From cfc5f072752591ef3efdbf7f0e3fb536d905b08f Mon Sep 17 00:00:00 2001
From: Eric tyrrell <eric.tyrrell18+github@gmail.com>
Date: Sat, 16 Sep 2023 13:50:00 -0400
Subject: [PATCH] feat(test-sequencer): Exposes globalConfig

---
 e2e/__tests__/customTestSequencers.test.ts    | 53 +++++++++++++++++++
 .../testSequencerWithSeed.js                  | 19 +++++++
 packages/jest-core/src/runJest.ts             |  2 +-
 packages/jest-test-sequencer/src/index.ts     |  3 ++
 4 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 e2e/custom-test-sequencer/testSequencerWithSeed.js

diff --git a/e2e/__tests__/customTestSequencers.test.ts b/e2e/__tests__/customTestSequencers.test.ts
index 40f0c43fc3cf..7feb8d1e6c13 100644
--- a/e2e/__tests__/customTestSequencers.test.ts
+++ b/e2e/__tests__/customTestSequencers.test.ts
@@ -79,3 +79,56 @@ test('run failed tests async', () => {
     .split('\n');
   expect(sequence).toEqual(['./c.test.js', './d.test.js']);
 });
+
+test('run tests based on even seed', () => {
+  const result = runJest(
+    dir,
+    [
+      '-i',
+      '--config',
+      JSON.stringify({
+        testSequencer: '<rootDir>/testSequencerWithSeed.js',
+      }),
+      '--seed=2',
+    ],
+    {},
+  );
+  console.log({result});
+  expect(result.exitCode).toBe(0);
+  const sequence = extractSummary(result.stderr)
+    .rest.replace(/PASS /g, '')
+    .split('\n');
+  expect(sequence).toEqual([
+    './a.test.js',
+    './b.test.js',
+    './c.test.js',
+    './d.test.js',
+    './e.test.js',
+  ]);
+});
+
+test('run tests based on odd seed', () => {
+  const result = runJest(
+    dir,
+    [
+      '-i',
+      '--config',
+      JSON.stringify({
+        testSequencer: '<rootDir>/testSequencerWithSeed.js',
+      }),
+      '--seed=1',
+    ],
+    {},
+  );
+  expect(result.exitCode).toBe(0);
+  const sequence = extractSummary(result.stderr)
+    .rest.replace(/PASS /g, '')
+    .split('\n');
+  expect(sequence).toEqual([
+    './e.test.js',
+    './d.test.js',
+    './c.test.js',
+    './b.test.js',
+    './a.test.js',
+  ]);
+});
diff --git a/e2e/custom-test-sequencer/testSequencerWithSeed.js b/e2e/custom-test-sequencer/testSequencerWithSeed.js
new file mode 100644
index 000000000000..43f8b86a39a3
--- /dev/null
+++ b/e2e/custom-test-sequencer/testSequencerWithSeed.js
@@ -0,0 +1,19 @@
+const Sequencer = require('@jest/test-sequencer').default;
+
+class CustomSequencer extends Sequencer {
+  sort(tests) {
+    const copyTests = Array.from(tests);
+    const seed = this.globalConfig.seed;
+    const sortedTests = copyTests.sort((testA, testB) =>
+      testA.path > testB.path ? 1 : -1,
+    );
+
+    if (seed % 2 === 0) {
+      return sortedTests;
+    } else {
+      return sortedTests.reverse();
+    }
+  }
+}
+
+module.exports = CustomSequencer;
diff --git a/packages/jest-core/src/runJest.ts b/packages/jest-core/src/runJest.ts
index 45b31137d292..5b097ecd4d4d 100644
--- a/packages/jest-core/src/runJest.ts
+++ b/packages/jest-core/src/runJest.ts
@@ -159,7 +159,7 @@ export default async function runJest({
   const Sequencer: typeof TestSequencer = await requireOrImportModule(
     globalConfig.testSequencer,
   );
-  const sequencer = new Sequencer();
+  const sequencer = new Sequencer(globalConfig);
   let allTests: Array<Test> = [];
 
   if (changedFilesPromise && globalConfig.watch) {
diff --git a/packages/jest-test-sequencer/src/index.ts b/packages/jest-test-sequencer/src/index.ts
index 0a8239e8ce63..2946df37fe7c 100644
--- a/packages/jest-test-sequencer/src/index.ts
+++ b/packages/jest-test-sequencer/src/index.ts
@@ -10,6 +10,7 @@ import * as path from 'path';
 import * as fs from 'graceful-fs';
 import slash = require('slash');
 import type {AggregatedResult, Test, TestContext} from '@jest/test-result';
+import type {Config} from '@jest/types';
 import HasteMap from 'jest-haste-map';
 
 const FAIL = 0;
@@ -46,6 +47,8 @@ type ShardPositionOptions = ShardOptions & {
 export default class TestSequencer {
   private readonly _cache = new Map<TestContext, Cache>();
 
+  constructor(protected readonly globalConfig: Config.GlobalConfig) {}
+
   _getCachePath(testContext: TestContext): string {
     const {config} = testContext;
     const HasteMapClass = HasteMap.getStatic(config);