Merge pull request #10 from DuncanMcPherson/test-subscription-counter

add test subscription counter

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ez-budgets/karma-test-utils",
-  "version": "0.1.6",
+  "version": "0.1.7",
   "description": "",
   "main": "dist/index.js",
   "files": [

readme.md

@@ -2,4 +2,4 @@
 
 ![Tests](https://github.com/duncanmcpherson/karma-test-utils/actions/workflows/test.yml/badge.svg)
 ![Build](https://github.com/duncanmcpherson/karma-test-utils/actions/workflows/merge.yml/badge.svg)
-[![codecov](https://codecov.io/gh/DuncanMcPherson/karma-test-utils/graph/badge.svg?token=B7FL6TPHO8)](https://codecov.io/gh/DuncanMcPherson/karma-test-utils)
+[![codecov](https://codecov.io/gh/DuncanMcPherson/karma-test-utils/graph/badge.svg?token=7ANvQV0UIg)](https://codecov.io/gh/DuncanMcPherson/karma-test-utils)

spec/test-subscription-counter.spec.ts

@@ -0,0 +1,31 @@
+import { TestSubscriptionCounter } from '../src';
+import { BehaviorSubject } from "rxjs";
+
+describe("TestSubscriptionCounter", () => {
+	let counter: TestSubscriptionCounter<number>;
+	let observable: BehaviorSubject<number>
+
+	beforeEach(() => {
+		observable = new BehaviorSubject<number>(0);
+		counter = new TestSubscriptionCounter<number>(observable);
+	});
+
+	describe("countedObservable$", () => {
+		it("should return a counted observable", () => {
+			expect(counter.countedObservable$).toBeTruthy();
+			const tempNumber = Math.floor(Math.random() * 10);
+			observable.next(tempNumber);
+			const subscription = counter.countedObservable$.subscribe((value) => {
+				expect(value).toEqual(tempNumber)
+			});
+			expect(counter.activeSubscriptionCount).toEqual(1);
+			expect(counter.lifetimeSubscriptionCount).toEqual(1);
+			expect(counter.allSubscriptionsFinalized).toEqual(false);
+			expect(counter.hadSubscribers).toEqual(true);
+			expect(counter.hasSubscribers).toEqual(true);
+			subscription.unsubscribe();
+			expect(counter.activeSubscriptionCount).toEqual(0);
+			expect(counter.allSubscriptionsFinalized).toEqual(true);
+		})
+	})
+})

src/index.ts

@@ -1,7 +1,3 @@
 export { IMockClassOptions } from "./autoMocker";
-export {
-	readObservableErrorSynchronously,
-	readObservableSynchronouslyAfterAction,
-	readObservableSynchronously,
-	readObservableCompletionSynchronously
-} from './read-observable-synchronously';
+export { readObservableSynchronously, readObservableCompletionSynchronously, readObservableErrorSynchronously, readObservableSynchronouslyAfterAction } from './read-observable-synchronously';
+export { TestSubscriptionCounter } from './test-subscription-counter';

src/test-subscription-counter.ts

@@ -0,0 +1,39 @@
+import { Observable, finalize, Subscriber } from 'rxjs';
+
+export class TestSubscriptionCounter<T> {
+	private _lifetimeSubscriptionCount: number = 0;
+	private _activeSubscriptionCount: number = 0;
+
+	public readonly countedObservable$: Observable<T> = new Observable<T>((observer: Subscriber<T>) => {
+		this._lifetimeSubscriptionCount++;
+		this._activeSubscriptionCount++;
+
+		const subscription = this.observable$
+			.pipe(finalize(() => this._activeSubscriptionCount--))
+			.subscribe(observer);
+
+		return () => subscription.unsubscribe();
+	});
+
+	constructor(private readonly observable$: Observable<T>) {}
+
+	public get lifetimeSubscriptionCount(): number {
+        return this._lifetimeSubscriptionCount;
+    }
+
+    public get activeSubscriptionCount(): number {
+        return this._activeSubscriptionCount;
+    }
+
+	public get hadSubscribers(): boolean {
+		return this.lifetimeSubscriptionCount > 0;
+	}
+
+	public get hasSubscribers(): boolean {
+		return this.activeSubscriptionCount > 0;
+	}
+
+	public get allSubscriptionsFinalized(): boolean {
+		return this.activeSubscriptionCount === 0;
+	}
+}