feat(jest-circus): add onTestCaseStart hook Reporter

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - `[jest-cli]` Include type definitions to generated config files ([#14078](https://github.com/facebook/jest/pull/14078))
 - `[jest-snapshot]` Support arrays as property matchers ([#14025](https://github.com/facebook/jest/pull/14025))
+- `[jest-core, jest-circus, jest-reporter, jest-runner]` Added support for reporting about start individual test cases using jest-circus ([#14174](https://github.com/jestjs/jest/pull/14174))
 
 ### Fixes
 

e2e/__tests__/__snapshots__/customReportersOnCircus.test.ts.snap

@@ -14,3 +14,12 @@ exports[`Custom Reporters Integration on jest-circus push test case results for
 "onTestCaseResult: sample, status: todo, numExpectations: 0
 onTestFileResult testCaseResult 0: sample, status: todo, numExpectations: 0"
 `;
+
+exports[`Custom Reporters Integration on jest-circus push test case start 1`] = `
+"onTestCaseStart: test 1, mode: undefined, ancestorTitles: Custom Reporters
+onTestCaseStart: test 2, mode: undefined, ancestorTitles: Custom Reporters"
+`;
+
+exports[`Custom Reporters Integration on jest-circus doesn't push test case start for skip tests 1`] = `""`;
+
+exports[`Custom Reporters Integration on jest-circus doesn't push test case start for todo tests 1`] = `""`;

e2e/__tests__/customReportersOnCircus.test.ts

@@ -54,4 +54,40 @@ describe('Custom Reporters Integration on jest-circus', () => {
 
     expect(stdout).toMatchSnapshot();
   });
+
+  test('push test case start', () => {
+    const {stdout} = runJest('custom-reporters', [
+      '--config',
+      JSON.stringify({
+        reporters: ['default', '<rootDir>/reporters/TestCaseStartReporter.js'],
+      }),
+      'just2Tests.test.js',
+    ]);
+
+    expect(stdout).toMatchSnapshot();
+  });
+
+  test("doesn't push test case start for todo tests", () => {
+    const {stdout} = runJest('custom-reporters', [
+      '--config',
+      JSON.stringify({
+        reporters: ['default', '<rootDir>/reporters/TestCaseStartReporter.js'],
+      }),
+      'todo.test.js',
+    ]);
+
+    expect(stdout).toMatchSnapshot();
+  });
+
+  test("doesn't push test case start for skip tests", () => {
+    const {stdout} = runJest('custom-reporters', [
+      '--config',
+      JSON.stringify({
+        reporters: ['default', '<rootDir>/reporters/TestCaseStartReporter.js'],
+      }),
+      'skip.test.js',
+    ]);
+
+    expect(stdout).toMatchSnapshot();
+  });
 });

e2e/__tests__/testEnvironmentCircus.test.ts

@@ -23,6 +23,7 @@ it('calls testEnvironment handleTestEvent', () => {
       "run_start",
       "run_describe_start",
       "test_start: test name here",
+      "test_started: test name here",
       "hook_start",
       "hook_success: test name here",
       "hook_start",
@@ -31,6 +32,7 @@ it('calls testEnvironment handleTestEvent', () => {
       "test_fn_success: test name here",
       "test_done: test name here",
       "test_start: second test name here",
+      "test_started: second test name here",
       "hook_start",
       "hook_success: second test name here",
       "hook_start",

e2e/__tests__/testEnvironmentCircusAsync.test.ts

@@ -36,6 +36,7 @@ it('calls asynchronous handleTestEvent in testEnvironment', () => {
       "run_describe_start",
       "run_describe_start",
       "test_start: passing test",
+      "test_started: passing test",
       "hook_start: beforeEach",
       "hook_success: beforeEach",
       "hook_start: beforeEach",
@@ -46,6 +47,7 @@ it('calls asynchronous handleTestEvent in testEnvironment', () => {
       "hook_failure: afterEach",
       "test_done: passing test",
       "test_start: failing test",
+      "test_started: failing test",
       "hook_start: beforeEach",
       "hook_success: beforeEach",
       "hook_start: beforeEach",

e2e/custom-reporters/__tests__/just2Tests.test.js

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
+'use strict';
+
+describe('Custom Reporters', () => {
+  it('test 1', () => {
+    expect(true).toBeTruthy();
+  });
+
+  it('test 2', () => {
+    expect(true).toBeTruthy();
+  });
+});

e2e/custom-reporters/__tests__/skip.test.js

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
+'use strict';
+
+describe('Custom Reporters', () => {
+  it.skip('sample', () => {});
+});

e2e/custom-reporters/reporters/TestCaseStartReporter.js

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+/**
+ * @class
+ * @implements {import('@jest/reporters').Reporter}
+ */
+class TestCaseStartReporter {
+  onTestCaseStart(test, testCaseStartInfo) {
+    const mode =
+      testCaseStartInfo.mode != null ? testCaseStartInfo.mode : 'undefined';
+    console.log(
+      `onTestCaseStart: ${testCaseStartInfo.title}, ` +
+        `mode: ${mode}, ` +
+        `ancestorTitles: ${testCaseStartInfo.ancestorTitles.join('.')}`,
+    );
+  }
+}
+
+module.exports = TestCaseStartReporter;

packages/jest-circus/src/__mocks__/testEventHandler.ts

@@ -20,6 +20,7 @@ const testEventHandler: Circus.EventHandler = (event, state) => {
       break;
     }
     case 'test_start':
+    case 'test_started':
     case 'test_retry':
     case 'test_done': {
       console.log(`${event.name}:`, event.test.name);

packages/jest-circus/src/__tests__/__snapshots__/afterAll.test.ts.snap

@@ -54,6 +54,7 @@ hook_start: beforeAll
 hook_success: beforeAll
 run_describe_start: child describe
 test_start: my test
+test_started: my test
 hook_start: beforeEach
 > beforeEach
 hook_success: beforeEach
@@ -132,24 +133,29 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
+test_started: one
 test_fn_start: one
 test_fn_success: one
 test_done: one
 test_start: two
+test_started: two
 test_fn_start: two
 test_fn_success: two
 test_done: two
 run_describe_start: 2nd level describe
 test_start: 2nd level test
+test_started: 2nd level test
 test_fn_start: 2nd level test
 test_fn_success: 2nd level test
 test_done: 2nd level test
 run_describe_start: 3rd level describe
 test_start: 3rd level test
+test_started: 3rd level test
 test_fn_start: 3rd level test
 test_fn_success: 3rd level test
 test_done: 3rd level test
 test_start: 3rd level test#2
+test_started: 3rd level test#2
 test_fn_start: 3rd level test#2
 test_fn_success: 3rd level test#2
 test_done: 3rd level test#2
@@ -162,6 +168,7 @@ hook_success: afterAll
 run_describe_finish: describe
 run_describe_start: 2nd describe
 test_start: 2nd describe test
+test_started: 2nd describe test
 test_fn_start: 2nd describe test
 test_fn_success: 2nd describe test
 test_done: 2nd describe test

packages/jest-circus/src/__tests__/__snapshots__/baseTest.test.ts.snap

@@ -11,6 +11,7 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
+test_started: one
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: one
@@ -19,6 +20,7 @@ hook_start: afterEach
 hook_failure: afterEach
 test_done: one
 test_start: two
+test_started: two
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: two
@@ -41,6 +43,7 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describer
 test_start: One
+test_started: One
 test_fn_start: One
 test_fn_success: One
 test_done: One
@@ -62,6 +65,7 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
+test_started: one
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: one
@@ -70,6 +74,7 @@ hook_start: afterEach
 hook_success: afterEach
 test_done: one
 test_start: two
+test_started: two
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: two

packages/jest-circus/src/__tests__/__snapshots__/hooks.test.ts.snap

@@ -17,6 +17,7 @@ hook_start: beforeAll
 > beforeAll 1
 hook_success: beforeAll
 test_start: test 1
+test_started: test 1
 test_fn_start: test 1
 > test 1
 test_fn_success: test 1
@@ -26,11 +27,13 @@ hook_start: beforeAll
 > beforeAll 2
 hook_success: beforeAll
 test_start: test 2
+test_started: test 2
 test_fn_start: test 2
 > test 2
 test_fn_success: test 2
 test_done: test 2
 test_start: test 3
+test_started: test 3
 test_fn_start: test 3
 > test 3
 test_fn_success: test 3
@@ -65,13 +68,15 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
+test_started: one
 hook_start: beforeEach
 > describe beforeEach
 hook_success: beforeEach
 test_fn_start: one
 test_fn_success: one
 test_done: one
 test_start: two
+test_started: two
 hook_start: beforeEach
 > describe beforeEach
 hook_success: beforeEach
@@ -80,6 +85,7 @@ test_fn_success: two
 test_done: two
 run_describe_start: 2nd level describe
 test_start: 2nd level test
+test_started: 2nd level test
 hook_start: beforeEach
 > describe beforeEach
 hook_success: beforeEach
@@ -91,6 +97,7 @@ test_fn_success: 2nd level test
 test_done: 2nd level test
 run_describe_start: 3rd level describe
 test_start: 3rd level test
+test_started: 3rd level test
 hook_start: beforeEach
 > describe beforeEach
 hook_success: beforeEach
@@ -101,6 +108,7 @@ test_fn_start: 3rd level test
 test_fn_success: 3rd level test
 test_done: 3rd level test
 test_start: 3rd level test#2
+test_started: 3rd level test#2
 hook_start: beforeEach
 > describe beforeEach
 hook_success: beforeEach
@@ -115,6 +123,7 @@ run_describe_finish: 2nd level describe
 run_describe_finish: describe
 run_describe_start: 2nd describe
 test_start: 2nd describe test
+test_started: 2nd describe test
 hook_start: beforeEach
 > 2nd describe beforeEach that throws
 hook_failure: beforeEach
@@ -140,6 +149,7 @@ run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe 1
 run_describe_start: 2nd level describe
 test_start: test
+test_started: test
 hook_start: beforeEach
 before each 1
 hook_success: beforeEach

packages/jest-circus/src/__tests__/__snapshots__/randomizeTest.test.ts.snap

@@ -11,6 +11,7 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
+test_started: one
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: one
@@ -19,6 +20,7 @@ hook_start: afterEach
 hook_failure: afterEach
 test_done: one
 test_start: two
+test_started: two
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: two
@@ -41,6 +43,7 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describer
 test_start: One
+test_started: One
 test_fn_start: One
 test_fn_success: One
 test_done: One
@@ -62,6 +65,7 @@ run_start
 run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
+test_started: one
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: one
@@ -70,6 +74,7 @@ hook_start: afterEach
 hook_success: afterEach
 test_done: one
 test_start: two
+test_started: two
 hook_start: beforeEach
 hook_success: beforeEach
 test_fn_start: two

packages/jest-circus/src/run.ts

@@ -166,6 +166,8 @@ const _runTest = async (
     return;
   }
 
+  await dispatch({name: 'test_started', test});
+
   const {afterEach, beforeEach} = getEachHooksForTest(test);
 
   for (const hook of beforeEach) {

packages/jest-circus/src/testCaseReportHandler.ts

@@ -7,12 +7,21 @@
 
 import type {TestFileEvent} from '@jest/test-result';
 import type {Circus} from '@jest/types';
-import {makeSingleTestResult, parseSingleTestResult} from './utils';
+import {
+  createTestCaseStartInfo,
+  makeSingleTestResult,
+  parseSingleTestResult,
+} from './utils';
 
 const testCaseReportHandler =
   (testPath: string, sendMessageToJest: TestFileEvent) =>
   (event: Circus.Event): void => {
     switch (event.name) {
+      case 'test_started': {
+        const testCaseStartInfo = createTestCaseStartInfo(event.test);
+        sendMessageToJest('test-case-start', [testPath, testCaseStartInfo]);
+        break;
+      }
       case 'test_todo':
       case 'test_done': {
         const testResult = makeSingleTestResult(event.test);