awesome_lints 2.2.0

Comprehensive custom lint rules for Dart and Flutter.

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

2.2.0 - 2025-12-24

Bug Fixes

• dispose_fields: Now correctly skips externally-owned resources (e.g., resources provided via constructor parameters that should not be disposed by the class)
• avoid_collection_equality_checks: Now properly skips null comparison checks (== null or != null)
• TypeCompatibilityChecker: Improved to support subtype relationship checks for more accurate type analysis
• newline_before_ rules*: Auto-fixes now correctly preserve code indentation
• Test fixtures: Corrected Provider API usage in dispose_fields test cases

Documentation

• COMMON_LINTS.md: Added comprehensive code examples for additional rules, improving developer guidance
• README.md: Added new "Enabling Individual Rules" section with clear examples of three approaches for configuring rules

Maintenance

• Removed unused test files
• Code formatting improvements

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2.1.0 - 2025-12-22

BREAKING CHANGES

Rules are now disabled by default (opt-in model)

Previous versions (v2.0.0 and earlier) enabled all 128 rules automatically. Starting with v2.1.0, rules must be explicitly enabled or configured via presets.

Migration Required:

To maintain v2.0.0 behavior (all rules enabled):

# analysis_options.yaml
include: package:awesome_lints/presets/strict.yaml

To adopt the recommended preset (recommended for most projects):

# analysis_options.yaml
include: package:awesome_lints/presets/recommended.yaml

For gradual adoption (core essential rules only):

# analysis_options.yaml
include: package:awesome_lints/presets/core.yaml

See Migration Guide for detailed instructions.

Features

New Preset Configurations:

• core.yaml - Essential rules only (~15 rules)

  • Critical bug prevention
  • Null safety issues
  • Flutter lifecycle errors
  • Recommended for new projects

• recommended.yaml - Balanced rule set (~40 rules)

  • Includes all core rules
  • Code quality improvements
  • Common mistake prevention
  • Recommended for most projects

• strict.yaml - All rules enabled (128 rules)

  • Maintains v2.0.0 behavior
  • Comprehensive analysis
  • Recommended for very strict projects

• Category-specific presets:

  • flutter.yaml - All 32 Flutter rules
  • common.yaml - All 65 common Dart rules
  • provider.yaml - All 8 Provider rules
  • bloc.yaml - All 22 Bloc rules
  • fake_async.yaml - All FakeAsync rules

Documentation

• Added comprehensive Migration Guide
• Updated README with preset usage examples
• Updated all category documentation files
• Added preset comparison guide

Migration Examples

Before (v2.0.0):

# All rules enabled by default
custom_lint:
  rules:
    - avoid_non_null_assertion: false  # Must disable unwanted
    - no_magic_number: false           # Must disable unwanted

After (v2.1.0):

# Use preset or enable specific rules
include: package:awesome_lints/presets/recommended.yaml

# Or enable specific rules only
custom_lint:
  enable_all_lint_rules: false
  rules:
    - avoid_late_context
    - prefer_early_return

---

2.0.0 - 2025-12-19

Major Release - Framework-Specific Lints

🎉 Major expansion with 42 new lint rules across three new categories: Bloc, Provider, and FakeAsync, plus 11 new common lint rules!

New Categories

Bloc Lints (22 rules)

Framework-specific lints for the Bloc state management library:

• avoid-bloc-public-fields - Warns when a Bloc or Cubit has public fields
• avoid-bloc-public-methods - Warns when a Bloc has public methods except overridden ones
• avoid-cubits - Warns when a Cubit is used
• avoid-duplicate-bloc-event-handlers - Detects multiple handlers for the same event
• avoid-empty-build-when - Requires buildWhen condition in BlocBuilder/BlocConsumer
• avoid-existing-instances-in-bloc-provider - Prevents reusing instances in BlocProvider
• avoid-instantiating-in-bloc-value-provider - Prevents new instances in BlocProvider.value
• avoid-passing-bloc-to-bloc - Prevents Bloc dependencies on other Blocs
• avoid-passing-build-context-to-blocs - Prevents BuildContext in Bloc events/methods
• avoid-returning-value-from-cubit-methods - Ensures Cubits communicate via state
• check-is-not-closed-after-async-gap - Requires isClosed checks in async handlers
• emit-new-bloc-state-instances - Prevents emitting existing state instances
• handle-bloc-event-subclasses - Ensures all event subclasses are handled
• prefer-bloc-event-suffix - Enforces "Event" suffix for event classes
• prefer-bloc-extensions - Suggests context.read()/watch() over BlocProvider.of()
• prefer-bloc-state-suffix - Enforces "State" suffix for state classes
• prefer-correct-bloc-provider - Ensures BlocProvider is used for Blocs
• prefer-immutable-bloc-events - Requires @immutable on Bloc events
• prefer-immutable-bloc-state - Requires @immutable on Bloc state
• prefer-multi-bloc-provider - Suggests MultiBlocProvider for nested providers
• prefer-sealed-bloc-events - Requires sealed/final modifiers on event classes
• prefer-sealed-bloc-state - Requires sealed/final modifiers on state classes

Provider Lints (8 rules)

Framework-specific lints for the Provider state management library:

• avoid-instantiating-in-value-provider - Prevents new instances in Provider.value
• avoid-read-inside-build - Warns about read() usage in build methods
• avoid-watch-outside-build - Warns about watch()/select() outside build
• dispose-providers - Ensures proper disposal of provided resources
• prefer-immutable-selector-value - Requires immutable values in Selector
• prefer-multi-provider - Suggests MultiProvider for nested providers
• prefer-nullable-provider-types - Recommends nullable provider types
• prefer-provider-extensions - Suggests context extensions over Provider.of()

FakeAsync Lints (1 rule)

Testing-focused lints for the fake_async package:

• avoid-async-callback-in-fake-async - Prevents async callbacks in FakeAsync

New Common Lints (11 rules)

Enhanced common lints with new best practice rules:

• prefer-async-await - Suggests async/await over Future API
• prefer-contains - Suggests contains() over indexOf() != -1
• prefer-correct-for-loop-increment - Validates for-loop increment expressions
• prefer-correct-json-casts - Ensures proper JSON type casting
• prefer-early-return - Recommends early returns to reduce nesting
• prefer-first - Suggests first over [0] or elementAt(0)
• prefer-iterable-of - Suggests Iterable.of() over manual iteration
• prefer-last - Suggests last over [length - 1]
• prefer-named-boolean-parameters - Requires named parameters for booleans
• prefer-return-await - Suggests explicit return await in try blocks
• prefer-switch-expression - Recommends switch expressions over statements

Documentation

• Added BLOC_LINTS.md with comprehensive Bloc lint documentation
• Added PROVIDER_LINTS.md with comprehensive Provider lint documentation
• Added FAKE_ASYNC_LINTS.md with FakeAsync lint documentation
• Updated test fixtures and configuration for new rules

Summary

Version 2.0.0 introduces:

• 42 new lint rules (22 Bloc + 8 Provider + 1 FakeAsync + 11 Common)
• 3 new framework-specific categories (Bloc, Provider, FakeAsync)
• Total of 128 lint rules across all categories
• Enhanced coverage for popular Flutter state management solutions
• Improved testing practices with FakeAsync support

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1.0.0 - 2025-12-19

Initial Release

🎉 First stable release of Awesome Lints - a comprehensive collection of custom lint rules for Dart and Flutter applications.

Flutter-Specific Lints (32 rules)

Widget Lifecycle & State Management:

• avoid-empty-setstate - Warns when setState is called with an empty callback
• avoid-late-context - Prevents context access in late field initializers
• avoid-mounted-in-setstate - Ensures mounted checks occur before setState calls
• avoid-stateless-widget-initialized-fields - Warns about non-constant field initialization in StatelessWidget
• avoid-unnecessary-overrides-in-state - Detects unnecessary method overrides in State classes
• avoid-unnecessary-stateful-widgets - Warns when StatefulWidget doesn't use state
• dispose-fields - Ensures proper disposal of disposable fields
• proper-super-calls - Validates lifecycle method super calls

Widget Building & Performance:

• avoid-missing-controller - Warns when text fields lack controllers or callbacks
• avoid-single-child-column-or-row - Detects unnecessary Column/Row with single child
• avoid-undisposed-instances - Warns about undisposed Disposable instances
• avoid-unnecessary-gesture-detector - Suggests lighter alternatives to GestureDetector
• avoid-wrapping-in-padding - Prevents unnecessary Padding wrappers
• pass-existing-future-to-future-builder - Prevents inline future creation in FutureBuilder
• pass-existing-stream-to-stream-builder - Prevents inline stream creation in StreamBuilder
• prefer-single-setstate - Recommends consolidating multiple setState calls

Widget Optimization:

• prefer-align-over-container - Suggests Align instead of Container for alignment-only
• prefer-center-over-align - Suggests Center instead of Align(alignment: Alignment.center)
• prefer-constrained-box-over-container - Suggests ConstrainedBox for constraints-only scenarios
• prefer-container - Suggests Container to replace nested containerizable widgets
• prefer-padding-over-container - Suggests Padding instead of Container for padding-only

Widget Best Practices:

• prefer-action-button-tooltip - Recommends tooltips for action buttons
• prefer-async-callback - Suggests AsyncCallback instead of Future
• prefer-compute-over-isolate-run - Recommends compute over Isolate.run
• prefer-dedicated-media-query-methods - Suggests specific MediaQuery methods
• prefer-for-loop-in-children - Suggests for-loops over .map().toList() in children
• prefer-sized-box-square - Suggests SizedBox.square() for square boxes
• prefer-sliver-prefix - Enforces "Sliver" prefix for sliver widgets
• prefer-spacing - Suggests spacing parameter over SizedBox (Flutter 3.27+)
• prefer-text-rich - Suggests Text.rich() over RichText
• prefer-void-callback - Suggests VoidCallback over void Function()
• prefer-widget-private-members - Recommends private members for widget internals

Common Dart Lints (54 rules)

Code Quality & Logic:

• arguments-ordering - Enforces named arguments in declaration order
• avoid-collapsible-if - Suggests combining nested if statements
• avoid-complex-arithmetic-expressions - Warns about overly complex arithmetic
• avoid-complex-conditions - Warns about complex conditional expressions
• avoid-complex-loop-conditions - Warns about complex loop conditions
• avoid-contradictory-expressions - Detects logical contradictions
• avoid-constant-assert-conditions - Warns about constant assert conditions
• avoid-constant-conditions - Warns about constant if/while conditions
• avoid-constant-switches - Warns about constant switch expressions
• binary-expression-operand-order - Enforces consistent operand ordering

Anti-Patterns & Potential Bugs:

• avoid-accessing-collections-by-constant-index - Suggests first/last over [0]/[length-1]
• avoid-accessing-other-classes-private-members - Prevents accessing private members
• avoid-always-null-parameters - Warns about parameters always passed as null
• avoid-assigning-to-static-field - Warns about static field mutation
• avoid-assignments-as-conditions - Prevents assignments in conditions
• avoid-async-call-in-sync-function - Warns about unawaited async calls
• avoid-bitwise-operators-with-booleans - Prevents & and | with booleans
• avoid-cascade-after-if-null - Warns about cascades after ?.
• avoid-collection-equality-checks - Warns about == on collections
• avoid-collection-methods-with-unrelated-types - Detects type mismatches in collection methods
• avoid-collection-mutating-methods - Warns about mutating immutable collections
• avoid-continue - Suggests alternatives to continue statements
• avoid-declaring-call-method - Warns about call method declarations
• avoid-non-null-assertion - Warns about ! operator usage

Type Safety:

• avoid-bottom-type-in-patterns - Prevents Never in patterns
• avoid-bottom-type-in-records - Prevents Never in records
• avoid-casting-to-extension-type - Warns about extension type casts
• no-object-declaration - Prevents Object type usage

Code Duplication & Redundancy:

• avoid-adjacent-strings - Warns about adjacent string literals
• avoid-conditions-with-boolean-literals - Prevents comparing with true/false
• avoid-duplicate-cascades - Detects duplicate cascade operations
• avoid-duplicate-collection-elements - Warns about duplicate collection elements
• no-boolean-literal-compare - Prevents explicit true/false comparisons
• no-equal-arguments - Detects identical arguments to different parameters
• no-equal-conditions - Warns about duplicate conditions in if-else chains
• no-equal-nested-conditions - Warns about redundant nested conditions
• no-equal-switch-case - Detects switch cases with identical bodies
• no-equal-switch-expression-cases - Warns about switch cases returning same value
• no-equal-then-else - Detects identical if-else branches

Code Style & Formatting:

• double-literal-format - Enforces consistent double literal formatting
• newline-before-case - Enforces blank lines before case clauses
• newline-before-constructor - Enforces blank lines before constructors
• newline-before-method - Enforces blank lines before methods
• newline-before-return - Enforces blank lines before return statements

Code Cleanliness:

• avoid-barrel-files - Warns about barrel file pattern
• avoid-commented-out-code - Detects commented-out code
• avoid-default-tostring - Warns about default toString() usage
• avoid-deprecated-usage - Warns about deprecated API usage
• avoid-double-slash-imports - Prevents // in import paths
• no-empty-block - Warns about empty code blocks
• no-empty-string - Warns about empty string usage

Resource Management:

• dispose-class-fields - Ensures disposal of disposable class fields

Magic Values:

• no-magic-number - Requires named constants for numeric literals
• no-magic-string - Requires named constants for repeated strings

Documentation

• Added comprehensive README.md with quick start guide
• Created FLUTTER_LINTS.md with detailed documentation for all Flutter rules
• Created COMMON_LINTS.md with detailed documentation for all common rules
• Each lint includes "Why?", "Bad", and "Good" examples

Features

• All lints enabled by default
• Support for custom_lint configuration
• Compatible with Dart 3.10.0+
• Compatible with Flutter 3.0.0+
• IDE integration (VS Code, Android Studio, IntelliJ)
• Watch mode support for continuous analysis

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Future Releases

Future releases will be documented here. We follow semantic versioning:

• MAJOR version for incompatible API changes
• MINOR version for new functionality in a backward compatible manner
• PATCH version for backward compatible bug fixes