Alternative AbortController support (#54)

src/index.mjs

@@ -34,6 +34,14 @@ export default function(url, options) {
 			resolve(response());
 		};
 
+		if (options.signal) {
+			options.signal.addEventListener('abort', request.abort.bind(request));
+		}
+
+		request.onabort = () => {
+			reject(new DOMException('The user aborted a request.'));
+		};
+
 		request.onerror = reject;
 
 		request.withCredentials = options.credentials=='include';

test/index.js

@@ -1,6 +1,26 @@
+import { EventEmitter } from 'events';
 import fetch from '../src/index.mjs';
 import fetchDist from '..';
 
+// node does not have abort and signal classes
+class AbortSignal extends EventEmitter {
+	constructor() {
+		super();
+		this.addEventListener = jest.fn((type, callback) => {
+			this.on(type, callback);
+		});
+	}
+}
+
+class AbortController {
+	constructor() {
+		this.signal = new AbortSignal();
+	}
+	abort() {
+		this.signal.emit('abort');
+	}
+}
+
 describe('unfetch', () => {
 	it('should be a function', () => {
 		expect(fetch).toEqual(expect.any(Function));
@@ -80,5 +100,43 @@ describe('unfetch', () => {
 
 			return p;
 		});
+
+		it('respects abort signal', () => {
+			let xhrs = [];
+			global.XMLHttpRequest = jest.fn(() => {
+				let xhr = {
+					setRequestHeader: jest.fn(),
+					getAllResponseHeaders: jest.fn().mockReturnValue(''),
+					open: jest.fn(),
+					send: jest.fn(),
+					status: 0,
+					statusText: '',
+					responseText: '',
+					responseURL: '',
+					onabort: () => {},
+					abort: jest.fn(() => xhr.onabort())
+				};
+				xhrs.push(xhr);
+				return xhr;
+			});
+
+			const controller = new AbortController();
+			const p1 = fetch('/foo', { signal: controller.signal });
+			const p2 = fetch('/bar', { signal: controller.signal });
+
+			expect(controller.signal.addEventListener).toHaveBeenCalledTimes(2);
+			expect(controller.signal.addEventListener).toHaveBeenNthCalledWith(1, 'abort', expect.any(Function));
+			expect(controller.signal.addEventListener).toHaveBeenNthCalledWith(2, 'abort', expect.any(Function));
+
+			controller.abort();
+
+			expect(p1).rejects.toThrow(/abort/i);
+			expect(p2).rejects.toThrow(/abort/i);
+
+			expect(xhrs[0].abort).toHaveBeenCalledTimes(1);
+			expect(xhrs[1].abort).toHaveBeenCalledTimes(1);
+
+			return Promise.all([p1.catch(() => {}), p2.catch(() => {})]);
+		});
 	});
 });