fix: fixed start test before task starting finishes

src/runner/browser-job.ts

@@ -20,8 +20,10 @@ interface BrowserJobResultInfo {
     data?: any; // eslint-disable-line @typescript-eslint/no-explicit-any
 }
 
+enum StartStatus { none, starting, started }
+
 export default class BrowserJob extends AsyncEventEmitter {
-    private _started: boolean;
+    private _startStatus: StartStatus;
     private _startTime: Date;
     private _total: number;
     private _passed: number;
@@ -53,7 +55,7 @@ export default class BrowserJob extends AsyncEventEmitter {
     }: BrowserJobInit) {
         super();
 
-        this._started   = false;
+        this._startStatus = StartStatus.none;
         this._startTime = new Date();
 
         this._total                = 0;
@@ -170,6 +172,11 @@ export default class BrowserJob extends AsyncEventEmitter {
     }
 
     private async _isNextTestRunAvailable (testRunController: TestRunController): Promise<boolean> {
+        // NOTE: event task start is currently executing,
+        // so test run is temporary blocked
+        if (this._startStatus === StartStatus.starting)
+            return false;
+
         // NOTE: before hook for test run fixture is currently
         // executing, so test run is temporary blocked
         const isBlocked                 = testRunController.blocked;
@@ -213,11 +220,13 @@ export default class BrowserJob extends AsyncEventEmitter {
             this._testRunControllerQueue.shift();
             this._addToCompletionQueue(testRunController);
 
-            if (!this._started) {
-                this._started   = true;
-                this._startTime = new Date();
+            if (this._startStatus === StartStatus.none) {
+                this._startStatus = StartStatus.starting;
+                this._startTime   = new Date();
 
                 await this.emit('start', this._startTime);
+
+                this._startStatus = StartStatus.started;
             }
 
             const testRunUrl = await testRunController.start(connection, this._startTime);

test/functional/fixtures/concurrency/test.js

@@ -77,6 +77,17 @@ if (config.useLocalBrowsers) {
             },
         });
 
+        const slowReporter = createReporter({
+            reportTaskStart: async function () {
+                await new Promise(resolve => setTimeout(() => resolve(), 100));
+                this.write('Task start').newline();
+            },
+
+            reportTestStart: async function () {
+                this.write('Test start').newline();
+            },
+        });
+
         beforeEach(function () {
             data = '';
         });
@@ -138,6 +149,19 @@ if (config.useLocalBrowsers) {
                 });
         });
 
+        it('Should not start any test before report task start finishes', function () {
+            return run('chrome:headless --no-sandbox', 2, './testcafe-fixtures/concurrent-test.js', slowReporter)
+                .then(failedCount => {
+                    expect(failedCount).eql(0);
+                    expect(data.split('\n')).eql([
+                        'Task start',
+                        'Test start',
+                        'Test start',
+                        '',
+                    ]);
+                });
+        });
+
         it('Should fail if number of remotes is not divisible by concurrency', function () {
             return createConnections(3)
                 .then(function (connections) {