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
| Setting |
Type |
Default |
Description |
flutterReference.enabled |
boolean |
true |
Toggle the lens. |
flutterReference.filterDocComments |
boolean |
false |
Skip references on /// documentation-comment lines. |
flutterReference.excludePackages |
string[] |
["flutter", "flutter_test"] |
Packages whose references are not counted. Use the special value "all" to exclude every reference outside lib/. |
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
