Robo 9cd7264dd1 feat(copilot): opt-in HTTP cache for the Node fetch fetcher (#317721)
* feat(copilot): opt-in HTTP cache for the Node fetch fetcher

Adds an opportunistic cache support to the Copilot Node fetch path. The cache
is strictly opt-in per request and composes with the existing VSCode proxy
and CA-injection patch.

- `__vscodeCreateFetchPatch({ interceptors })` lets the extension host
  build a second proxy-aware `fetch` with extra undici interceptors. The
  default `__vscodePatchedFetch` is unchanged.
- `NodeFetchFetcher` builds an undici cache interceptor once at
  construction time and uses the factory to produce a `cachedFetch` that
  routes through both the proxy patch and the cache. Requests are tagged
  with an internal `__copilotCachePatch` marker (stripped before fetch);
  unmarked requests keep going through the regular patched fetch. When
  the host lacks the factory, caching is silently disabled so requests
  never bypass the proxy patch.
- `FetchOptions.cache?: boolean` — opportunistic hint. Fetchers without
  cache support ignore it; fallback to other fetchers is unaffected.
- `Response.cacheStatus` and `FetchTelemetryEvent.cacheStatus`:
  `'hit' | 'stale-hit' | 'revalidated' | 'miss' | 'bypass'`.
- New setting `github.copilot.advanced.debug.nodeFetchCache`:
  `'off' | 'memory' | 'persistent'` (default `'memory'`). `'persistent'`
  uses undici's SQLite store under the extension's global storage
  (`undici-cache.v1.sqlite`) when available, otherwise falls back to
  memory.
- New `taggedCacheInterceptor` wraps `undici.interceptors.cache` and
  stamps a private `VSCODE_CACHE_STATUS_HEADER` on the response so the
  base fetcher can read the outcome without parsing undici internals.
- `BaseFetchFetcher` exposes an overridable `_buildRequestInit` hook and
  reports `cacheStatus` on `Response` and `fetchTelemetry`.

Notes
- No behavior change for callers that don't set `cache: true`.
- The cache interceptor is constructed once per fetcher instance; the
  composed dispatcher chain is reused so connection pooling is preserved.
- Depends on https://github.com/microsoft/vscode-proxy-agent/pull/100

For https://github.com/microsoft/vscode/issues/308310

* fix: undici integration tests

- drop the `age` header gate from classify(): undici's cache interceptor
only adds if-modified-since / if-none-match when revalidating a stored
entry, so `state.conditional` alone is a sufficient signal. The age header
is not guaranteed on a revalidated 200, which caused 'revalidated' to be
misreported as 'miss'.

- the etag integration test used
`cache-control: max-age=0, must-revalidate`, which undici treats as
already-stale on arrival and refuses to store (cache-handler.js bails when
`now >= absoluteStaleAt`), so there was nothing to revalidate on the second
call. Switch the origin to `public, max-age=60` and pass
`cache-control: no-cache` on the second request to drive undici's
needsRevalidation() path, which dispatches with if-none-match and serves
the cached body on 304.

* chore: fix lint

* chore: cleanup cache marker in favor of function arg
2026-05-21 18:07:34 +00:00
2026-05-19 23:06:02 -07:00
2026-05-19 23:06:02 -07:00
2026-05-19 23:06:02 -07:00
2026-03-16 14:51:48 +00:00
2026-05-15 12:43:43 -04:00

Visual Studio Code - Open Source ("Code - OSS")

Feature Requests Bugs Gitter

The Repository

This repository ("Code - OSS") is where we (Microsoft) develop the Visual Studio Code product together with the community. Not only do we work on code and issues here, but we also publish our roadmap, monthly iteration plans, and our endgame plans. This source code is available to everyone under the standard MIT license.

Visual Studio Code

VS Code in action

Visual Studio Code is a distribution of the Code - OSS repository with Microsoft-specific customizations released under a traditional Microsoft product license.

Visual Studio Code combines the simplicity of a code editor with what developers need for their core edit-build-debug cycle. It provides comprehensive code editing, navigation, and understanding support along with lightweight debugging, a rich extensibility model, and lightweight integration with existing tools.

Visual Studio Code is updated monthly with new features and bug fixes. You can download it for Windows, macOS, and Linux on Visual Studio Code's website. To get the latest releases every day, install the Insiders build.

Contributing

There are many ways in which you can participate in this project, for example:

If you are interested in fixing issues and contributing directly to the code base, please see the document How to Contribute, which covers the following:

Feedback

See our wiki for a description of each of these channels and information on some other available community-driven channels.

Many of the core components and extensions to VS Code live in their own repositories on GitHub. For example, the node debug adapter and the mono debug adapter repositories are separate from each other. For a complete list, please visit the Related Projects page on our wiki.

Bundled Extensions

VS Code includes a set of built-in extensions located in the extensions folder, including grammars and snippets for many languages. Extensions that provide rich language support (inline suggestions, Go to Definition) for a language have the suffix language-features. For example, the json extension provides coloring for JSON and the json-language-features extension provides rich language support for JSON.

Development Container

This repository includes a Visual Studio Code Dev Containers / GitHub Codespaces development container.

  • For Dev Containers, use the Dev Containers: Clone Repository in Container Volume... command which creates a Docker volume for better disk I/O on macOS and Windows.

    • If you already have VS Code and Docker installed, you can also click here to get started. This will cause VS Code to automatically install the Dev Containers extension if needed, clone the source code into a container volume, and spin up a dev container for use.
  • For Codespaces, install the GitHub Codespaces extension in VS Code, and use the Codespaces: Create New Codespace command.

Docker / the Codespace should have at least 4 cores and 6 GB of RAM (8 GB recommended) to run a full build. See the development container README for more information.

Code of Conduct

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

License

Copyright (c) Microsoft Corporation. All rights reserved.

Licensed under the MIT license.

S
Description
Languages
TypeScript 77.6%
jsonc 18.1%
CSS 1.4%
JavaScript 0.7%
C 0.7%
Other 1.2%