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/infrastructure/Events/EventSource.ts

@@ -1,27 +1,27 @@
 import { EventHandler, IEventSource, IEventSubscription } from './IEventSource';
 
 export class EventSource<T> implements IEventSource<T> {
-    private handlers = new Map<number, EventHandler<T>>();
+  private handlers = new Map<number, EventHandler<T>>();
 
-    public on(handler: EventHandler<T>): IEventSubscription {
-        const id = this.getUniqueEventHandlerId();
-        this.handlers.set(id, handler);
-        return {
-            unsubscribe: () => this.handlers.delete(id),
-        };
-    }
+  public on(handler: EventHandler<T>): IEventSubscription {
+    const id = this.getUniqueEventHandlerId();
+    this.handlers.set(id, handler);
+    return {
+      unsubscribe: () => this.handlers.delete(id),
+    };
+  }
 
-    public notify(data: T) {
-        for (const handler of Array.from(this.handlers.values())) {
-            handler(data);
-        }
+  public notify(data: T) {
+    for (const handler of Array.from(this.handlers.values())) {
+      handler(data);
     }
+  }
 
-    private getUniqueEventHandlerId(): number {
-        const id = Math.random();
-        if (this.handlers.has(id)) {
-            return this.getUniqueEventHandlerId();
-        }
-        return id;
+  private getUniqueEventHandlerId(): number {
+    const id = Math.random();
+    if (this.handlers.has(id)) {
+      return this.getUniqueEventHandlerId();
     }
+    return id;
+  }
 }

src/infrastructure/Events/EventSubscriptionCollection.ts

@@ -1,12 +1,14 @@
 import { IEventSubscription } from './IEventSource';
 
 export class EventSubscriptionCollection {
-    private readonly subscriptions = new Array<IEventSubscription>();
-    public register(...subscriptions: IEventSubscription[]) {
-        this.subscriptions.push(...subscriptions);
-    }
-    public unsubscribeAll() {
-        this.subscriptions.forEach((listener) => listener.unsubscribe());
-        this.subscriptions.splice(0, this.subscriptions.length);
-    }
+  private readonly subscriptions = new Array<IEventSubscription>();
+
+  public register(...subscriptions: IEventSubscription[]) {
+    this.subscriptions.push(...subscriptions);
+  }
+
+  public unsubscribeAll() {
+    this.subscriptions.forEach((listener) => listener.unsubscribe());
+    this.subscriptions.splice(0, this.subscriptions.length);
+  }
 }

src/infrastructure/Events/IEventSource.ts

@@ -1,11 +1,9 @@
 export interface IEventSource<T> {
-    on(handler: EventHandler<T>): IEventSubscription;
+  on(handler: EventHandler<T>): IEventSubscription;
 }
 
 export interface IEventSubscription {
-    unsubscribe(): void;
+  unsubscribe(): void;
 }
 
 export type EventHandler<T> = (data: T) => void;
-
-