ISSUE-13112: Add onTestCaseStart hook

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

@@ -14,3 +14,25 @@ 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 results for skip tests 1`] = `
+"onTestCaseResult: sample, status: pending, numExpectations: 0
+onTestFileResult testCaseResult 0: sample, status: pending, numExpectations: 0"
+`;
+
+exports[`Custom Reporters Integration on jest-circus push test case start 1`] = `
+"onTestCaseStart: test 1, mode: undefined, ancestorTitles: Custom Reporters
+onTestCaseResult: test 1, status: passed
+onTestCaseStart: test 2, mode: undefined, ancestorTitles: Custom Reporters
+onTestCaseResult: test 2, status: passed"
+`;
+
+exports[`Custom Reporters Integration on jest-circus push test case start for todo tests 1`] = `
+"onTestCaseStart: sample, mode: todo, ancestorTitles: Custom Reporters
+onTestCaseResult: sample, status: todo"
+`;
+
+exports[`Custom Reporters Integration on jest-circus push test case start for skip tests 1`] = `
+"onTestCaseStart: sample, mode: skip, ancestorTitles: Custom Reporters
+onTestCaseResult: sample, status: pending"
+`;

e2e/__tests__/customReportersOnCircus.test.ts

@@ -54,4 +54,55 @@ describe('Custom Reporters Integration on jest-circus', () => {
 
     expect(stdout).toMatchSnapshot();
   });
+
+  test('push test case results for skip tests', () => {
+    const {stdout} = runJest('custom-reporters', [
+      '--config',
+      JSON.stringify({
+        reporters: [
+          'default',
+          '<rootDir>/reporters/AssertionCountsReporter.js',
+        ],
+      }),
+      'skip.test.js',
+    ]);
+
+    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('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('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/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 +1,32 @@
+/**
+ * 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('.')}`,
+    );
+  }
+  onTestCaseResult(test, testCaseResult) {
+    console.log(
+      `onTestCaseResult: ${testCaseResult.title}, ` +
+        `status: ${testCaseResult.status}`,
+    );
+  }
+}
+
+module.exports = TestCaseStartReporter;

packages/jest-circus/src/testCaseReportHandler.ts

@@ -7,12 +7,22 @@
 
 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_start': {
+        const testCaseStartInfo = createTestCaseStartInfo(event.test);
+        sendMessageToJest('test-case-start', [testPath, testCaseStartInfo]);
+        break;
+      }
+      case 'test_skip':
       case 'test_todo':
       case 'test_done': {
         const testResult = makeSingleTestResult(event.test);

packages/jest-circus/src/utils.ts

@@ -328,19 +328,25 @@ export const makeRunResult = (
   unhandledErrors: unhandledErrors.map(_getError).map(getErrorStack),
 });
 
+const getTestNamesPath = (test: Circus.TestEntry): Circus.TestNamesPath => {
+  const titles = [];
+  let parent: Circus.TestEntry | Circus.DescribeBlock | undefined = test;
+  do {
+    titles.unshift(parent.name);
+  } while ((parent = parent.parent));
+
+  return titles;
+};
+
 export const makeSingleTestResult = (
   test: Circus.TestEntry,
 ): Circus.TestResult => {
   const {includeTestLocationInResult} = getState();
-  const testPath = [];
-  let parent: Circus.TestEntry | Circus.DescribeBlock | undefined = test;
 
   const {status} = test;
   invariant(status, 'Status should be present after tests are run.');
 
-  do {
-    testPath.unshift(parent.name);
-  } while ((parent = parent.parent));
+  const testPath = getTestNamesPath(test);
 
   let location = null;
   if (includeTestLocationInResult) {
@@ -402,14 +408,9 @@ const makeTestResults = (
 // Return a string that identifies the test (concat of parent describe block
 // names + test title)
 export const getTestID = (test: Circus.TestEntry): string => {
-  const titles = [];
-  let parent: Circus.TestEntry | Circus.DescribeBlock | undefined = test;
-  do {
-    titles.unshift(parent.name);
-  } while ((parent = parent.parent));
-
-  titles.shift(); // remove TOP_DESCRIBE_BLOCK_NAME
-  return titles.join(' ');
+  const testNamesPath = getTestNamesPath(test);
+  testNamesPath.shift(); // remove TOP_DESCRIBE_BLOCK_NAME
+  return testNamesPath.join(' ');
 };
 
 const _getError = (
@@ -464,6 +465,29 @@ export function invariant(
   }
 }
 
+type TestDescription = {
+  ancestorTitles: Array<string>;
+  fullName: string;
+  title: string;
+};
+
+const resolveTestCaseStartInfo = (
+  testNamesPath: Circus.TestNamesPath,
+): TestDescription => {
+  const ancestorTitles = testNamesPath.filter(
+    name => name !== ROOT_DESCRIBE_BLOCK_NAME,
+  );
+  const fullName = ancestorTitles.join(' ');
+  const title = testNamesPath[testNamesPath.length - 1];
+  // remove title
+  ancestorTitles.pop();
+  return {
+    ancestorTitles,
+    fullName,
+    title,
+  };
+};
+
 export const parseSingleTestResult = (
   testResult: Circus.TestResult,
 ): AssertionResult => {
@@ -478,24 +502,36 @@ export const parseSingleTestResult = (
     status = 'passed';
   }
 
-  const ancestorTitles = testResult.testPath.filter(
-    name => name !== ROOT_DESCRIBE_BLOCK_NAME,
+  const {ancestorTitles, fullName, title} = resolveTestCaseStartInfo(
+    testResult.testPath,
   );
-  const title = ancestorTitles.pop();
 
   return {
     ancestorTitles,
     duration: testResult.duration,
     failureDetails: testResult.errorsDetailed,
     failureMessages: Array.from(testResult.errors),
-    fullName: title
-      ? ancestorTitles.concat(title).join(' ')
-      : ancestorTitles.join(' '),
+    fullName,
     invocations: testResult.invocations,
     location: testResult.location,
     numPassingAsserts: testResult.numPassingAsserts,
     retryReasons: Array.from(testResult.retryReasons),
     status,
-    title: testResult.testPath[testResult.testPath.length - 1],
+    title,
+  };
+};
+
+export const createTestCaseStartInfo = (
+  test: Circus.TestEntry,
+): Circus.TestCaseStartInfo => {
+  const testPath = getTestNamesPath(test);
+  const {ancestorTitles, fullName, title} = resolveTestCaseStartInfo(testPath);
+
+  return {
+    ancestorTitles,
+    fullName,
+    mode: test.mode,
+    startedAt: test.startedAt,
+    title,
   };
 };

packages/jest-core/src/ReporterDispatcher.ts

@@ -13,6 +13,7 @@ import type {
   TestContext,
   TestResult,
 } from '@jest/test-result';
+import type {Circus} from '@jest/types';
 import type {ReporterConstructor} from './TestScheduler';
 
 export default class ReporterDispatcher {
@@ -69,6 +70,17 @@ export default class ReporterDispatcher {
     }
   }
 
+  async onTestCaseStart(
+    test: Test,
+    testCaseStartInfo: Circus.TestCaseStartInfo,
+  ): Promise<void> {
+    for (const reporter of this._reporters) {
+      if (reporter.onTestCaseStart) {
+        await reporter.onTestCaseStart(test, testCaseStartInfo);
+      }
+    }
+  }
+
   async onTestCaseResult(
     test: Test,
     testCaseResult: TestCaseResult,

packages/jest-core/src/TestScheduler.ts

@@ -257,6 +257,13 @@ class TestScheduler {
                 testRunner.on('test-file-failure', ([test, error]) =>
                   onFailure(test, error),
                 ),
+                testRunner.on(
+                  'test-case-start',
+                  ([testPath, testCaseStartInfo]) => {
+                    const test: Test = {context, path: testPath};
+                    this._dispatcher.onTestCaseStart(test, testCaseStartInfo);
+                  },
+                ),
                 testRunner.on(
                   'test-case-result',
                   ([testPath, testCaseResult]) => {

packages/jest-reporters/src/types.ts

@@ -12,7 +12,7 @@ import type {
   TestContext,
   TestResult,
 } from '@jest/test-result';
-import type {Config} from '@jest/types';
+import type {Circus, Config} from '@jest/types';
 
 export type ReporterOnStartOptions = {
   estimatedTime: number;
@@ -30,6 +30,10 @@ export interface Reporter {
     testResult: TestResult,
     aggregatedResult: AggregatedResult,
   ) => Promise<void> | void;
+  readonly onTestCaseStart?: (
+    test: Test,
+    testCaseStartInfo: Circus.TestCaseStartInfo,
+  ) => Promise<void> | void;
   readonly onTestCaseResult?: (
     test: Test,
     testCaseResult: TestCaseResult,

packages/jest-test-result/src/types.ts

@@ -8,7 +8,7 @@
 import type {V8Coverage} from 'collect-v8-coverage';
 import type {CoverageMap, CoverageMapData} from 'istanbul-lib-coverage';
 import type {ConsoleBuffer} from '@jest/console';
-import type {Config, TestResult, TransformTypes} from '@jest/types';
+import type {Circus, Config, TestResult, TransformTypes} from '@jest/types';
 import type {IHasteFS, IModuleMap} from 'jest-haste-map';
 import type Resolver from 'jest-resolve';
 
@@ -197,6 +197,7 @@ export type TestEvents = {
   'test-file-start': [Test];
   'test-file-success': [Test, TestResult];
   'test-file-failure': [Test, SerializableError];
+  'test-case-start': [string, Circus.TestCaseStartInfo];
   'test-case-result': [string, AssertionResult];
 };
 

packages/jest-types/src/Circus.ts

@@ -178,6 +178,17 @@ export type MatcherResults = {
 };
 
 export type TestStatus = 'skip' | 'done' | 'todo';
+
+export type TestNamesPath = Array<TestName | BlockName>;
+
+export type TestCaseStartInfo = {
+  ancestorTitles: Array<string>;
+  fullName: string;
+  mode: TestMode;
+  title: string;
+  startedAt?: number | null;
+};
+
 export type TestResult = {
   duration?: number | null;
   errors: Array<FormattedError>;
@@ -187,7 +198,7 @@ export type TestResult = {
   location?: {column: number; line: number} | null;
   numPassingAsserts: number;
   retryReasons: Array<FormattedError>;
-  testPath: Array<TestName | BlockName>;
+  testPath: TestNamesPath;
 };
 
 export type RunResult = {