[Ladislau Szomoru (lszomoru)]

extensions/copilot/chat-lib (the @vscode/chat-lib npm package, extracted from the Copilot extension's sources) was a separate pnpm install root, with its own pnpm-workspace.yaml and pnpm-lock.yaml. It becomes a member of the extensions/copilot workspace: one pnpm install in extensions/copilot installs both, and Copilot's pnpm-lock.yaml records them. That takes the repository from 8 pnpm install roots to 7 (after #345794, #345795, #345797 and #345827).

What changed

• Lockfile and versions:
  • The extraction (extract-chat-lib) already syncs chat-lib's dependencies to Copilot's versions in every pipeline. The committed chat-lib package.json now has those versions too: @anthropic-ai/sdk ^0.82.0, @types/node 24.x, typescript = Copilot's @typescript/typescript6 alias.
  • In Copilot's lockfile, chat-lib's project uses Copilot's entries for all 28 dependencies the two share. The lockfile only gains the project; no packages, no snapshots, and Copilot's own project is unchanged.
• chat-lib/script/postinstall.ts: every Copilot install now runs it, also before the extraction has created chat-lib's sources. It skipped nothing before and failed ("Could not find the source directory for tokenizer files"); now it skips with a message. In a package installed from npm (dist/ present) it copies the same files as before.
• chat-lib/package.json compile: tsc → tsc6, the binary of the typescript that chat-lib declares (TypeScript 6). In its own install root, tsc came from @typescript/old (the same TypeScript 6.0.3) only because pnpm hoisted it. In Copilot's workspace, tsc is Copilot's @typescript/native (TypeScript 7), whose declaration emit fails on chat-lib (TS5088/TS7056).
• extractChatLib.ts / chatLibLockfile.ts:
  • copyLockedDependencies (which copied entries into chat-lib's own lockfile) becomes lockChatLibDependencies. It locks each changed dependency to the version Copilot's project locks in the shared lockfile, drops the entries no project uses anymore, and still resolves nothing.
  • The extraction then runs pnpm install --frozen-lockfile --ignore-scripts. Otherwise its own TypeScript check would use chat-lib's previous versions, which pnpm nests in chat-lib/node_modules.
  • Tests rewritten for the shared lockfile.
• extensions/copilot/pnpm-workspace.yaml:
  • packages: [chat-lib];
  • hoistWorkspacePackages: false. Without it, pnpm links chat-lib into node_modules/@vscode/chat-lib, and vsce package (pnpm exec vsce package in the Copilot pipeline) fails: its npm list --production reports the link and chat-lib's nested packages as extraneous (ELSPROBLEMS).
• CI (.github/actions/test-chat-lib; extensions/copilot/build/steps/{build,test}-chat-lib.yml and npm-package-next.yml for the npm package pipelines):
  • the extraction no longer deletes Copilot's node_modules;
  • chat-lib's dependencies are installed in extensions/copilot after the extraction;
  • then pnpm --dir chat-lib run postinstall runs, because pnpm skips lifecycle scripts when the workspace is already up to date. It copies the wasm and tokenizer files next to the extracted sources.
• build/npm/dirs.ts: chat-lib is a member of extensions/copilot (separateRootMembers). hoistWorkspacePackages is added to the known settings (workspaceConfig.ts).

For reviewers

• chat-lib's isolation in CI changes. The test-chat-lib action used to delete every node_modules above chat-lib, so chat-lib built and tested against only its own dependencies. Now its dependencies are in Copilot's node_modules, so a chat-lib import of a package that only Copilot declares would no longer fail in CI. Today it doesn't happen: the packed package installs and loads in a clean project (below). A follow-up could add that consumer check to the test-chat-lib action.
• Copilot's global overrides (zod, string_decoder, yauzl) now also apply to chat-lib's tests. The packages that ship are unaffected: npm consumers resolve chat-lib's dependencies themselves.
• Every Copilot install (and the root postinstall) now also installs chat-lib. It costs nothing extra: chat-lib uses Copilot's packages.
• Pre-existing, unchanged: the published @vscode/chat-lib (e.g. 0.73.0) runs tsx script/postinstall.js as postinstall, but tsx is a dev dependency, so npm install @vscode/chat-lib fails unless tsx is available or scripts are ignored.

How to test (macOS arm64; compared with main at b48b93587a9, same steps on both)

• pnpm install --frozen-lockfile at the root: passes, and chat-lib's postinstall skips. cd extensions/copilot && pnpm install --lockfile-only leaves the lockfile unchanged.
• Copilot VSIX:
  • pnpm run build, then pnpm exec vsce package -o copilot-chat.vsix --allow-package-secrets sendgrid (as in product-copilot.yml): 82 files, byte-identical to main's VSIX (bundles included).
  • npm list --production (what vsce reads) gives the same 280 paths as on main. Without hoistWorkspacePackages: false, vsce package failed.
• Built-in Copilot and the product: getProductionDependencies for '', remote, remote/web, extensions and extensions/copilot (233 / 142 / 26 / 1 / 279): name, version and location identical to main.
• chat-lib npm package, the pipeline steps from a clean tree:
  • install Copilot, extract, install and postinstall, version sync, pnpm run build, pnpm test: 19/19 tests pass;
  • pnpm pack: the same 2143 files as main's package. All compiled .js/.d.ts files are byte-identical; only package.json (compile) and script/postinstall.ts differ.
• The GitHub test-chat-lib action steps: same result.
• Drift case, when Copilot bumps a dependency that chat-lib shares (simulated with chat-lib's @anthropic-ai/sdk back on ^0.91.1 in the lockfile): the extraction updates 1 dependency, relocks it to Copilot's version, removes the stale nested copy, and the build and the 19 tests pass.
• Consumer of the packed package: npm install --ignore-scripts <tgz> into a clean project, require('@vscode/chat-lib') (11 exports), and tsc on a consumer file: same results as main's package. The package's postinstall (run with tsx) copies the same 12 wasm and 2 tokenizer files.
• cd extensions/copilot && pnpm run typecheck: passes. pnpm exec vitest --run script/test/chatLibLockfile.spec.ts: 5 passed.
• cd build && pnpm run typecheck: passes. node --test lib/test/pnpmLock.test.ts lib/test/installWithoutSaving.test.ts lib/test/cloudSandbox.test.ts lib/test/dependencies.test.ts lib/test/listNodeModules.test.ts lib/test/detectChanges.test.ts lib/test/detectMissingCaches.test.ts npm/pnpm/test/workspaceConfig.test.ts: 76 passed.
• Not run: the chat-lib jobs on Linux and Windows (they run on this PR) and the Azure Pipelines npm package pipeline (npm-package.yml, publishing off by default).

[Copilot]

🟢 Approval recommended

No active review issues remain for the chat-lib workspace consolidation.

No open issues 🎉

1 file not reviewed

• extensions/copilot/pnpm-lock.yaml: Generated file

What changed in this PR

This PR moves @vscode/chat-lib into the Copilot pnpm workspace, continuing the install-root consolidation and reducing the repository from eight install roots to seven.

Changes:

• Consolidates chat-lib’s dependencies into Copilot’s lockfile and aligns its declared versions and compiler command.
• Updates extraction to synchronize the shared lockfile and installed dependencies, while allowing postinstall to skip before sources exist.
• Adjusts CI and build tooling for workspace installation and explicit post-extraction asset copying.

No actionable findings remain. Linux/Windows chat-lib jobs and the Azure npm package pipeline remain validation gaps noted in the PR description.

File	Description
extensions/​copilot/​script/​test/​chatLibLockfile.spec.ts	Rewrites dependency-locking tests for the shared workspace.
extensions/​copilot/​script/​build/​extractChatLib.ts	Updates the shared lockfile and refreshes installed dependencies.
extensions/​copilot/​script/​build/​chatLibLockfile.ts	Locks chat-lib dependencies to Copilot’s versions and prunes unused entries.
extensions/​copilot/​pnpm-workspace.yaml	Adds chat-lib and disables workspace-package hoisting for packaging compatibility.
extensions/​copilot/​pnpm-lock.yaml	Adds chat-lib’s project using existing package entries.
extensions/​copilot/​chat-lib/​script/​postinstall.ts	Skips asset copying when extracted sources are absent.
extensions/​copilot/​chat-lib/​pnpm-workspace.yaml	Removes the standalone workspace configuration.
extensions/​copilot/​chat-lib/​pnpm-lock.yaml	Removes the standalone lockfile.
extensions/​copilot/​chat-lib/​package.json	Aligns dependency versions and switches compilation to tsc6.
extensions/​copilot/​build/​steps/​test-chat-lib.yml	Uses workspace installation and explicitly runs chat-lib postinstall.
extensions/​copilot/​build/​steps/​build-chat-lib.yml	Adapts package builds to the shared installation.
extensions/​copilot/​build/​npm-package-next.yml	Adapts next-package publishing preparation to the shared installation.
build/​npm/​pnpm/​workspaceConfig.ts	Recognizes hoistWorkspacePackages as a supported setting.
build/​npm/​dirs.ts	Registers chat-lib as a Copilot workspace member.
build/​lib/​test/​pnpmLock.test.ts	Tests chat-lib’s shared lockfile location.
.github/​actions/​test-chat-lib/​action.yml	Preserves Copilot dependencies and copies assets after extraction.

_{Review effort: Balanced}