Flutter Reference

Reference-count CodeLens above Dart declarations — like Visual Studio's "N references" hint above C# symbols — plus a workspace-wide scan for unused Dart files, assets, and pubspec.yaml dependencies.

Requires the Dart-Code extension (provides the language server this extension queries).

What it shows

Above every class / method / function / constructor / field / property / enum / enum member / interface / variable in your Dart code:

3 refs
Widget build(BuildContext context) { … }

Click the count to jump to a "Find All References" view of just the references this extension counts.

The lens deliberately ignores noise:

• Class ↔ constructor double-count is collapsed (both share the same name token, so a single Foo() call would otherwise count twice).
• Framework callbacks are excluded by default. References from the flutter and flutter_test packages aren't counted, so an @override Widget build(...) doesn't get inflated by Flutter SDK callsites.
• Doc-comment references can be skipped (/// See [build]) via a setting.

Commands

• Flutter Reference: Refresh — clear cache and recompute (useful after large refactors).

• Flutter Reference: Toggle On/Off — flip the lens without opening Settings.

• Flutter Reference: Find Unused Files, Assets & Dependencies — workspace-wide scan. For each Dart file under lib/, asset under assets/ (excluding assets/fonts/), and top-level dependency in pubspec.yaml, checks whether the basename / package name appears as a substring in any Dart file. Anything that doesn't is published as an Information diagnostic with the Unnecessary tag (struck-through in the editor) and listed in the Output channel.

  Any Dart file with a top-level main() is treated as an entrypoint and never reported.

Settings

Symbol kinds annotated are baked in: Class, Method, Function, Constructor, Field, Property, Enum, EnumMember, Interface, Variable.

How it works

• Registers a CodeLensProvider for language: dart.
• Pulls symbols via vscode.executeDocumentSymbolProvider (served by the Dart analyzer).
• For each symbol, queries vscode.executeReferenceProvider lazily in resolveCodeLens so off-screen lenses don't trigger work.
• Per-document lens cache (keyed by version, LRU-capped at 200) and a per-file line cache for the doc-comment filter (also LRU-capped at 200, invalidated on save).
• Package-name detection covers .pub-cache/hosted/<host>/<pkg>-<ver>/, .pub-cache/git/<pkg>-<hash>/, and flutter/packages/<pkg>/.

Caveats

• The CodeLens API only renders lens on open editors — close a file and its lens isn't computed. Use Find Unused Files for workspace-wide reporting.
• Reference lookups are O(symbols × analyzer round-trip). Large files may flash counts as lenses resolve.
• The first scan after opening a project can be slow while the Dart analyzer warms up — subsequent runs reuse its index.
• Package-name detection for excludePackages doesn't recognise path-based deps in arbitrary locations. If your refs live outside .pub-cache/ or the Flutter SDK, listing the package in excludePackages may have no effect.

Build from source

npm install
npm run compile
npx @vscode/vsce package
code --install-extension flutter-reference-0.1.0.vsix --force