatingSystem } from '@/domain/OperatingSystem';
+import type { CategoryCollectionValidator } from '../CategoryCollectionValidator';
+
+export const ensureKnownOperatingSystem: CategoryCollectionValidator = (
+  context,
+) => {
+  assertInRange(context.operatingSystem, OperatingSystem);
+};

src/domain/Collection/Validation/Rules/EnsurePresenceOfAllRecommendationLevels.ts

@@ -0,0 +1,35 @@
+import { getEnumValues } from '@/application/Common/Enum';
+import { RecommendationLevel } from '@/domain/Executables/Script/RecommendationLevel';
+import type { Script } from '@/domain/Executables/Script/Script';
+import type { CategoryCollectionValidator } from '../CategoryCollectionValidator';
+
+export const ensurePresenceOfAllRecommendationLevels: CategoryCollectionValidator = (
+  context,
+) => {
+  const unrepresentedRecommendationLevels = getUnrepresentedRecommendationLevels(
+    context.allScripts,
+  );
+  if (unrepresentedRecommendationLevels.length === 0) {
+    return;
+  }
+  const formattedRecommendationLevels = unrepresentedRecommendationLevels
+    .map((level) => getDisplayName(level))
+    .join(', ');
+  throw new Error(`Missing recommendation levels: ${formattedRecommendationLevels}.`);
+};
+
+function getUnrepresentedRecommendationLevels(
+  scripts: readonly Script[],
+): (RecommendationLevel | undefined)[] {
+  const expectedLevels = [
+    undefined,
+    ...getEnumValues(RecommendationLevel),
+  ];
+  return expectedLevels.filter(
+    (level) => scripts.every((script) => script.level !== level),
+  );
+}
+
+function getDisplayName(level: RecommendationLevel | undefined): string {
+  return level === undefined ? 'None' : RecommendationLevel[level];
+}

src/domain/Collection/Validation/Rules/EnsurePresenceOfAtLeastOneCategory.ts

@@ -0,0 +1,9 @@
+import type { CategoryCollectionValidator } from '../CategoryCollectionValidator';
+
+export const ensurePresenceOfAtLeastOneCategory: CategoryCollectionValidator = (
+  context,
+) => {
+  if (!context.allCategories.length) {
+    throw new Error('Collection must have at least one category');
+  }
+};

src/domain/Collection/Validation/Rules/EnsurePresenceOfAtLeastOneScript.ts

@@ -0,0 +1,9 @@
+import type { CategoryCollectionValidator } from '../CategoryCollectionValidator';
+
+export const ensurePresenceOfAtLeastOneScript: CategoryCollectionValidator = (
+  context,
+) => {
+  if (!context.allScripts.length) {
+    throw new Error('Collection must have at least one script');
+  }
+};

src/domain/Collection/Validation/Rules/EnsureUniqueIdsAcrossExecutables.ts

@@ -0,0 +1,43 @@
+import type { Identifiable } from '@/domain/Executables/Identifiable';
+import type { CategoryCollectionValidator } from '../CategoryCollectionValidator';
+
+export const ensureUniqueIdsAcrossExecutables: CategoryCollectionValidator = (
+  context,
+) => {
+  const allExecutables: readonly Identifiable[] = [
+    ...context.allCategories,
+    ...context.allScripts,
+  ];
+  ensureNoDuplicateIds(allExecutables);
+};
+
+function ensureNoDuplicateIds(
+  executables: readonly Identifiable[],
+) {
+  const duplicateExecutables = getExecutablesWithDuplicateIds(executables);
+  if (duplicateExecutables.length === 0) {
+    return;
+  }
+  const formattedDuplicateIds = duplicateExecutables.map(
+    (executable) => `"${executable.executableId}"`,
+  ).join(', ');
+  throw new Error(`Duplicate executable IDs found: ${formattedDuplicateIds}`);
+}
+
+function getExecutablesWithDuplicateIds(
+  executables: readonly Identifiable[],
+): Identifiable[] {
+  return executables
+    .filter(
+      (executable, index, array) => {
+        const otherIndex = array.findIndex(
+          (otherExecutable) => haveIdenticalIds(executable, otherExecutable),
+        );
+        return otherIndex !== index;
+      },
+    );
+}
+
+function haveIdenticalIds(first: Identifiable, second: Identifiable): boolean {
+  return first.executableId === second.executableId;
+}

src/domain/Executables/Category/Category.ts

@@ -1,10 +1,9 @@
 import type { Script } from '../Script/Script';
 import type { Executable } from '../Executable';
 
-export interface Category extends Executable<number> {
+export interface Category extends Executable {
-  readonly id: number;
   readonly name: string;
-  readonly subCategories: ReadonlyArray<Category>;
+  readonly subcategories: ReadonlyArray<Category>;
   readonly scripts: ReadonlyArray<Script>;
   includes(script: Script): boolean;
   getAllScriptsRecursively(): ReadonlyArray<Script>;

src/domain/Executables/Category/CategoryFactory.ts

@@ -1,29 +1,51 @@
-import { BaseEntity } from '@/infrastructure/Entity/BaseEntity';
+import type { Category } from '@/domain/Executables/Category/Category';
-import type { Category } from './Category';
+import type { Script } from '@/domain/Executables/Script/Script';
-import type { Script } from '../Script/Script';
+import type { ExecutableId } from '../Identifiable';
 
-export class CollectionCategory extends BaseEntity<number> implements Category {
+export type CategoryFactory = (
-  private allSubScripts?: ReadonlyArray<Script> = undefined;
+  parameters: CategoryInitParameters,
+) => Category;
+
+export interface CategoryInitParameters {
+  readonly executableId: ExecutableId;
+  readonly name: string;
+  readonly docs: ReadonlyArray<string>;
+  readonly subcategories: ReadonlyArray<Category>;
+  readonly scripts: ReadonlyArray<Script>;
+}
+
+export const createCategory: CategoryFactory = (
+  parameters,
+) => {
+  return new CollectionCategory(parameters);
+};
+
+class CollectionCategory implements Category {
+  public readonly executableId: ExecutableId;
 
   public readonly name: string;
 
   public readonly docs: ReadonlyArray<string>;
 
-  public readonly subCategories: ReadonlyArray<Category>;
+  public readonly subcategories: ReadonlyArray<Category>;
 
   public readonly scripts: ReadonlyArray<Script>;
 
+  private allSubScripts?: ReadonlyArray<Script> = undefined;
+
   constructor(parameters: CategoryInitParameters) {
-    super(parameters.id);
     validateParameters(parameters);
+    this.executableId = parameters.executableId;
     this.name = parameters.name;
     this.docs = parameters.docs;
-    this.subCategories = parameters.subcategories;
+    this.subcategories = parameters.subcategories;
     this.scripts = parameters.scripts;
   }
 
   public includes(script: Script): boolean {
-    return this.getAllScriptsRecursively().some((childScript) => childScript.id === script.id);
+    return this
+      .getAllScriptsRecursively()
+      .some((childScript) => childScript.executableId === script.executableId);
   }
 
   public getAllScriptsRecursively(): readonly Script[] {
@@ -34,22 +56,17 @@ export class CollectionCategory extends BaseEntity<number> implements Category {
   }
 }
 
-export interface CategoryInitParameters {
-  readonly id: number;
-  readonly name: string;
-  readonly docs: ReadonlyArray<string>;
-  readonly subcategories: ReadonlyArray<Category>;
-  readonly scripts: ReadonlyArray<Script>;
-}
-
 function parseScriptsRecursively(category: Category): ReadonlyArray<Script> {
   return [
     ...category.scripts,
-    ...category.subCategories.flatMap((c) => c.getAllScriptsRecursively()),
+    ...category.subcategories.flatMap((c) => c.getAllScriptsRecursively()),
   ];
 }
 
 function validateParameters(parameters: CategoryInitParameters) {
+  if (!parameters.executableId) {
+    throw new Error('missing ID');
+  }
   if (!parameters.name) {
     throw new Error('missing name');
   }

src/domain/Executables/Executable.ts

@@ -1,6 +1,6 @@
-import type { IEntity } from '@/infrastructure/Entity/IEntity';
 import type { Documentable } from './Documentable';
+import type { Identifiable } from './Identifiable';
 
-export interface Executable<TExecutableKey>
+export interface Executable
-  extends Documentable, IEntity<TExecutableKey> {
+  extends Documentable, Identifiable {
 }

src/domain/Executables/Identifiable.ts

@@ -0,0 +1,5 @@
+export type ExecutableId = string;
+
+export interface Identifiable {
+  readonly executableId: ExecutableId;
+}

src/domain/Executables/Script/Script.ts

@@ -3,7 +3,7 @@ import type { Executable } from '../Executable';
 import type { Documentable } from '../Documentable';
 import type { ScriptCode } from './Code/ScriptCode';
 
-export interface Script extends Executable<string>, Documentable {
+export interface Script extends Executable, Documentable {
   readonly name: string;
   readonly level?: RecommendationLevel;
   readonly code: ScriptCode;

src/domain/Executables/Script/ScriptFactory.ts

@@ -1,9 +1,27 @@
-import { BaseEntity } from '@/infrastructure/Entity/BaseEntity';
 import { RecommendationLevel } from './RecommendationLevel';
-import type { Script } from './Script';
 import type { ScriptCode } from './Code/ScriptCode';
+import type { Script } from './Script';
+import type { ExecutableId } from '../Identifiable';
+
+export interface ScriptInitParameters {
+  readonly executableId: ExecutableId;
+  readonly name: string;
+  readonly code: ScriptCode;
+  readonly docs: ReadonlyArray<string>;
+  readonly level?: RecommendationLevel;
+}
+
+export type ScriptFactory = (
+  parameters: ScriptInitParameters,
+) => Script;
+
+export const createScript: ScriptFactory = (parameters) => {
+  return new CollectionScript(parameters);
+};
+
+class CollectionScript implements Script {
+  public readonly executableId: ExecutableId;
 
-export class CollectionScript extends BaseEntity<string> implements Script {
   public readonly name: string;
 
   public readonly code: ScriptCode;
@@ -13,7 +31,7 @@ export class CollectionScript extends BaseEntity<string> implements Script {
   public readonly level?: RecommendationLevel;
 
   constructor(parameters: ScriptInitParameters) {
-    super(parameters.name);
+    this.executableId = parameters.executableId;
     this.name = parameters.name;
     this.code = parameters.code;
     this.docs = parameters.docs;
@@ -26,13 +44,6 @@ export class CollectionScript extends BaseEntity<string> implements Script {
   }
 }
 
-export interface ScriptInitParameters {
-  readonly name: string;
-  readonly code: ScriptCode;
-  readonly docs: ReadonlyArray<string>;
-  readonly level?: RecommendationLevel;
-}
-
 function validateLevel(level?: RecommendationLevel) {
   if (level !== undefined && !(level in RecommendationLevel)) {
     throw new Error(`invalid level: ${level}`);

src/domain/IApplication.ts

@@ -1,4 +1,4 @@
-import type { ICategoryCollection } from './ICategoryCollection';
+import type { ICategoryCollection } from './Collection/ICategoryCollection';
 import type { ProjectDetails } from './Project/ProjectDetails';
 import type { OperatingSystem } from './OperatingSystem';
 

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,
   ) { }