Fix Tests (ubuntu-latest, 3.x, debugger): replace gulp-typescript with direct tsc in compileCore task by Copilot · Pull Request #25998 · microsoft/vscode-python

Copilot · 2026-06-08T19:53:24Z

Root Cause

The compileCore gulp task used gulp-typescript v5.0.1, which has a bug when compiling TypeScript with module: "NodeNext" — it emits raw ES import statements in the .js output instead of converting them to CJS require() calls.

In Node.js v22.12+, when a .js file contains ES module syntax but there is no "type": "module" in the nearest package.json, Node.js reparses the file as ESM. In ESM mode, relative imports require explicit .js file extensions — which the compiled output lacks — causing:

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '...out/client/common/platform/fs-paths'
    imported from ...out/test/testBootstrap.js

Fix

Replaced the compileCore gulp task in gulpfile.js to invoke tsc directly using the project-local TypeScript binary (node_modules/typescript/bin/tsc), identical to how the existing compileApi task already works. This produces correct CJS output with require() calls. The now-unused gulp-typescript and typescript imports were also removed.

Testing

✅ npx gulp prePublishNonBundle compiles successfully
✅ Compiled testBootstrap.js uses CJS require() — no ESM reparsing warning
✅ node ./out/test/testBootstrap.js starts without ERR_MODULE_NOT_FOUND
✅ Lint: 0 errors
✅ CodeQL: 0 alerts

Original prompt

Migrate to ESLint 10 with flat config, types/node 22, and TypeScript 5.9.x. Create a PR.

Created from VS Code.

- Bump eslint ^8.57.1 → ^10.0.0 - Add @eslint/js ^10.0.0 (now a required explicit dep for flat config) - Bump @typescript-eslint/{eslint-plugin,parser} ^6.21.0 → ^8.61.0 - Bump eslint-config-prettier ^8.3.0 → ^10.1.8 - Bump typescript ~5.2 → ~5.9 - Replace eslint-plugin-import ^2 (no ESLint 10 support) with eslint-plugin-import-x ^4.16.2 (drop-in fork with ESLint 10 support) eslint.config.mjs: - Update import to use eslint-plugin-import-x - Remove prettier from plugins (eslint-config-prettier is not a plugin) - Remove rules deleted in @typescript-eslint v8: ban-types, no-loss-of-precision, no-extra-parens, no-var-requires - Rename no-empty-interface → no-empty-object-type (v8 replacement) - Turn off new v8 recommended rules to avoid flagging pre-existing code: no-unsafe-function-type, no-wrapper-object-types, no-unused-expressions - Turn off new ESLint 10 recommended rules: no-unassigned-vars, no-useless-assignment, preserve-caught-error Source files: remove stale eslint-disable @typescript-eslint/ban-types comments (rule removed in v8) from 11 files across src/client and src/test tsconfig.json, tsconfig.extension.json, pythonExtensionApi/tsconfig.json: - Add skipLibCheck: true to resolve type conflict between @types/eslint-scope (webpack transitive dep) and ESLint 10 bundled types

rzhao271 · 2026-06-09T16:12:48Z

@copilot Do not use skiplibcheck. Instead bump webpack.

Webpack 5.107.0 dropped @types/eslint-scope as a dependency, which resolves the type conflict with ESLint 10's bundled TypeScript declarations. This avoids the need for skipLibCheck: true.

Copilot · 2026-06-09T16:17:15Z

@copilot Do not use skiplibcheck. Instead bump webpack.

Done. Bumped webpack ^5.105.0 → ^5.107.0 (commit $(git -C /home/runner/work/vscode-python/vscode-python/microsoft/vscode-python rev-parse --short HEAD)). Webpack 5.107.0 dropped @types/eslint-scope as a direct dependency, which eliminates the type conflict with ESLint 10's bundled declarations. skipLibCheck: true has been removed from all three tsconfig files.

@copilot Do not use skiplibcheck. Instead bump webpack.

Done in 456b4c6. Bumped webpack ^5.105.0 → ^5.107.0 — that version dropped @types/eslint-scope as a direct dependency, eliminating the type conflict with ESLint 10's bundled declarations. skipLibCheck: true has been removed from all three tsconfig files.

rzhao271 · 2026-06-09T16:28:34Z

@copilot Fix peer dependency issues by upgrading or deleting outdated eslint helper dependencies.

eslint-plugin-jsx-a11y, eslint-plugin-react, and eslint-plugin-react-hooks are not imported in eslint.config.mjs. eslint-plugin-jsx-a11y@6.x has no ESLint 10-compatible release, causing npm install to fail without --legacy-peer-deps. Removing all three resolves the conflict and allows clean installs.

Copilot · 2026-06-09T16:33:34Z

@copilot Fix peer dependency issues by upgrading or deleting outdated eslint helper dependencies.

Done in c975d3a. Removed eslint-plugin-jsx-a11y, eslint-plugin-react, and eslint-plugin-react-hooks from package.json — none of them are imported in eslint.config.mjs, and eslint-plugin-jsx-a11y@6.x has no ESLint 10-compatible release. npm install now completes cleanly without --legacy-peer-deps.

rzhao271 · 2026-06-09T16:39:33Z

@copilot Confirm where eslint-plugin-react was being used. Does the project contain React files?

Copilot · 2026-06-09T16:41:39Z

@copilot Confirm where eslint-plugin-react was being used. Does the project contain React files?

The project contains no React files — no .jsx, no .tsx, and no import from 'react' anywhere in src/. The only occurrences of the word "react" in source files are:

src/client/testing/common/debugLauncher.ts — a plain English comment: // Only react to OUR session terminating
src/test/unittests.ts — process.env.NODE_ENV = 'production'; // Make sure react is using production bits or we can run out of memory. (referring to VS Code's own React-based UI renderer, not any React code in this extension)

eslint-plugin-react, eslint-plugin-react-hooks, and eslint-plugin-jsx-a11y were listed as dev dependencies in package.json but were never imported or configured in eslint.config.mjs. They were dead dependencies — safe to remove.

rzhao271 · 2026-06-09T16:45:58Z

@copilot Upgrade vscode/test-electron package to ^3.0.0.

Copilot · 2026-06-09T16:49:29Z

@copilot Upgrade vscode/test-electron package to ^3.0.0.

Done. Upgraded @vscode/test-electron from ^2.3.8 → ^3.0.0. All APIs used in src/test/ (runTests, downloadAndUnzipVSCode, resolveCliPathFromVSCodeExecutablePath, TestOptions) are still present in v3, so no source changes were needed.

…t to fix NodeNext CJS output

Initial plan

5b3d1c6

Copilot AI assigned Copilot and rzhao271 Jun 8, 2026

Copilot started work on behalf of rzhao271 June 8, 2026 19:53 View session

Copilot AI changed the title ~~[WIP] Migrate to ESLint 10 with flat config~~ Migrate to ESLint 10 (flat config), @typescript-eslint v8, TypeScript 5.9, @types/node 22 Jun 8, 2026

Copilot finished work on behalf of rzhao271 June 8, 2026 20:10

Copilot AI requested a review from rzhao271 June 8, 2026 20:10

rzhao271 approved these changes Jun 9, 2026

View reviewed changes

Copilot started work on behalf of rzhao271 June 9, 2026 16:13 View session

Bump webpack to ^5.107.0, remove skipLibCheck from tsconfigs

456b4c6

Webpack 5.107.0 dropped @types/eslint-scope as a dependency, which resolves the type conflict with ESLint 10's bundled TypeScript declarations. This avoids the need for skipLibCheck: true.

Copilot AI requested a review from rzhao271 June 9, 2026 16:18

Copilot finished work on behalf of rzhao271 June 9, 2026 16:18

Copilot started work on behalf of rzhao271 June 9, 2026 16:28 View session

Copilot finished work on behalf of rzhao271 June 9, 2026 16:34

Copilot started work on behalf of rzhao271 June 9, 2026 16:39 View session

Copilot finished work on behalf of rzhao271 June 9, 2026 16:41

Copilot started work on behalf of rzhao271 June 9, 2026 16:46 View session

Upgrade @vscode/test-electron to ^3.0.0

f0b905d

Copilot finished work on behalf of rzhao271 June 9, 2026 16:50

rzhao271 added the no-changelog No news entry required label Jun 9, 2026

rzhao271 added the skip-issue-check label Jun 9, 2026

rzhao271 added this to the 1.125.0 milestone Jun 9, 2026

Copilot started work on behalf of rzhao271 June 9, 2026 17:02 View session

Copilot AI added 2 commits June 9, 2026 17:14

Initial plan: fix compileCore gulp task to use tsc directly

b7701cd

Fix compileCore gulp task: use tsc directly instead of gulp-typescrip…

e0caa42

…t to fix NodeNext CJS output

Copilot AI changed the title ~~Migrate to ESLint 10 (flat config), @typescript-eslint v8, TypeScript 5.9, @types/node 22~~ Fix Tests (ubuntu-latest, 3.x, debugger): replace gulp-typescript with direct tsc in compileCore task Jun 9, 2026

Copilot finished work on behalf of rzhao271 June 9, 2026 17:18

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Fix Tests (ubuntu-latest, 3.x, debugger): replace gulp-typescript with direct tsc in compileCore task#25998

Fix Tests (ubuntu-latest, 3.x, debugger): replace gulp-typescript with direct tsc in compileCore task#25998
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