Refactor code to comply with ESLint rules

Major refactoring using ESLint with rules from AirBnb and Vue.

Enable most of the ESLint rules and do necessary linting in the code.
Also add more information for rules that are disabled to describe what
they are and why they are disabled.

Allow logging (`console.log`) in test files, and in development mode
(e.g. when working with `npm run serve`), but disable it when
environment is production (as pre-configured by Vue). Also add flag
(`--mode production`) in `lint:eslint` command so production linting is
executed earlier in lifecycle.

Disable rules that requires a separate work. Such as ESLint rules that
are broken in TypeScript: no-useless-constructor (eslint/eslint#14118)
and no-shadow (eslint/eslint#13014).

src/application/Environment/Environment.ts

@@ -1,83 +1,89 @@
+import { OperatingSystem } from '@/domain/OperatingSystem';
 import { BrowserOsDetector } from './BrowserOs/BrowserOsDetector';
 import { IBrowserOsDetector } from './BrowserOs/IBrowserOsDetector';
 import { IEnvironment } from './IEnvironment';
-import { OperatingSystem } from '@/domain/OperatingSystem';
 
-interface IEnvironmentVariables {
-    readonly window: Window & typeof globalThis;
-    readonly process: NodeJS.Process;
-    readonly navigator: Navigator;
+export interface IEnvironmentVariables {
+  readonly window: Window & typeof globalThis;
+  readonly process: NodeJS.Process;
+  readonly navigator: Navigator;
 }
 
 export class Environment implements IEnvironment {
-    public static readonly CurrentEnvironment: IEnvironment = new Environment({
-        window,
-        process: typeof process !== 'undefined' ? process /* electron only */ : undefined,
-        navigator,
-    });
-    public readonly isDesktop: boolean;
-    public readonly os: OperatingSystem;
-    protected constructor(
-      variables: IEnvironmentVariables,
-      browserOsDetector: IBrowserOsDetector = new BrowserOsDetector()) {
-        if (!variables) {
-            throw new Error('variables is null or empty');
-        }
-        this.isDesktop = isDesktop(variables);
-        if (this.isDesktop) {
-            this.os = getDesktopOsType(getProcessPlatform(variables));
-        } else {
-            const userAgent = getUserAgent(variables);
-            this.os = !userAgent ? undefined : browserOsDetector.detect(userAgent);
-        }
+  public static readonly CurrentEnvironment: IEnvironment = new Environment({
+    window,
+    process: typeof process !== 'undefined' ? process /* electron only */ : undefined,
+    navigator,
+  });
+
+  public readonly isDesktop: boolean;
+
+  public readonly os: OperatingSystem;
+
+  protected constructor(
+    variables: IEnvironmentVariables,
+    browserOsDetector: IBrowserOsDetector = new BrowserOsDetector(),
+  ) {
+    if (!variables) {
+      throw new Error('variables is null or empty');
     }
+    this.isDesktop = isDesktop(variables);
+    if (this.isDesktop) {
+      this.os = getDesktopOsType(getProcessPlatform(variables));
+    } else {
+      const userAgent = getUserAgent(variables);
+      this.os = !userAgent ? undefined : browserOsDetector.detect(userAgent);
+    }
+  }
 }
 
 function getUserAgent(variables: IEnvironmentVariables): string {
-    if (!variables.window || !variables.window.navigator) {
-        return undefined;
-    }
-    return variables.window.navigator.userAgent;
+  if (!variables.window || !variables.window.navigator) {
+    return undefined;
+  }
+  return variables.window.navigator.userAgent;
 }
 
 function getProcessPlatform(variables: IEnvironmentVariables): string {
-    if (!variables.process || !variables.process.platform) {
-        return undefined;
-    }
-    return variables.process.platform;
+  if (!variables.process || !variables.process.platform) {
+    return undefined;
+  }
+  return variables.process.platform;
 }
 
 function getDesktopOsType(processPlatform: string): OperatingSystem | undefined {
-    // https://nodejs.org/api/process.html#process_process_platform
-    if (processPlatform === 'darwin') {
-        return OperatingSystem.macOS;
-    } else if (processPlatform === 'win32') {
-        return OperatingSystem.Windows;
-    } else if (processPlatform === 'linux') {
-        return OperatingSystem.Linux;
-    }
-    return undefined;
+  // https://nodejs.org/api/process.html#process_process_platform
+  switch (processPlatform) {
+    case 'darwin':
+      return OperatingSystem.macOS;
+    case 'win32':
+      return OperatingSystem.Windows;
+    case 'linux':
+      return OperatingSystem.Linux;
+    default:
+      return undefined;
+  }
 }
 
 function isDesktop(variables: IEnvironmentVariables): boolean {
-    // More: https://github.com/electron/electron/issues/2288
-    // Renderer process
-    if (variables.window
-        && variables.window.process
-        && variables.window.process.type === 'renderer') {
-        return true;
-    }
-    // Main process
-    if (variables.process
-        && variables.process.versions
-        && Boolean(variables.process.versions.electron)) {
-        return true;
-    }
-    // Detect the user agent when the `nodeIntegration` option is set to true
-    if (variables.navigator
-        && variables.navigator.userAgent
-        && variables.navigator.userAgent.includes('Electron')) {
-        return true;
-    }
-    return false;
+  // More: https://github.com/electron/electron/issues/2288
+  // Renderer process
+  if (variables.window
+    && variables.window.process
+    && variables.window.process.type === 'renderer') {
+    return true;
+  }
+  // Main process
+  if (variables.process
+    && variables.process.versions
+    && Boolean(variables.process.versions.electron)) {
+    return true;
+  }
+  // Detect the user agent when the `nodeIntegration` option is set to true
+  if (variables.navigator
+    && variables.navigator.userAgent
+    && variables.navigator.userAgent.includes('Electron')) {
+    return true;
+  }
+  return false;
 }