From 0eab3273e704e6bf34dbd355d87faf40dc0fdb27 Mon Sep 17 00:00:00 2001
From: Gamote <38785171+Gamote@users.noreply.github.com>
Date: Thu, 22 Oct 2020 11:32:22 +0200
Subject: [PATCH] Fix for the `jest.config.ts` compiler to not interfere with
 `tsconfig.json` files (#10675)

---
 CHANGELOG.md                                    |  1 +
 .../__snapshots__/jest.config.js.test.ts.snap   |  2 +-
 .../__snapshots__/jest.config.ts.test.ts.snap   | 15 ++++++++++++++-
 e2e/__tests__/jest.config.js.test.ts            |  2 +-
 e2e/__tests__/jest.config.ts.test.ts            | 17 ++++++++++++++++-
 .../src/readConfigFileAndSetRootDir.ts          |  6 +++++-
 6 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eaee24dc0baa..41669d689333 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 ### Fixes
 
 - `[expect]` Fix `objectContaining` to work recursively into sub-objects ([#10508](https://github.com/facebook/jest/pull/10508))
+- `[jest-config]` Fix for the `jest.config.ts` compiler to not interfere with `tsconfig.json` files ([#10675](https://github.com/facebook/jest/pull/10675))
 - `[jest-message-util]` Update to work properly with Node 15 ([#10660](https://github.com/facebook/jest/pull/10660))
 - `[jest-mock]` Allow to mock methods in getters (TypeScript 3.9 export) ([#10156](https://github.com/facebook/jest/pull/10156))
 
diff --git a/e2e/__tests__/__snapshots__/jest.config.js.test.ts.snap b/e2e/__tests__/__snapshots__/jest.config.js.test.ts.snap
index db94a91b08e4..9bf15c021352 100644
--- a/e2e/__tests__/__snapshots__/jest.config.js.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/jest.config.js.test.ts.snap
@@ -2,7 +2,7 @@
 
 exports[`traverses directory tree up until it finds jest.config 1`] = `
   console.log
-<<REPLACED>>/jest.config.js/some/nested/directory
+<<REPLACED>>/jest-config-js/some/nested/directory
 
       at Object.log (__tests__/a-banana.js:3:27)
 
diff --git a/e2e/__tests__/__snapshots__/jest.config.ts.test.ts.snap b/e2e/__tests__/__snapshots__/jest.config.ts.test.ts.snap
index 231d926a36de..5930200701cb 100644
--- a/e2e/__tests__/__snapshots__/jest.config.ts.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/jest.config.ts.test.ts.snap
@@ -2,7 +2,7 @@
 
 exports[`traverses directory tree up until it finds jest.config 1`] = `
   console.log
-<<REPLACED>>/jest.config.ts/some/nested/directory
+<<REPLACED>>/jest-config-ts/some/nested/directory
 
       at Object.log (__tests__/a-giraffe.js:3:27)
 
@@ -34,3 +34,16 @@ Snapshots:   0 total
 Time:        <<REPLACED>>
 Ran all test suites.
 `;
+
+exports[`works with tsconfig.json 1`] = `
+PASS __tests__/a-giraffe.js
+  ✓ giraffe
+`;
+
+exports[`works with tsconfig.json 2`] = `
+Test Suites: 1 passed, 1 total
+Tests:       1 passed, 1 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites.
+`;
diff --git a/e2e/__tests__/jest.config.js.test.ts b/e2e/__tests__/jest.config.js.test.ts
index 5fd47a0ba1c9..a81611071cd7 100644
--- a/e2e/__tests__/jest.config.js.test.ts
+++ b/e2e/__tests__/jest.config.js.test.ts
@@ -10,7 +10,7 @@ import {wrap} from 'jest-snapshot-serializer-raw';
 import runJest from '../runJest';
 import {cleanup, extractSummary, writeFiles} from '../Utils';
 
-const DIR = path.resolve(__dirname, '../jest.config.js');
+const DIR = path.resolve(__dirname, '../jest-config-js');
 
 beforeEach(() => cleanup(DIR));
 afterAll(() => cleanup(DIR));
diff --git a/e2e/__tests__/jest.config.ts.test.ts b/e2e/__tests__/jest.config.ts.test.ts
index 9b3edcef87ff..d93dc33bfd84 100644
--- a/e2e/__tests__/jest.config.ts.test.ts
+++ b/e2e/__tests__/jest.config.ts.test.ts
@@ -10,7 +10,7 @@ import {wrap} from 'jest-snapshot-serializer-raw';
 import runJest from '../runJest';
 import {cleanup, extractSummary, writeFiles} from '../Utils';
 
-const DIR = path.resolve(__dirname, '../jest.config.ts');
+const DIR = path.resolve(__dirname, '../jest-config-ts');
 
 beforeEach(() => cleanup(DIR));
 afterAll(() => cleanup(DIR));
@@ -29,6 +29,21 @@ test('works with jest.config.ts', () => {
   expect(wrap(summary)).toMatchSnapshot();
 });
 
+test('works with tsconfig.json', () => {
+  writeFiles(DIR, {
+    '__tests__/a-giraffe.js': `test('giraffe', () => expect(1).toBe(1));`,
+    'jest.config.ts': `export default {testEnvironment: 'jest-environment-node', testRegex: '.*-giraffe.js'};`,
+    'package.json': '{}',
+    'tsconfig.json': '{ "compilerOptions": { "module": "esnext" } }',
+  });
+
+  const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false']);
+  const {rest, summary} = extractSummary(stderr);
+  expect(exitCode).toBe(0);
+  expect(wrap(rest)).toMatchSnapshot();
+  expect(wrap(summary)).toMatchSnapshot();
+});
+
 test('traverses directory tree up until it finds jest.config', () => {
   writeFiles(DIR, {
     '__tests__/a-giraffe.js': `
diff --git a/packages/jest-config/src/readConfigFileAndSetRootDir.ts b/packages/jest-config/src/readConfigFileAndSetRootDir.ts
index 47f1d6823efc..68cee0e87a6b 100644
--- a/packages/jest-config/src/readConfigFileAndSetRootDir.ts
+++ b/packages/jest-config/src/readConfigFileAndSetRootDir.ts
@@ -107,7 +107,11 @@ const loadTSConfigFile = async (
 
   // Register TypeScript compiler instance
   try {
-    registerer = require('ts-node').register();
+    registerer = require('ts-node').register({
+      compilerOptions: {
+        module: 'CommonJS',
+      },
+    });
   } catch (e) {
     if (e.code === 'MODULE_NOT_FOUND') {
       throw new Error(