Fix dependabot issues

node_modules/ava/lib/plugin-support/shared-worker-loader.js

@@ -0,0 +1,252 @@
+const {EventEmitter, on} = require('events');
+const v8 = require('v8');
+const {workerData, parentPort} = require('worker_threads');
+const pkg = require('../../package.json');
+
+// Used to forward messages received over the `parentPort`. Every subscription
+// adds a listener, so do not enforce any maximums.
+const events = new EventEmitter().setMaxListeners(0);
+
+// Map of active test workers, used in receiveMessages() to get a reference to
+// the TestWorker instance, and relevant release functions.
+const activeTestWorkers = new Map();
+
+class TestWorker {
+	constructor(id, file) {
+		this.id = id;
+		this.file = file;
+	}
+
+	teardown(fn) {
+		let done = false;
+		const teardownFn = async () => {
+			if (done) {
+				return;
+			}
+
+			done = true;
+			if (activeTestWorkers.has(this.id)) {
+				activeTestWorkers.get(this.id).teardownFns.delete(teardownFn);
+			}
+
+			await fn();
+		};
+
+		activeTestWorkers.get(this.id).teardownFns.add(teardownFn);
+
+		return teardownFn;
+	}
+
+	publish(data) {
+		return publishMessage(this, data);
+	}
+
+	async * subscribe() {
+		yield * receiveMessages(this);
+	}
+}
+
+class ReceivedMessage {
+	constructor(testWorker, id, serializedData) {
+		this.testWorker = testWorker;
+		this.id = id;
+		this.data = v8.deserialize(new Uint8Array(serializedData));
+	}
+
+	reply(data) {
+		return publishMessage(this.testWorker, data, this.id);
+	}
+}
+
+// Ensure that, no matter how often it's received, we have a stable message
+// object.
+const messageCache = new WeakMap();
+
+async function * receiveMessages(fromTestWorker, replyTo) {
+	for await (const [message] of on(events, 'message')) {
+		if (fromTestWorker !== undefined) {
+			if (message.type === 'deregister-test-worker' && message.id === fromTestWorker.id) {
+				return;
+			}
+
+			if (message.type === 'message' && message.testWorkerId !== fromTestWorker.id) {
+				continue;
+			}
+		}
+
+		if (message.type !== 'message') {
+			continue;
+		}
+
+		if (replyTo === undefined && message.replyTo !== undefined) {
+			continue;
+		}
+
+		if (replyTo !== undefined && message.replyTo !== replyTo) {
+			continue;
+		}
+
+		const active = activeTestWorkers.get(message.testWorkerId);
+		// It is possible for a message to have been buffering for so long — perhaps
+		// due to the caller waiting before iterating to the next message — that the
+		// test worker has been deregistered. Ignore such messages.
+		//
+		// (This is really hard to write a test for, however!)
+		if (active === undefined) {
+			continue;
+		}
+
+		let received = messageCache.get(message);
+		if (received === undefined) {
+			received = new ReceivedMessage(active.instance, message.messageId, message.serializedData);
+			messageCache.set(message, received);
+		}
+
+		yield received;
+	}
+}
+
+let messageCounter = 0;
+const messageIdPrefix = `${workerData.id}/message`;
+const nextMessageId = () => `${messageIdPrefix}/${++messageCounter}`;
+
+function publishMessage(testWorker, data, replyTo) {
+	const id = nextMessageId();
+	parentPort.postMessage({
+		type: 'message',
+		messageId: id,
+		testWorkerId: testWorker.id,
+		serializedData: [...v8.serialize(data)],
+		replyTo
+	});
+
+	return {
+		id,
+		async * replies() {
+			yield * receiveMessages(testWorker, id);
+		}
+	};
+}
+
+function broadcastMessage(data) {
+	const id = nextMessageId();
+	parentPort.postMessage({
+		type: 'broadcast',
+		messageId: id,
+		serializedData: [...v8.serialize(data)]
+	});
+
+	return {
+		id,
+		async * replies() {
+			yield * receiveMessages(undefined, id);
+		}
+	};
+}
+
+async function loadFactory() {
+	try {
+		const mod = require(workerData.filename);
+		if (typeof mod === 'function') {
+			return mod;
+		}
+
+		return mod.default;
+	} catch (error) {
+		if (error && (error.code === 'ERR_REQUIRE_ESM' || (error.code === 'MODULE_NOT_FOUND' && workerData.filename.startsWith('file://')))) {
+			const {default: factory} = await import(workerData.filename); // eslint-disable-line node/no-unsupported-features/es-syntax
+			return factory;
+		}
+
+		throw error;
+	}
+}
+
+let signalAvailable = () => {
+	parentPort.postMessage({type: 'available'});
+	signalAvailable = () => {};
+};
+
+let fatal;
+loadFactory(workerData.filename).then(factory => {
+	if (typeof factory !== 'function') {
+		throw new TypeError(`Missing default factory function export for shared worker plugin at ${workerData.filename}`);
+	}
+
+	factory({
+		negotiateProtocol(supported) {
+			if (!supported.includes('experimental')) {
+				fatal = new Error(`This version of AVA (${pkg.version}) is not compatible with shared worker plugin at ${workerData.filename}`);
+				throw fatal;
+			}
+
+			const produceTestWorker = instance => events.emit('testWorker', instance);
+
+			parentPort.on('message', async message => {
+				if (message.type === 'register-test-worker') {
+					const {id, file} = message;
+					const instance = new TestWorker(id, file);
+
+					activeTestWorkers.set(id, {instance, teardownFns: new Set()});
+
+					produceTestWorker(instance);
+				}
+
+				if (message.type === 'deregister-test-worker') {
+					const {id} = message;
+					const {teardownFns} = activeTestWorkers.get(id);
+					activeTestWorkers.delete(id);
+
+					// Run possibly asynchronous release functions serially, in reverse
+					// order. Any error will crash the worker.
+					for await (const fn of [...teardownFns].reverse()) {
+						await fn();
+					}
+
+					parentPort.postMessage({
+						type: 'deregistered-test-worker',
+						id
+					});
+				}
+
+				// Wait for a turn of the event loop, to allow new subscriptions to be
+				// set up in response to the previous message.
+				setImmediate(() => events.emit('message', message));
+			});
+
+			return {
+				initialData: workerData.initialData,
+				protocol: 'experimental',
+
+				ready() {
+					signalAvailable();
+					return this;
+				},
+
+				broadcast(data) {
+					return broadcastMessage(data);
+				},
+
+				async * subscribe() {
+					yield * receiveMessages();
+				},
+
+				async * testWorkers() {
+					for await (const [worker] of on(events, 'testWorker')) {
+						yield worker;
+					}
+				}
+			};
+		}
+	});
+}).catch(error => {
+	if (fatal === undefined) {
+		fatal = error;
+	}
+}).finally(() => {
+	if (fatal !== undefined) {
+		process.nextTick(() => {
+			throw fatal;
+		});
+	}
+});