meta
v1.16.0Annotations used to express developer intentions that can't otherwise be deduced by statically analyzing source code.
Package archive: https://pubdev.letsnova.ru/api/archives/meta/1.16.0.tar.gz
dart pub add metaReadme
This package defines annotations that can be used by the tools that are shipped with the Dart SDK.
Library Structure
The annotations in this package are defined in two libraries.
The library in meta.dart defines annotations that can be used by static
analysis tools to provide a more complete analysis of the code that uses them.
Within the SDK, these tools include the command-line analyzer (dart analyze)
and the analysis server that is used to power many of the Dart-enabled
development tools.
The library in dart2js.dart defines annotations that provide hints to dart2js
to improve the quality of the JavaScript code that it produces. These
annotations are currently experimental and might be removed in a future version
of this package.
Support
Post issues and feature requests on the GitHub issue tracker.
Questions and discussions are welcome at the Dart Analyzer Discussion Group.
License
See the LICENSE file.
Changelog
1.16.0
-
Add
TargetKinds to a few annotations to match custom-wired behavior that the Dart analyzer has been providing:- Require that
@factoryis only used on methods. - Require that
@Immutableis only used on classes, extensions, and mixins. - Require that
@mustBeOverriddenand@mustCallSuperare only used on overridable members. - Require that
@sealedis only used on classes.
- Require that
-
Updated
@doNotSubmitto (1) disallow same-library access (unlike other visibility annotation), (2) allow parameters marked with@doNotSubmitto be used in nested functions, and (3) disallowed@doNotSubmiton required parameters:import 'package:meta/meta.dart'; @doNotSubmit void a() {} void b() { // HINT: invalid_use_of_do_not_submit: ... a(); }import 'package:meta/meta.dart'; void test({ @doNotSubmit bool solo = false }) { void nested() { // OK if (solo) { /*...*/ } } }import 'package:meta/meta.dart'; void test({ // HINT: Cannot use on required parameters. @doNotSubmit required bool solo }) {}See https://github.com/dart-lang/sdk/issues/55558 for more information.
-
TargetKind.parameteris now allowed on a representation type, such as:// Ok, because `int _actual` is similar to a parameter declaration. extension type const FancyInt(@mustBeConst int _actual) {} -
Renamed
@ResourceIdentifierto@RecordUse.
1.15.0
-
Updated
@mustBeOverriddento only flag missing overrides in concrete classes; in other words, abstract classes (including implicitly abstract, i.esealed) and mixin declarations are no longer required to provide an implementation:import 'package:meta/meta.dart'; abstract class Base { @mustBeOverridden void foo() {} } class Derived extends Base { // ERROR: Missing implementation of `foo`. } abstract class Abstract extends Base { // No error. } sealed class Sealed extends Base { // No error. } mixin Mixin on Base { // No error. }See https://github.com/dart-lang/sdk/issues/52965 for more information.
-
Introduce
TargetKind.optionalParameter, to indicate that an annotation is valid on any optional parameter declaration. -
Introduce
TargetKind.overridableMember, to indicate that an annotation is valid on any instance member declaration. -
Introduce
TargetKind.instanceMember, to indicate that an annotation is valid on any instance member declaration. -
Updated
@doNotSubmitto (1) disallow same-library access (unlike other visibility annotation), (2) allow parameters marked with@doNotSubmitto be used in nested functions, and (3) disallowed@doNotSubmiton required parameters:import 'package:meta/meta.dart'; @doNotSubmit void a() {} void b() { // HINT: invalid_use_of_do_not_submit: ... a(); }import 'package:meta/meta.dart'; void test({ @doNotSubmit bool solo = false }) { void nested() { // OK if (solo) { /*...*/ } } }import 'package:meta/meta.dart'; void test({ // HINT: Cannot use on required parameters. @doNotSubmit required bool solo }) {}See https://github.com/dart-lang/sdk/issues/55558 for more information.
1.14.0
-
Introduce
TargetKind.constructor, to indicate that an annotation is valid on any constructor declaration. -
Introduce
TargetKind.directive, to indicate that an annotation is valid on any directive. -
Introduce
TargetKind.enumValue, to indicate that an annotation is valid on any enum value declaration. -
Introduce
TargetKind.typeParameter, to indicate that an annotation is valid on any type parameter declaration. -
Introduce
@doNotSubmitto annotate members that should not be accessed in checked-in code, typically because they are intended to be used ephemerally during development.One example is
package:test'ssolo: ...parameter, which skips all other tests in a test suite when set totrue. This parameter is useful during development, but should be prevented from being submitted:import 'package:meta/meta.dart'; void test( String name, void Function() body, { @doNotSubmit bool solo = false }) { // ... }import 'package:test/test.dart'; void main() { test( 'my test', () { // ... }, // HINT: invalid_use_of_do_not_submit: ... solo: true, ); } -
Introduce
@mustBeConstto annotate parameters which only accept constant arguments.
1.13.0
- Add type checks for the
@ResourceIdentifierexperimental annotation.
1.12.0
- Introduce the
@ResourceIdentifierexperimental annotation for static methods whose constant literal arguments should be collected during compilation. - Indicate that
@requiredand@Requiredare set to be deprecated for later removal.
1.11.0
- Introduce
TargetKind.extensionTypeto indicate that an annotation is valid on any extension type declaration.
1.10.0
- Introduce
@redeclareto annotate extension type members that redeclare members from a superinterface. - Migrate the
TargetKindenum to a class to ease the addition of new kinds.
1.9.1
- Update SDK constraints to
>=2.12.0 <4.0.0. - Mark
@reopenstable.
1.9.0
- Introduce
@reopento annotate class or mixin declarations that can safely extend classes markedbase,finalorinterface. - Introduce
@MustBeOverriddento annotate class or mixin members which must be overridden in all subclasses. - Deprecate
@alwaysThrows, which can be replaced by using a return type of 'Never'.
1.8.0
- Add
@UseResult.unless. - The mechanism behind
noInlineandtryInlinefromdart2js.darthas been changed. This should not affect the use of these annotations in practice.
1.7.0
- Restore
TargetKindExtensionandget displayString. We publishedanalyzer 1.7.2that is compatible withTargetKindExtension.
2.0.0 - removed
- Restore
TargetKindExtensionandget displayString.
1.6.0
- Remove
TargetKindExtension. Adding it was a breaking change, because there are clients, e.g.analyze 1.7.0, that also declare an extension onTargetKind, and also declareget displayString. This causes a conflict.
1.5.0
- Add
TargetKindExtension.displayString.
1.4.0
- Introduce
TargetKind.topLevelVariablethat indicates that an annotation is valid on any top-level variable declaration. - Introduce
@useResultto annotate methods, fields, or getters that return values that should be used - stored, passed as arguments, etc. - Updates for documentation.
1.3.0
- Stable release for null safety.
1.3.0-nullsafety.6
- Update SDK constraints to
>=2.12.0-0 <3.0.0based on beta release guidelines.
1.3.0-nullsafety.5
- Allow prerelease versions of the
2.12SDK.
1.3.0-nullsafety.4
- Introduce
@internalto annotate elements that should not be used outside of the package in which the element is declared.
1.3.0-nullsafety.3
- Allow 2.10 stable and 2.11.0 dev SDK versions.
1.3.0-nullsafety.2
- Update for the 2.10 dev SDK.
1.3.0-nullsafety.1
- Allow the <=2.9.10 stable SDK.
1.3.0-nullsafety
- Opt into null safety.
1.2.2
- Removed
unawaitedbecause the attempt to move it frompackage:pedanticcaused too many issues. If you see errors aboutunawaitedbeing declared in two places, please update the version constraints formetato1.2.2or later.
1.2.1
- Fixed a bug by adding an import of dart:async so that the code really is compatible with the lower bound of the SDK constraints.
1.2.0
- Introduce
unawaitedto mark invocations that return aFuturewhere it's intentional that the future is not being awaited. (Moved frompackage:pedantic.) - Introduce
@doNotStoreto annotate methods, getters and functions to indicate that values obtained by invoking them should not be stored in a field or top-level variable.
1.1.8
- Introduce
@nonVirtualto annotate instance members that should not be overridden in subclasses or when mixed in.
1.1.7
-
Introduce
@sealedto declare that a class or mixin is not allowed as a super-type.Only classes in the same package as a class or mixin annotated with
@sealedmay extend, implement or mix-in the annotated class or mixin. (SDK issue 27372).
1.1.6
- Set max SDK version to <3.0.0.
1.1.5
- Introduce @isTest and @isTestGroup to declare a function that is a test, or a test group.
1.1.4
- Added dart2js.dart.
1.1.2
- Rollback SDK constraint update for 2.0.0. No longer needed.
1.1.1
- Update SDK constraint to be 2.0.0 dev friendly.
1.1.0
-
Introduce
@alwaysThrowsto declare that a function always throws (SDK issue 17999). This is first available in Dart SDK 1.25.0-dev.1.0.import 'package:meta/meta.dart'; // Without knowing that [failBigTime] always throws, it looks like this // function might return without returning a bool. bool fn(expected, actual) { if (expected != actual) failBigTime(expected, actual); else return True; } @alwaysThrows void failBigTime(expected, actual) { throw new StateError('Expected $expected, but was $actual.'); }
1.0.5
- Introduce
@experimentalto annotate a library, or any declaration that is part of the public interface of a library (such as top-level members, class members, and function parameters) to indicate that the annotated API is experimental and may be removed or changed at any-time without updating the version of the containing package, despite the fact that it would otherwise be a breaking change.
1.0.4
-
Introduce
@virtualto allow field overrides in strong mode (SDK issue 27384).import 'package:meta/meta.dart' show virtual; class Base { @virtual int x; } class Derived extends Base { int x; // Expose the hidden storage slot: int get superX => super.x; set superX(int v) { super.x = v; } }
1.0.3
-
Introduce
@checkedto override a method and tighten a parameter type (SDK issue 25578).import 'package:meta/meta.dart' show checked; class View { addChild(View v) {} } class MyView extends View { // this override is legal, it will check at runtime if we actually // got a MyView. addChild(@checked MyView v) {} } main() { dynamic mv = new MyView(); mv.addChild(new View()); // runtime error }
1.0.2
- Introduce
@visibleForTestingannotation for declarations that may be referenced only in the library or in a test.
1.0.1
- Updated
@factoryto allow statics and methods returningnull.
1.0.0
- First stable API release.
0.12.2
- Updated
@protectedto include implemented interfaces (linter#252).
0.12.1
- Fixed markdown in dartdocs.
0.12.0
- Introduce
@optionalTypeArgsannotation for classes whose type arguments are to be treated as optional.
0.11.0
- Added new
Requiredconstructor with a means to specify a reason to explain why a parameter is required.
0.10.0
- Introduce
@factoryannotation for methods that must either be abstract or must return a newly allocated object. - Introduce
@literalannotation that indicates that any invocation of a constructor must use the keywordconstunless one or more of the arguments to the constructor is not a compile-time constant.
0.9.0
- Introduce
@protectedannotation for members that must only be called from instance members of subclasses. - Introduce
@requiredannotation for optional parameters that should be treated as required. - Introduce
@mustCallSuperannotation for methods that must be invoked by all overriding methods.
