test_runner: add new test file scenario into test-runner-watch

Author: pmarchini

test/parallel/test-runner-run-watch.mjs

@@ -38,7 +38,7 @@ function refresh() {
 
 const runner = join(import.meta.dirname, '..', 'fixtures', 'test-runner-watch.mjs');
 
-async function testWatch({ fileToUpdate, file, action = 'update', cwd = tmpdir.path }) {
+async function testWatch({ fileToUpdate, file, action = 'update', cwd = tmpdir.path, fileToCreate }) {
   const ran1 = util.createDeferredPromise();
   const ran2 = util.createDeferredPromise();
   const args = [runner];
@@ -123,10 +123,35 @@ async function testWatch({ fileToUpdate, file, action = 'update', cwd = tmpdir.p
     }
   };
 
+  const testCreate = async () => {
+    await ran1.promise;
+    const newFilePath = tmpdir.resolve(fileToCreate);
+    const interval = setInterval(
+      () => writeFileSync(
+        newFilePath,
+        'module.exports = {};'
+      ),
+      common.platformTimeout(1000)
+    );
+    await ran2.promise;
+    runs.push(currentRun);
+    clearInterval(interval);
+    child.kill();
+    await once(child, 'exit');
+
+    for (const run of runs) {
+      assert.match(run, /# tests 1/);
+      assert.match(run, /# pass 1/);
+      assert.match(run, /# fail 0/);
+      assert.match(run, /# cancelled 0/);
+    }
+  };
+
   action === 'update' && await testUpdate();
   action === 'rename' && await testRename();
   action === 'rename2' && await testRename();
   action === 'delete' && await testDelete();
+  action === 'create' && await testCreate();
 }
 
 describe('test runner watch mode', () => {
@@ -172,4 +197,8 @@ describe('test runner watch mode', () => {
       action: 'rename2'
     });
   });
+
+  it('should run new tests when a new file is created in the watched directory', async () => {
+    await testWatch({ action: 'create', fileToCreate: 'new-test-file.test.js' });
+  });
 });