# Static Analysis, Lints and Formatting — Dart

Source: https://www.skillbyai.com/en/dart/t-quality

> Configure analysis_options.yaml, apply lints and automate fixes.

## Quality checks built in

Dart's **analyser** runs continuously in your editor and with `dart analyze`, reporting type errors, null-safety problems and **lints**. Configure it in **`analysis_options.yaml`**: include a recommended rule set (**`package:lints/recommended.yaml`** for Dart, **`package:flutter_lints/flutter.yaml`** for Flutter), enable stricter **language modes** (`strict-casts`, `strict-inference`, `strict-raw-types`), and enable or disable individual lint rules such as `unawaited_futures`, `prefer_const_constructors`, `avoid_print` and `require_trailing_commas`. **`dart fix --apply`** applies automated fixes suggested by the analyser, including migrations for deprecated APIs. **`dart format`** enforces the official style with no configuration debates (apart from page width), and recent versions use a "tall" style with trailing commas managed automatically. Treat warnings as errors in CI with `dart analyze --fatal-infos` or `--fatal-warnings`. Code generation tools (`build_runner` with `json_serializable` or `freezed`) generate boilerplate such as JSON methods and copyWith; keep generated files out of manual edits and regenerate them in the build.

## A strict analysis_options.yaml

Recommended lints plus stricter type checks and a few extra rules.

```yaml
include: package:lints/recommended.yaml

analyzer:
  language:
    strict-casts: true
    strict-inference: true
    strict-raw-types: true
  exclude:
    - "**/*.g.dart"
    - "**/*.freezed.dart"

linter:
  rules:
    - unawaited_futures
    - prefer_final_locals
    - prefer_const_constructors
    - avoid_dynamic_calls
    - always_declare_return_types

# CI:
#   dart format --output=none --set-exit-if-changed .
#   dart analyze --fatal-infos
#   dart test
```

## A strict but helpful editor

The analyser is an editor who reads every sentence as you type and circles mistakes before anyone else sees them. Stricter settings mean more red ink at first, but far fewer embarrassing errors in print.

**Quiz:** Which command applies automated fixes suggested by the Dart analyser?

- [ ] dart format
- [ ] dart pub upgrade
- [ ] dart compile
- [x] dart fix --apply

*Answer:* dart fix --apply. dart fix applies analyser-provided fixes, including API migrations.