Advanced linter
for Flutter and Dart

DCM helps your team move faster by unifying code style, reducing the time spent on code reviews, onboarding new team members, and finding and fixing tricky bugs.

Analyze

DCM is a tool to build maintainable software faster. It provides you with valuable insights that you didn't know about before. No AI hallucinations, purely statically available data that would take too long to collect manually.

1class _MyState extends State<MyWidget> {
2  @override
3  Widget build(BuildContext context) {
4    setState(() {
5      myState = "Hello, Flutter!";
6    });
7
8    return Text(myState);
9  }
10}

Lint rules

Find bugs and style issues. Reduce routine.

Metrics:

NOM: 2 methods, violation level: below

CYCLO: 1, violation level: below

1
2  
3  
4class MyCustomWidget extends StatefulWidget {
5  const MyCustomWidget({
6    super.key,
7    this.child,
8    this.titleBar,
9    this.sidebar,
10

Metrics

Get your projects complexity overview

MyCustomWidget statefulWidget

Quality score: 93% High quality

Used widgets: 1 distinct, 1 total

Builder, 1 reference flutterOpen in VS Code Open GitHub Open Flutter docs

Similar widgets: 1

55% of widget tree matches 55% OtherWidget widget tree

Widget analysis

Ensure the highest quality of your widgets

$: dcm analyze-assets lib

assets/app-logo.png (2.41 KB, 204 x 27):
  ✘ this image name is in kebab-case. Try
    renaming it to snake_case.
  ✘ this image size exceeds the 1KB limit.
  ✘ incorrect image format (.png). Convert
    this image to webp to reduce its size.

Image assets analysis

Keep your "assets" folder maintainable

part_file.dart

main_file.dart

another_file.dart

Project structure analysis

Quickly find how files depend on each other

Fix

DCM comes with powerful fixes that you can apply from both your favorite IDE and CLI. Violation preview helps you quickly choose new rules and find fixable issues that you can address right away. Everything to make you more productive.

Quick Fix...
Move first
Ignore proper-super-calls for this line
Ignore proper-super-calls for the entire file
Fix all auto-fixable problems
Fix all proper-super-calls problems

IDE quick fixes

Automatically fix highlighted fixable issues

$: dcm fix lib

Calculating fixes... 

✅ Calculation is completed.
   Applying the results.

CLI fixes

The fastest way to update your whole project

$: dcm init preview lib

/path/to/package:
  rules:
    - dispose-fields # 3 violations
    - arguments-ordering # 2 violations
    - prefer-trailing-comma # 1 violation
    - avoid-unused-parameters # 1 violation

Violations preview

Your assistant in choosing new rules

Maintain

One way to move faster is to timely remove anything that slows you down in the long run. On top of that, removing unused code, files and localization helps you find unintentionally unused parts that are actually bugs.

$: dcm check-unused-code lib

lib/main.dart:
  ✘ unused function someFunction
    at /path/to/file.dart:4:1
  ✘ unused top level variable someVar
    at /path/to/file.dart:6:1

Unused code detection

Clean up with little effort

$: dcm check-unused-files lib

lib/main.dart:
  ✘ unused file
    at /path/to/file.dart:4:1
  ✘ used only in tests 
    at /path/to/file.dart:6:1

Unused files detection

Throw away entire files? Why not

$: dcm check-parameters lib

lib/main.dart:
  ✘ method someMethod
    has parameter issues
    - (String? value) is unnecessary nullable
      at /path/to/file.dart:4:1

Parameter issues detection

Simplify the inputs of your functions

$: dcm check-unused-l10n lib

class HomeI18n
  ✘ unused getter homeTab
    at /path/to/file.dart:4:1
  ✘ unused getter profileTab
    at /path/to/file.dart:6:1

Unused localization detection

Reduce your app bundle

$: dcm check-dependencies lib

pubspec.yaml:
  ✘ cupertino_icons is not used.
    at /path/to/pubspec.yaml:4:1
  ✘ lints should be listed in dev dependencies.
    at /path/to/pubspec.yaml:6:1

Misused dependencies detection

Timely remove unused external packages

$: dcm check-code-duplication lib

lib/main.dart:
  ✘ method someMethod
    has 1 duplicate declaration:
    - method anotherMethod
      at /path/to/another_file.dart:6:1

Duplicate code detection

Easily find unwanted duplications

Configure

DCM is designed with your needs in mind. There is no code style that suits everyone. Choose the rules and metrics that will help you, and customize them so that they help you as effectively as possible.

analyzer:
  exclude:
    - build/**

dart_code_metrics:
  rules:
    - avoid-unused-parameters
    - avoid-undisposed-instances

Familiar configuration file

Configuration that is easy to use

dart_code_metrics:
  extends:
    - recommended
    - package:dart_code_metrics_presets/bloc.yaml
  rules:
    - no-empty-blocks: false
    - avoid-shadowing:
        ignore-static: true

Presets

Get started quickly and always stay up to date

"lib/main.dart": {
  "prefer-match-file-name": [
    "9075e416a7d67c2f6c7d9386dff2e591"
  ],
  "avoid-unused-parameters": [
    "808e0f8c9e3bc117072eebf4a25d51b6",
  ]
}

Baseline

Add to existing projects with ease

Integrate

DCM provides extensions for the most popular IDEs used by Dart and Flutter developers so you can get real-time feedback on code changes. And various CLI output formats and integrations provide the ultimate CI/CD experience.