Add request cancellation support

developit#47

Author: melwyn95

src/index.js

@@ -29,6 +29,7 @@
  * @property {Array<(body: any, headers?: RequestHeaders) => any?>} [transformRequest] An array of transformations to apply to the outgoing request
  * @property {string} [baseURL] a base URL from which to resolve all URLs
  * @property {typeof window.fetch} [fetch] Custom window.fetch implementation
+ * @property {AbortSignal} [cancelToken] signal returned by AbortController
  * @property {any} [data]
  */
 
@@ -64,6 +65,16 @@
  * @type {<T=any>(url: string, body?: any, config?: Options) => Promise<Response<T>>}
  */
 
+/**
+ * @typedef CancelToken
+ * @type {{ (executor: Function): AbortSignal; source(): { token: AbortSignal; cancel: () => void; }; }}
+ */
+
+/**
+ * @typedef CancelTokenSourceMethod
+ * @type {() => { token: AbortSignal, cancel: () => void }}
+ */
+
 /**
  * @public
  * @param {Options} [defaults = {}]
@@ -138,6 +149,37 @@ function create(defaults) {
 		return out;
 	}
 
+	/**
+	 * CancelToken
+	 * @private
+	 * @param {Function} executor
+	 * @returns {AbortSignal}
+	 */
+	function CancelToken(executor) {
+		if (typeof executor !== 'function') {
+			throw new TypeError('executor must be a function.');
+		}
+
+		const ac = new AbortController();
+		executor(ac.abort.bind(ac));
+
+		return ac.signal;
+	}
+
+	/**
+	 * @private
+	 * @type {CancelTokenSourceMethod}
+	 * @returns
+	 */
+	CancelToken.source = () => {
+		const ac = new AbortController();
+
+		return {
+			token: ac.signal,
+			cancel: ac.abort.bind(ac)
+		};
+	};
+
 	/**
 	 * Issues a request.
 	 * @public
@@ -199,7 +241,8 @@ function create(defaults) {
 			method: (_method || options.method || 'get').toUpperCase(),
 			body: data,
 			headers: deepMerge(options.headers, customHeaders, true),
-			credentials: options.withCredentials ? 'include' : _undefined
+			credentials: options.withCredentials ? 'include' : _undefined,
+			signal: options.cancelToken
 		}).then((res) => {
 			for (const i in res) {
 				if (typeof res[i] != 'function') response[i] = res[i];
@@ -226,9 +269,16 @@ function create(defaults) {
 
 	/**
 	 * @public
-	 * @type {AbortController}
+	 * @type {CancelToken}
+	 */
+	redaxios.CancelToken = CancelToken;
+
+	/**
+	 * @public
+	 * @param {DOMError} e
+	 * @returns {boolean}
 	 */
-	redaxios.CancelToken = /** @type {any} */ (typeof AbortController == 'function' ? AbortController : Object);
+	redaxios.isCancel = (e) => e.name === 'AbortError';
 
 	/**
 	 * @public

test/index.test.js

@@ -336,4 +336,53 @@ describe('redaxios', () => {
 			expect(result).toEqual('hello world');
 		});
 	});
+
+	describe('Request cancellation using options.cancelToken', () => {
+		it('should cancel a request when cancelToken is passed as source.token', async () => {
+			const CancelToken = axios.CancelToken;
+			const source = CancelToken.source();
+
+			const axiosGet = axios.get(jsonExample, {
+				cancelToken: source.token
+			});
+			source.cancel();
+
+			const spy = jasmine.createSpy();
+			await axiosGet.catch(spy);
+
+			expect(spy).toHaveBeenCalledTimes(1);
+			expect(spy).toHaveBeenCalledWith(
+				jasmine.objectContaining({ code: 20, message: 'The user aborted a request.', name: 'AbortError' })
+			);
+		});
+
+		it('should cancel a request when cancelToken is passed as instance CreateToken', async () => {
+			const CancelToken = axios.CancelToken;
+			let cancel;
+
+			const axiosGet = axios.get(jsonExample, {
+				cancelToken: new CancelToken(function executor(c) {
+					cancel = c;
+				})
+			});
+
+			cancel();
+
+			const spy = jasmine.createSpy();
+			let error;
+			await axiosGet.catch((e) => ((error = e), spy(e)));
+
+			expect(axios.isCancel(error)).toBeTruthy(true);
+			expect(spy).toHaveBeenCalledTimes(1);
+			expect(spy).toHaveBeenCalledWith(
+				jasmine.objectContaining({ code: 20, message: 'The user aborted a request.', name: 'AbortError' })
+			);
+		});
+
+		it('should throw TypeError if no executor function is passed to CancelToken constructor', () => {
+			const CancelToken = axios.CancelToken;
+
+			expect(() => new CancelToken()).toThrowError('executor must be a function.');
+		});
+	});
 });