Files
sdk/pkg/linter
Robert Nystrom 8ed0065bf6 Clean up the prefer_initializing_formals lint.
I started adding support for private named parameters to the lint, but
ran into a bunch of issues. I decided to sort those out in a separate
change (this one) before adding more functionality. This change:

* Removes dead code that was never reachable.

* Adds tests for implemented behavior that had no test coverage.

* Adds 20 lines of docs.

* Fixes a bug where the lint would erroneously fire if you assign to a
  static field.

* Gets the behavior working where the lint doesn't fire if there are
  multiple initializers for the same parameter. That behavior was
  implemented and then silently broken at some point in the past.

* Adds tests for that so that it doesn't get broken again.

* Generally reorganizes and rewrites the code.

Even with 20 lines of docs and a couple of bug fixes, it's 11 lines
shorter than it was before. It needed some love!

Change-Id: I8fbfb8071f0dc32c57b8d0ae0a0eb7c76bb0c307
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/471642
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
2026-01-12 13:46:33 -08:00
..
2025-03-31 09:46:29 -07:00
2026-01-07 08:21:43 -08:00

Linter for Dart

The Dart Linter package defines lint rules that identify and report on "lints" found in Dart code. Linting is performed by the Dart analysis server and the dart analyze command in the Dart command-line tool.

Installing

The linter is bundled with the Dart SDK; if you have an updated Dart SDK already, you're done!

Usage

The linter gives you feedback to help you catch potential errors and keep your code in line with the published Dart Style Guide. Enforceable lint rules (or "lints") are cataloged here and can be configured via an analysis options file. The linter is run from within the dart analyze command-line tool shipped with the Dart SDK. Assuming you have lints configured in an analysis_options.yaml file at the root of your project with these contents:

linter:
  rules:
    - annotate_overrides
    - hash_and_equals
    - prefer_is_not_empty

you could lint your package like this:

$ dart analyze .

and see any violations of the annotate_overrides, hash_and_equals, and prefer_is_not_empty rules in the console. To help you choose the rules you want to enable for your package, we have provided a complete list of rules with lints recommended by the Dart team collected in package:lints. Lints recommended for Flutter apps, packages, and plugins are documented in package:flutter_lints.

If a specific lint warning should be ignored, it can be flagged with a comment. For example,

   // ignore: camel_case_types
   class whyOhWhy { }

tells the Dart analyzer to ignore this instance of the camel_case_types warning.

End-of-line comments are supported as well. The following communicates the same thing:

   class whyOhWhy { // ignore: camel_case_types

To ignore a rule for an entire file, use the ignore_for_file comment flag. For example,

// ignore_for_file: camel_case_types

...

class whyOhWhy { }

tells the Dart analyzer to ignore all occurrences of the camel_case_types warning in this file.

As lints are treated the same as errors and warnings by the analyzer, their severity can similarly be configured in an options file. For example, an analysis options file that specifies

linter:
  rules:
    - camel_case_types
analyzer:
  errors:
    camel_case_types: error

tells the analyzer to treat camel_case_types lints as errors. For more on configuring analysis see the analysis option file docs.

Contributing

Feedback is greatly appreciated and contributions are welcome! Please read the contribution guidelines; mechanics of writing lints are covered here.

Features and bugs

Please file feature requests and bugs in the issue tracker.