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-module.external.test.ts

@@ -0,0 +1,54 @@
+import { TaskRunnersConfig } from '@n8n/config';
+import { Container } from '@n8n/di';
+import { mock } from 'jest-mock-extended';
+
+import { MissingAuthTokenError } from '@/task-runners/errors/missing-auth-token.error';
+import { TaskRunnerModule } from '@/task-runners/task-runner-module';
+
+import { DefaultTaskRunnerDisconnectAnalyzer } from '../../../src/task-runners/default-task-runner-disconnect-analyzer';
+import { TaskRunnerWsServer } from '../../../src/task-runners/task-runner-ws-server';
+
+describe('TaskRunnerModule in external mode', () => {
+	const runnerConfig = Container.get(TaskRunnersConfig);
+	runnerConfig.mode = 'external';
+	runnerConfig.port = 0;
+	runnerConfig.authToken = 'test';
+	const module = Container.get(TaskRunnerModule);
+
+	afterEach(async () => {
+		await module.stop();
+	});
+
+	describe('start', () => {
+		it('should throw if the task runner is disabled', async () => {
+			runnerConfig.enabled = false;
+
+			// Act
+			await expect(module.start()).rejects.toThrow('Task runner is disabled');
+		});
+
+		it('should throw if auth token is missing', async () => {
+			const runnerConfig = new TaskRunnersConfig();
+			runnerConfig.mode = 'external';
+			runnerConfig.enabled = true;
+			runnerConfig.authToken = '';
+
+			const module = new TaskRunnerModule(mock(), mock(), runnerConfig);
+
+			await expect(module.start()).rejects.toThrowError(MissingAuthTokenError);
+		});
+
+		it('should start the task runner', async () => {
+			runnerConfig.enabled = true;
+
+			// Act
+			await module.start();
+		});
+
+		it('should use DefaultTaskRunnerDisconnectAnalyzer', () => {
+			const wsServer = Container.get(TaskRunnerWsServer);
+
+			expect(wsServer.getDisconnectAnalyzer()).toBeInstanceOf(DefaultTaskRunnerDisconnectAnalyzer);
+		});
+	});
+});