test(core): Add integration test for JS task runner (#12804)

Co-authored-by: Iván Ovejero <ivov.src@gmail.com>

packages/cli/test/integration/task-runners/task-runner-process.test.ts

@@ -0,0 +1,117 @@
+import { Container } from '@n8n/di';
+
+import { TaskBroker } from '@/task-runners/task-broker.service';
+import { TaskRunnerProcess } from '@/task-runners/task-runner-process';
+import { TaskRunnerProcessRestartLoopDetector } from '@/task-runners/task-runner-process-restart-loop-detector';
+import { TaskRunnerWsServer } from '@/task-runners/task-runner-ws-server';
+import { retryUntil } from '@test-integration/retry-until';
+import { setupBrokerTestServer } from '@test-integration/utils/task-broker-test-server';
+
+describe('TaskRunnerProcess', () => {
+	const { config, server: taskRunnerServer } = setupBrokerTestServer({
+		mode: 'internal',
+	});
+	const runnerProcess = Container.get(TaskRunnerProcess);
+	const taskBroker = Container.get(TaskBroker);
+	const taskRunnerService = Container.get(TaskRunnerWsServer);
+
+	beforeAll(async () => {
+		await taskRunnerServer.start();
+		// Set the port to the actually used port
+		config.port = taskRunnerServer.port;
+	});
+
+	afterAll(async () => {
+		await taskRunnerServer.stop();
+	});
+
+	afterEach(async () => {
+		await runnerProcess.stop();
+	});
+
+	const getNumConnectedRunners = () => taskRunnerService.runnerConnections.size;
+	const getNumRegisteredRunners = () => taskBroker.getKnownRunners().size;
+
+	it('should start and connect the task runner', async () => {
+		// Act
+		await runnerProcess.start();
+
+		// Assert
+		expect(runnerProcess.isRunning).toBeTruthy();
+
+		// Wait until the runner has connected
+		await retryUntil(() => expect(getNumConnectedRunners()).toBe(1));
+		expect(getNumRegisteredRunners()).toBe(1);
+	});
+
+	it('should stop an disconnect the task runner', async () => {
+		// Arrange
+		await runnerProcess.start();
+
+		// Wait until the runner has connected
+		await retryUntil(() => expect(getNumConnectedRunners()).toBe(1));
+		expect(getNumRegisteredRunners()).toBe(1);
+
+		// Act
+		await runnerProcess.stop();
+
+		// Assert
+		// Wait until the runner has disconnected
+		await retryUntil(() => expect(getNumConnectedRunners()).toBe(0));
+
+		expect(runnerProcess.isRunning).toBeFalsy();
+		expect(getNumRegisteredRunners()).toBe(0);
+	});
+
+	it('should restart the task runner if it exits', async () => {
+		// Arrange
+		await runnerProcess.start();
+
+		// Wait until the runner has connected
+		await retryUntil(() => expect(getNumConnectedRunners()).toBe(1));
+		const processId = runnerProcess.pid;
+
+		// Act
+		// @ts-expect-error private property
+		runnerProcess.process?.kill('SIGKILL');
+
+		// Wait until the runner has exited
+		await runnerProcess.runPromise;
+
+		// Assert
+		// Wait until the runner has connected again
+		await retryUntil(() => expect(getNumConnectedRunners()).toBe(1));
+		expect(getNumConnectedRunners()).toBe(1);
+		expect(getNumRegisteredRunners()).toBe(1);
+		expect(runnerProcess.pid).not.toBe(processId);
+	});
+
+	it('should work together with restart loop detector', async () => {
+		// Arrange
+		const restartLoopDetector = new TaskRunnerProcessRestartLoopDetector(runnerProcess);
+		let restartLoopDetectedEventEmitted = false;
+		restartLoopDetector.once('restart-loop-detected', () => {
+			restartLoopDetectedEventEmitted = true;
+		});
+
+		// Act
+		await runnerProcess.start();
+
+		// Simulate a restart loop
+		for (let i = 0; i < 5; i++) {
+			await retryUntil(() => {
+				expect(runnerProcess.pid).toBeDefined();
+			});
+
+			// @ts-expect-error private property
+			runnerProcess.process?.kill();
+
+			await new Promise((resolve) => {
+				runnerProcess.once('exit', resolve);
+			});
+		}
+
+		// Assert
+		expect(restartLoopDetectedEventEmitted).toBe(true);
+	});
+});