Linter for Dart

A Dart style linter.

Installing

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

Alternatively, if you want to contribute to the linter or examine the source, clone the linter repo like this:

$ git clone https://github.com/dart-lang/linter.git

Usage

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

linter:
  rules:
    - annotate_overrides
    - hash_and_equals
    - prefer_is_not_empty

you could lint your package like this:

$ dartanalyzer --options analysis_options.yaml .

and see any violations of the annotate_overrides, hash_and_equals, and prefer_is_not_empty rules in the console. In practice you would probably configure quite a few more rules (the full list is here).

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

   // ignore: avoid_as
   (pm as Person).firstName = 'Seth'

tells the dartanalyzer to ignore this instance of avoid_as warning. 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:
    - avoid_as
analyzer:
  errors:
    avoid_as: error

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

Contributing

Feedback is, of course, 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 at the issue tracker.

0.1.33

Features

new prefer_const_constructors_in_immutables lint
new always_put_required_named_parameters_first lint
new prefer_asserts_in_initializer_lists lint
support for running in --benchmark mode
new prefer_single_quote_strings lint

Fixes

docs for avoid_setters_without_getters
fix to directives_ordering to work with part directives located after exports
fixes to cascade_invocations false positives
fixes to literal_only_boolean_expressions false positives
fix to ensure cascade_invocations only lints method invocations if target is a simple identifier
fixes to use_string_buffers false positives
fixes to prefer_const_constructors

0.1.32

Lint stats (-s) output now sorted.

0.1.31

New prefer_foreach lint.
New use_string_buffers rule.
New unnecessary_overrides rule.
New join_return_with_assignment_when_possible rule.
New use_to_and_as_if_applicable rule.
New avoid_setters_without_getters rule.
New always_put_control_body_on_new_line rule.
New avoid_positional_boolean_parameters rule.
New always_require_non_null_named_parameters rule.
New prefer_conditional_assignment rule.
New avoid_types_on_closure_parameters rule.
New always_put_control_body_on_new_line rule.
New use_setters_to_change_properties rule.
New avoid_returning_this rule.
New avoid_annotating_with_dynamic_when_not_required rule.
New prefer_constructors_over_static_methods rule.
New avoid_returning_null rule.
New avoid_classes_with_only_static_members rule.
New avoid_null_checks_in_equality_operators rule.
New avoid_catches_without_on_clauses rule.
New avoid_catching_errors rule.
New use_rethrow_when_possible rule.
Many lint fixes (notably prefer_final_fields, unnecessary_lambdas, await_only_futures, cascade_invocations, avoid_types_on_closure_parameters, and overridden_fields).
Significant performance improvements for prefer_interpolation_to_compose_strings.
New unnecessary_this rule.
New prefer_initializing_formals rule.

0.1.30

New avoid_function_literals_in_foreach_calls lint.
New avoid_slow_async_io lint.
New cascade_invocations lint.
New directives_ordering lint.
New no_adjacent_strings_in_list lint.
New no_duplicate_case_values lint.
New omit_local_variable_types lint.
New prefer_adjacent_string_concatenation lint.
New prefer_collection_literals lint.
New prefer_const_constructors lint.
New prefer_contains lint.
New prefer_expression_function_bodies lint.
New prefer_function_declarations_over_variables lint.
New prefer_initializing_formals lint.
New prefer_interpolation_to_compose_strings lint.
New prefer_is_empty lint.
New recursive_getters lint.
New unnecessary_brace_in_string_interps lint.
New unnecessary_lambdas lint.
New unnecessary_null_aware_assignments lint.
New unnecessary_null_in_if_null_operators lint.
Miscellaneous bug fixes and codegen improvements.

0.1.29

New cascade_invocations lint.
Expand await_only_futures to accept classes that extend or implement Future.
Improve camel case regular expression tests to accept $s.
Fixes to parameter_assignments (improved getter handling and an NPE).

0.1.27

Fixed cast exception in dart_type_utilities (dart-lang/sdk#27405).
New parameter_assignments lint.
New prefer_final_fields lint.
New prefer_final_locals lint.
Markdown link fixes in docs (#306).
Miscellaneous solo test running fixes and introduction of solo_debug (#304).

0.1.26

Updated tests to use package test (#302).

0.1.25

Fixed false positive on []= in always_declare_return_types (#300).
New invariant_booleans lint.
New literal_only_boolean_expressions lint.
Fixed camel_case_types to allow $ in identifiers (#290).

0.1.24

Internal updates to keep up with changes in the analyzer package.
Updated close_sinks to respect calls to destroy (#282).
Fixed only_throw_errors to report on the expression not node.

0.1.23

Removed whitespace_around_ops pending re-name and re-design (#249).

0.1.22

Grinder support (rule:rule_name and docs:location) for rule stub and doc generation (respectively).
Fix to allow leading underscores in non_constant_identifier_names.
New valid_regexps lint (#277).
New whitespace_around_ops lint (#249).
Fix to overridden_fields to flag overridden static fields (#274).
New list_remove_unrelated_type to detect passing a non-T value to `List.remove()`` (#271).
New empty_catches lint to catch empty catch blocks (#43).
Fixed close_sinks false positive (#268).
linter support for --strong to allow for running linter in strong mode.

0.1.21

New only_throw_errors lint.
New lint to check for empty_statements (#259).
Fixed NSME when file contents cannot be read (#260).
Fixed unsafe cast in iterable_contains_unrelated_type (#267).

0.1.20

New cancel_subscriptions lint.

0.1.19

New close_sinks lint.
Fixes to iterable_contains_unrelated_type.

0.1.18

Fix NSME in iterable_contains_unrelated_type (#245).
Fixed typo in comment_references error description.
Fix overriden_field false positive (#246).
Rename linter binary lints option to rules (#248).
Help doc tweaks.

0.1.17

Fix to public_member_api_docs to check for documented getters when checking setters (#237).
New iterable_contains_unrelated_type lint to detect when Iterable.contains is invoked with an object of an unrelated type.
New comment_references lint to ensure identifiers referenced in docs are in scope (#240).

0.1.16

Fix for false positive in overriden_fields.
New unrelated_type_equality_checks lint.
Fix to accept $ identifiers in string interpolation lint (#214).
Update to new plugin API (0.2.0).
Strong mode cleanup.

0.1.15

Fix to allow simple getter/setters when a decl is ``@protected` (#215).
Fix to not require type params in is checks (#227).
Fix to not flag field formal identifiers in parameters (#224).
Fix to respect filters when calculating error codes (#198).
Fix to allow const and final vars to be initialized to null (#210).
Fix to respect commented blocks in empty_constructor_bodies (#209).
Fix to check types on list/map literals (#199).
Fix to skip main when checking for API docs (#207).
Fix to allow leading $ in type names (#220).
Fix to ignore private typedefs when checking for types (#216).
New test_types_in_equals lint.
New await_only_futures lint.
New throw_in_finally lint.
New control_flow_in_finally lint.

0.1.14

Fix to respect @optionalTypeArgs (#196).
Lint to warn if a field overrides or hides other field.
Fix to allow single char UPPER_CASE non-constants (#201).
Fix to accept casts to dynamic (#195).

0.1.13

Fix to skip overriding members in API doc checks (public_member_api_docs).
Fix to suppress lints on synthetic nodes/tokens (#193).
Message fixes (annotate_overrides, public_member_api_docs).
Fix to exclude setters from return type checks (#192).

0.1.12

Fix to address LibraryNames regexp that in pathological cases went exponential.

0.1.11

Doc generation improvements (now with options samples).
Lint to sort unnamed constructors first (#187).
Lint to ensure public members have API docs (#188).
Lint to ensure constructors are sorted first (#186).
Lint for hashCode and == (#168).
Lint to detect un-annotated overrides (#167).
Fix to ignore underscores in public APIs (#153).
Lint to check for return types on setters (#122).
Lint to flag missing type params (#156).
Lint to avoid inits to null (#160).

0.1.10

Updated to use analyzer 0.27.0.
Updated options processing to handle untyped maps (dart-lang/sdk#25126).

0.1.9

Fix type_annotate_public_apis to properly handle getters/setters (#151; dart-lang/sdk#25092).

0.1.8

Fix to protect against errors in linting invalid source (dart-lang/sdk#24910).
Added avoid_empty_else lint rule (dart-lang/sdk#224936).

0.1.7

Fix to package_api_docs (dart-lang/sdk#24947; #154).

0.1.6

Fix to package_prefixed_library_names (dart-lang/sdk#24947; #154).

0.1.5

Added prefer_is_not_empty lint rule (#143).
Added type_annotate_public_apis lint rule (#24).
Added avoid_as lint rule (#145).
Fixed non_constant_identifier_names rule to special case underscore identifiers in callbacks.
Fix to escape _s in callback type validation (addresses false positives in always_specify_types) (#147).

0.1.4

Added always_declare_return_types lint rule (#146).
Improved always_specify_types to detect missing types in declared identifiers and narrowed source range to the token.
Added implementation_imports lint rule (#33).
Test performance improvements.

0.1.3+5

Added always_specify_types lint rule (#144).

0.1.3+4

Fixed linter registry memory leaks.

0.1.3

Fixed various options file parsing issues.

0.1.2

Fixed false positives in unnecessary_brace_in_string_interp lint. Fix #112.

0.1.1

Internal code and dependency constraint cleanup.

0.1.0

Initial stable release.

0.0.2+1

Added machine output option. Fix #69.
Fixed resolution of files in lib/ to use a package: URI. Fix #49.
Tightened up analyzer package constraints.
Fixed false positives in one_member_abstracts lint. Fix #64.

0.0.2

Initial push to pub.

1. Depend on it

Add this to your package's pubspec.yaml file:

dependencies:
  linter: "^0.1.33"

2. Install it

You can install packages from the command line:

$ pub get

Alternatively, your editor might support 'pub get'. Check the docs for your editor to learn more.

Version	Uploaded	Documentation	Archive
0.1.33	Jul 17, 2017
0.1.31	May 8, 2017
0.1.30	Apr 7, 2017
0.1.29	Nov 14, 2016
0.1.28	Oct 12, 2016
0.1.27	Sep 23, 2016
0.1.26	Sep 5, 2016
0.1.25	Sep 5, 2016
0.1.24	Aug 15, 2016
0.1.23	Jul 28, 2016

All 40 versions...

About

Style linter for Dart.

Author

Dart Team

Uploader

pquitslund@google.com
brianwilkerson@google.com
kevmoo@google.com
devoncarew@google.com

linter 0.1.33