Typescript Capstone Project

index.ts

@@ -0,0 +1,156 @@
+type RequestType = {
+  method: string;
+  host: string;
+  path: string;
+  body?: User;
+  params?: {
+      [key: string]: string;
+  }
+}
+
+type ObserverHandlers = {
+    next: (value: RequestType) => void;
+    error: (error: Error) => void;
+    complete: () => void;
+}
+
+class Observer {
+    private handlers: ObserverHandlers;
+    private isUnsubscribed: boolean;
+    _unsubscribe: () => void;
+
+    constructor(handlers: ObserverHandlers) {
+      this.handlers = handlers;
+      this.isUnsubscribed = false;
+    }
+
+    next(value: RequestType) {
+      if (this.handlers.next && !this.isUnsubscribed) {
+        this.handlers.next(value);
+      }
+    }
+
+    error(error: Error) {
+      if (!this.isUnsubscribed) {
+        if (this.handlers.error) {
+          this.handlers.error(error);
+        }
+
+        this.unsubscribe();
+      }
+    }
+
+    complete() {
+      if (!this.isUnsubscribed) {
+        if (this.handlers.complete) {
+          this.handlers.complete();
+        }
+
+        this.unsubscribe();
+      }
+    }
+
+    unsubscribe() {
+      this.isUnsubscribed = true;
+
+      if (this._unsubscribe) {
+        this._unsubscribe();
+      }
+    }
+}
+
+class Observable {
+    private _subscribe: (observer: Observer) => () => void;
+
+    constructor(subscribe: (observer: Observer) => () => void) {
+        this._subscribe = subscribe;
+    }
+
+    static from(values: RequestType[]) {
+        return new Observable((observer: Observer) => {
+            values.forEach((value: RequestType) => observer.next(value));
+
+            observer.complete();
+
+            return () => {
+                console.log('unsubscribed');
+            };
+        });
+    }
+
+    subscribe(obs: ObserverHandlers) {
+        const observer = new Observer(obs);
+
+        observer._unsubscribe = this._subscribe(observer);
+
+        return ({
+            unsubscribe() {
+                observer.unsubscribe();
+            }
+        });
+    }
+}
+
+const HTTP_POST_METHOD = 'POST';
+const HTTP_GET_METHOD = 'GET';
+
+const HTTP_STATUS_OK = 200;
+const HTTP_STATUS_INTERNAL_SERVER_ERROR = 500;
+
+type User =  {
+    name: string;
+    age: number;
+    roles: string[];
+    createdAt: Date;
+    isDeleated: boolean;
+}
+
+const userMock: User = {
+    name: 'User Name',
+    age: 26,
+    roles: [
+        'user',
+        'admin'
+    ],
+    createdAt: new Date(),
+    isDeleated: false,
+};
+
+const requestsMock: RequestType[] = [
+    {
+        method: HTTP_POST_METHOD,
+        host: 'service.example',
+        path: 'user',
+        body: userMock,
+        params: {},
+    },
+    {
+        method: HTTP_GET_METHOD,
+        host: 'service.example',
+        path: 'user',
+        params: {
+        id: '3f5h67s4s'
+        },
+    }
+];
+
+const handleRequest = (request: RequestType) => {
+    // handling of request
+    return {status: HTTP_STATUS_OK};
+};
+const handleError = (error: Error) => {
+    // handling of error
+    return {status: HTTP_STATUS_INTERNAL_SERVER_ERROR};
+};
+
+const handleComplete = () => console.log('complete');
+
+const requests$ = Observable.from(requestsMock);
+
+const subscription = requests$.subscribe({
+    next: handleRequest,
+    error: handleError,
+    complete: handleComplete
+});
+
+subscription.unsubscribe();