[asukaminato0721]

Summary

Fixes part of #2207

ref microsoft/pylance-release#4972 (comment)

Added a client-side Python CodeLens provider that shows:
- $(arrow-up) Overrides ... on overriding methods
- $(arrow-down) Implemented by ... / implementation counts on parent methods
Registered the provider plus navigation/quick-pick commands

Implemented the provider

Test Plan

Added backend regression coverage for that parent-resolution path

[Copilot]

Pull request overview

This PR adds an overrides/implementations CodeLens experience for Python in the VS Code extension and extends the backend go-to-declaration behavior so overriding members can navigate to the overridden parent declaration (supporting class hierarchy/navigation work tracked in #2207).

Changes:

• Added a new VS Code OverrideCodeLensProvider that shows “Overrides …” and “Implemented by …” lenses based on declaration/implementation providers.
• Registered the provider and navigation/quick-pick commands in the extension activation flow.
• Updated backend goto_declaration to redirect overriding members to parent declarations, and added regression tests for method + class attribute overrides.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 6 comments.

File	Description
pyrefly/lib/test/lsp/definition.rs	Adds tests validating go-to-declaration jumps from overrides to parent declarations.
pyrefly/lib/state/lsp.rs	Adds override-parent lookup logic to goto_declaration plus a helper for resolving module info from a ModulePath.
lsp/src/overrideCodeLens.ts	Implements the CodeLens provider and navigation commands for override/implementation targets.
lsp/src/extension.ts	Registers the CodeLens provider, hooks refreshes, and registers navigation commands.

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[Copilot]

Refreshing CodeLenses on every onDidChangeTextDocument for Python means this provider will re-run (and potentially issue many LSP requests) on every keystroke. Consider debouncing this refresh (timer-based) and/or refreshing only on saves / when the edited document is the active editor to reduce churn.

[Copilot]

parent_declarations_for_definition always reads the solutions index for the current handle, but it looks up overrides by definition.range (a TextRange without module identity). If find_definition returns a definition in another module (e.g. imports/stubs), this can either miss the override info or accidentally match an unrelated range in the current module and return incorrect parent declarations. Consider only applying this override-redirect when definition.module.path() matches the current module, or resolve the correct handle/index for definition.module before consulting parent_methods_map.

[stroxler]

Thanks! I think there are at least four sets of concerns we need to address before we can merge this:

0. Design concern: the reused references index excludes library parents and several special methods. I confirmed that Sized.__len__ and a project-local __init__ override resolve to themselves. A dedicated ancestor lookup would avoid those limitations and avoid repurposing Go to Declaration for every LSP client.

1. Parent navigation can use offsets from the wrong document snapshot.
   [lsp.rs:5420–5431](https://github.com/meta/pyrefly/blob/64a316f1f08451e4a45d257c7aec7a35884746b7/pyrefly/lib/state/lsp.rs#L5420-L5431) selects whichever memory/filesystem counterpart appears first in an unordered handle list, then retains the original byte range. With CRLF disk contents and LF editor contents, my repro navigated to the s in self instead of f in 10/20 runs. Prefer the exact module snapshot; any counterpart fallback must reconcile the range.

2. [Routine CodeLens refreshes enqueue uncancellable workspace searches.
   [overrideCodeLens.ts:270–281](https://github.com/meta/pyrefly/blob/64a316f1f08451e4a45d257c7aec7a35884746b7/lsp/src/overrideCodeLens.ts#L270-L281) issues declaration and implementation requests for every method—even when none has overrides. A 200-method negative fixture generated 400 requests. Implementation searches traverse reverse dependencies on the shared heavy-task queue, and execute-provider commands do not propagate the lens cancellation token. Debouncing and the per-invocation worker limit don’t cancel obsolete work. Use a cancellable server-side CodeLens query, batching methods or resolving lazily.

3. Comment-section headings suppress otherwise-working lenses.
   [overrideCodeLens.ts:83–91](https://github.com/meta/pyrefly/blob/64a316f1f08451e4a45d257c7aec7a35884746b7/lsp/src/overrideCodeLens.ts#L83-L91) descends only through class symbols. Pyrefly nests classes under String symbols for headings such as # Models ----, so the entire subtree is skipped. The mocked-provider repro changes from one override lens to none when wrapped in a section. Traverse other container nodes while preserving class context.

[stroxler]

Looks like this needs a rebase before we can merge. The update addresses the original ancestor-lookup, snapshot-pairing, and comment-section concerns. Since we need an update anyway, here are a few more concerns worth looking into:

1. Rebase onto main and resolve the merge conflicts.

2. Avoid eagerly querying symbols for every navigation target.
   [overrideCodeLens.ts:280–301](https://github.com/meta/pyrefly/blob/3ec319ca6271b4bcdce1e9016966da26f288a7e9/lsp/src/overrideCodeLens.ts#L280-L301) requests document symbols for every implementation just to build lens labels. A mocked-provider repro generated one batch plus 500 symbol requests, all still pending after cancellation. Return display names in the batch, or defer multi-target naming until the user opens the quick-pick.

3. Refresh lenses when server state changes, and handle server cancellation.
   Background indexing and changes to subclass files can leave the base file’s lenses stale because they don’t trigger a refresh. Also, [overrideCodeLens.ts:255–259](https://github.com/meta/pyrefly/blob/3ec319ca6271b4bcdce1e9016966da26f288a7e9/lsp/src/overrideCodeLens.ts#L255-L259) rethrows server-initiated cancellation when the local token/version hasn’t changed, leaving lenses missing. Add server-driven invalidation and an appropriate cancellation/retry path.

4. Validate notebook requests against the correct version.
   [server.rs:6055–6058](https://github.com/meta/pyrefly/blob/3ec319ca6271b4bcdce1e9016966da26f288a7e9/pyrefly/lib/lsp/non_wasm/server.rs#L6055-L6058) compares the cell document’s version with the notebook’s version. A backend repro succeeds initially, then rejects the unchanged cell after a metadata-only notebook update. Track cell versions or explicitly send and validate the notebook version; add that regression test.

Optional, nonblocking optimization: cache the method lookup/remapping maps instead of rebuilding them for every reverse dependency, and skip candidates with empty parent maps.

[github-actions]

According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅