Fix memory leak caused by shared abort signals (#683)

Co-authored-by: Seth Holladay <[email protected]>

Author: sebinsua

package.json

@@ -67,6 +67,7 @@
 		"delay": "^6.0.0",
 		"expect-type": "^0.19.0",
 		"express": "^4.18.2",
+		"jest-leak-detector": "^29.7.0",
 		"pify": "^6.1.0",
 		"playwright": "^1.45.3",
 		"raw-body": "^2.5.2",

source/core/Ky.ts

@@ -168,16 +168,9 @@ export class Ky {
 		}
 
 		if (supportsAbortController) {
-			this.abortController = new globalThis.AbortController();
 			const originalSignal = this._options.signal ?? (this._input as Request).signal;
-			if (originalSignal?.aborted) {
-				this.abortController.abort(originalSignal?.reason);
-			}
-
-			originalSignal?.addEventListener('abort', () => {
-				this.abortController!.abort(originalSignal.reason);
-			});
-			this._options.signal = this.abortController.signal;
+			this.abortController = new globalThis.AbortController();
+			this._options.signal = originalSignal ? AbortSignal.any([originalSignal, this.abortController.signal]) : this.abortController.signal;
 		}
 
 		if (supportsRequestStreams) {

test/memory-leak.ts

@@ -0,0 +1,36 @@
+import test from 'ava';
+import _LeakDetector from 'jest-leak-detector';
+import ky, {type KyInstance} from '../source/index.js';
+import {createHttpTestServer} from './helpers/create-http-test-server.js';
+
+const LeakDetector = _LeakDetector.default as typeof _LeakDetector;
+
+test('shared abort signal must not cause memory leak of input', async t => {
+	const server = await createHttpTestServer();
+	server.get('/', (_request, response) => {
+		response.end('ok');
+	});
+
+	async function isKyLeaking(api: KyInstance) {
+		let url: URL | undefined = new URL(
+			`${server.url.toString()}?id=${Math.random()}`,
+		);
+		const detector = new LeakDetector(url);
+
+		await api.get(url);
+
+		url = undefined;
+
+		return detector.isLeaking();
+	}
+
+	const abortController = new AbortController();
+
+	try {
+		t.false(await isKyLeaking(ky.extend({})));
+		t.false(await isKyLeaking(ky.extend({signal: abortController.signal})));
+	} finally {
+		abortController.abort();
+		await server.close();
+	}
+});