Merge pull request #7 from a-bugaj/feat/return-values

feat: Return values from methods

Author: a-bugaj

.gitignore

@@ -2,4 +2,5 @@ node_modules
 package-lock.json
 dist
 coverage
-*.tgz
+*.tgz
+.idea

__tests__/pubSub.test.ts

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/ban-ts-comment */
 import PubSub, { PubSubInterface } from "../lib";
 
 // eslint-disable-next-line @typescript-eslint/no-empty-function
@@ -102,6 +103,54 @@ describe("PubSub -> Unsubscribe Method", () => {
         expect(eventsAfterUnsubscribe).toHaveLength(0);
     });
 
+    it("Should return false when a hashKey has not been passed", () => {
+        // given
+        const event = "unsubscribe.event";
+
+        // when
+        pubSub.subscribe(event, noop);
+        const eventsAfterSubscribe = pubSub.getAllSubscribers();
+        expect(eventsAfterSubscribe).toHaveLength(1);
+
+        // then
+        // @ts-ignore just for the tests
+        const output = pubSub.unsubscribe();
+        const eventsAfterUnsubscribe = pubSub.getAllSubscribers();
+
+        expect(output).toBe(false);
+        expect(eventsAfterUnsubscribe).toHaveLength(1);
+    });
+
+    it("Should return true when successfully unsubscribed", () => {
+        // given
+        const event = "unsubscribe.event";
+
+        // when
+        const hashKey = pubSub.subscribe(event, noop);
+
+        // then
+        const output = pubSub.unsubscribe(hashKey);
+        const eventsAfterUnsubscribe = pubSub.getAllSubscribers();
+
+        expect(output).toEqual(true);
+        expect(eventsAfterUnsubscribe).toHaveLength(0);
+    });
+
+    it("Should return false when someone pass a hashKey that does not exist in the subscription list", () => {
+        // given
+        const event = "unsubscribe.event";
+
+        // when
+        pubSub.subscribe(event, noop);
+
+        // then
+        const output = pubSub.unsubscribe("random-hash-key-that-not-exists");
+        const eventsAfterUnsubscribe = pubSub.getAllSubscribers();
+
+        expect(output).toEqual(false);
+        expect(eventsAfterUnsubscribe).toHaveLength(1);
+    });
+
     it("Should delete a specific event if there are two events with the same name in the subscribers list", () => {
         // given
         const event = "random.event";
@@ -162,6 +211,31 @@ describe("PubSub -> Publish method", () => {
         expect(callback).toHaveBeenCalledWith(data);
     });
 
+    it("Should return false when no one is subscribed to the published event", () => {
+        // given
+        const event = "nice.event!";
+
+        // when
+        const output = pubSub.publish(event);
+
+        // then
+        expect(output).toEqual(false);
+    });
+
+    it("Should return true when the event was published successfully", () => {
+        // given
+        const event = "nice.event!";
+        const callback = jest.fn();
+        pubSub.subscribe(event, callback);
+
+        // when
+        const output = pubSub.publish(event);
+
+        // then
+        expect(output).toEqual(true);
+        expect(callback).toHaveBeenCalledTimes(1);
+    });
+
     it("Should call callback from subscribe method (twice) after publishing the event twice.", () => {
         // given
         const event = "nice.event!";

lib/pubSub.ts

@@ -31,20 +31,31 @@ export class PubSub {
         return hashKey;
     };
 
-    unsubscribe = (hashKey: HashKey): void => {
-        if (!hashKey) return;
+    unsubscribe = (hashKey: HashKey): boolean => {
+        if (!hashKey) return false;
 
-        const events = this.subscribers.filter((subscriber) => subscriber.hashKey !== hashKey);
+        const isExists = this.subscribers.find(
+            ({ hashKey: subHashKey }) => subHashKey === hashKey
+        );
+
+        if (!isExists) return false;
 
+        const events = this.subscribers.filter((subscriber) => subscriber.hashKey !== hashKey);
         this.subscribers = events;
+
+        return true;
     };
 
-    publish = <E extends string, D = unknown>(event: E, data?: D): void => {
+    publish = <E extends string, D = unknown>(event: E, data?: D): boolean => {
         const events = this.subscribers.filter(({ eventName }) => eventName === event);
 
+        if (events.length === 0) return false;
+
         events.forEach((event) => {
             event.callback(data);
         });
+
+        return true;
     };
 
     getAllSubscribers = (): Subscribers[] => this.subscribers;