meta 1.2.2

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This library contains the declarations of annotations that developers can use to express the intentions that otherwise can't be deduced by statically analyzing the source code. These annotations are i

1.2.2 #

  • Removed unawaited because the attempt to move it from package:pedantic caused too many issues. If you see errors about unawaited being declared in two places, please update the version constraints for meta to 1.2.2 or 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 @doNotStore to annotate methods, getters and functions to indicate that values obtained by invoking them should not be stored in a field or top-level variable.
  • Introduce unawaited to mark invocations that return a Future where it's intentional that the future is not being awaited. (Moved from package:pedantic.)

1.1.8 #

  • Introduce @nonVirtual to annotate instance members that should not be overridden in subclasses or when mixed in.

1.1.7 #

  • Introduce @sealed to 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 @sealed may 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 @alwaysThrows to 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);
          return True;
      void failBigTime(expected, actual) {
        throw new StateError('Expected $expected, but was $actual.');

1.0.5 #

  • Introduce @experimental to 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 @virtual to 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 @checked to 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 @visibleForTesting annotation for declarations that may be referenced only in the library or in a test.

1.0.1 #

  • Updated @factory to allow statics and methods returning null.

1.0.0 #

  • First stable API release.

0.12.2 #

  • Updated @protected to include implemented interfaces (linter#252).

0.12.1 #

  • Fixed markdown in dartdocs.

0.12.0 #

  • Introduce @optionalTypeArgs annotation for classes whose type arguments are to be treated as optional.

0.11.0 #

  • Added new Required constructor with a means to specify a reason to explain why a parameter is required.

0.10.0 #

  • Introduce @factory annotation for methods that must either be abstract or must return a newly allocated object.
  • Introduce @literal annotation that indicates that any invocation of a constructor must use the keyword const unless one or more of the arguments to the constructor is not a compile-time constant.

0.9.0 #

  • Introduce @protected annotation for members that must only be called from instance members of subclasses.
  • Introduce @required annotation for optional parameters that should be treated as required.
  • Introduce @mustCallSuper annotation for methods that must be invoked by all overriding methods.
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This library contains the declarations of annotations that developers can use to express the intentions that otherwise can't be deduced by statically analyzing the source code. These annotations are intended to be used by tools to provide a better user experience.

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