## 1.17.0

- Introduce `@awaitNotRequired` to annotate `Future`-returning functions and
  `Future`-typed fields and top-level variables whose value does not
  necessarily need to be awaited. This annotation can be used to suppress
  `unawaited_futures` and `discarded_futures` lint diagnostics at call sites.

  For example, this `log` function returns a `Future`, but maybe the return
  value is typically not important, and is only useful in tests or while
  debugging:

  ```dart
  @awaitNotRequired Future<LogMessage> log(String message) { ... }

  void fn() {
    log('Message'); // Not important to wait for logging to complete.
  }
  ```

  Without the annotation on `log`, the analyzer may report a lint diagnostic at
  the call to `log`, such as `unawaited_futures` or `discarded_futures`
  regarding the danger of not awaiting the function call, depending on what
  lint rules are enabled.

- Mark `Required` and `required` as `@Deprecated`.
- Update SDK constraints to `^3.5.0`.

## 1.16.0

- Add `TargetKind`s to a few annotations to match custom-wired behavior that the
  Dart analyzer has been providing:

  - Require that `@factory` is only used on methods.
  - Require that `@Immutable` is only used on classes, extensions, and mixins.
  - Require that `@mustBeOverridden` and `@mustCallSuper` are only used on
    overridable members.
  - Require that `@sealed` is only used on classes.

- Updated `@doNotSubmit` to (1) disallow same-library access (unlike other
  visibility annotation), (2) allow parameters marked with `@doNotSubmit` to be
  used in nested functions, and (3) disallowed `@doNotSubmit` on required
  parameters:

  ```dart
  import 'package:meta/meta.dart';

  @doNotSubmit
  void a() {}

  void b() {
    // HINT: invalid_use_of_do_not_submit: ...
    a();
  }
  ```

  ```dart
  import 'package:meta/meta.dart';

  void test({
    @doNotSubmit bool solo = false
  }) {
    void nested() {
      // OK
      if (solo) { /*...*/ }
    }
  }
  ```

  ```dart
  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.parameter` is now allowed on a _representation type_, such as:

  ```dart
  // Ok, because `int _actual` is similar to a parameter declaration.
  extension type const FancyInt(@mustBeConst int _actual) {}
  ```

- Renamed `@ResourceIdentifier` to `@RecordUse`.

## 1.15.0

- Updated `@mustBeOverridden` to only flag missing overrides in concrete
  classes; in other words, abstract classes (including implicitly abstract, i.e
  `sealed`) and mixin declarations are _no longer required_ to provide an
  implementation:

  ```dart
  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 `@doNotSubmit` to (1) disallow same-library access (unlike other
  visibility annotation), (2) allow parameters marked with `@doNotSubmit` to be
  used in nested functions, and (3) disallowed `@doNotSubmit` on required
  parameters:

  ```dart
  import 'package:meta/meta.dart';

  @doNotSubmit
  void a() {}

  void b() {
    // HINT: invalid_use_of_do_not_submit: ...
    a();
  }
  ```

  ```dart
  import 'package:meta/meta.dart';

  void test({
    @doNotSubmit bool solo = false
  }) {
    void nested() {
      // OK
      if (solo) { /*...*/ }
    }
  }
  ```

  ```dart
  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 `@doNotSubmit` to 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`'s `solo: ...` parameter, which skips all other
  tests in a test suite when set to `true`. This parameter is useful during
  development, but should be prevented from being submitted:

  ```dart
  import 'package:meta/meta.dart';

  void test(
    String name,
    void Function() body, {
    @doNotSubmit bool solo = false
  }) {
    // ...
  }
  ```

  ```dart
  import 'package:test/test.dart';

  void main() {
    test(
      'my test', () {
        // ...
      },
      // HINT: invalid_use_of_do_not_submit: ...
      solo: true,
    );
  }
  ```

- Introduce `@mustBeConst` to annotate parameters which only accept constant
  arguments.

## 1.13.0

- Add type checks for the `@ResourceIdentifier` experimental annotation.

## 1.12.0

- Introduce the `@ResourceIdentifier` experimental annotation for static methods
  whose constant literal arguments should be collected during compilation.
- Indicate that `@required` and `@Required` are set to be deprecated for later
  removal.

## 1.11.0

- Introduce `TargetKind.extensionType` to indicate that an annotation is valid
  on any extension type declaration.

## 1.10.0

- Introduce `@redeclare` to annotate extension type members that redeclare
  members from a superinterface.
- Migrate the `TargetKind` enum to a class to ease the addition of new kinds.

## 1.9.1

- Update SDK constraints to `>=2.12.0 <4.0.0`.
- Mark `@reopen` stable.

## 1.9.0

- Introduce `@reopen` to annotate class or mixin declarations that can safely
  extend classes marked `base`, `final` or `interface`.
- Introduce `@MustBeOverridden` to 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 `noInline` and `tryInline` from `dart2js.dart` has been
  changed. This should not affect the use of these annotations in practice.

## 1.7.0

- Restore `TargetKindExtension` and `get displayString`.
  We published `analyzer 1.7.2` that is compatible with `TargetKindExtension`.

## 2.0.0 - removed

- Restore `TargetKindExtension` and `get 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 on
  `TargetKind`, and also declare `get displayString`. This causes a conflict.

## 1.5.0

- Add `TargetKindExtension.displayString`.

## 1.4.0

- Introduce `TargetKind.topLevelVariable` that indicates that an annotation
  is valid on any top-level variable declaration.
- Introduce `@useResult` to 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 <3.0.0` based on beta release
  guidelines.

## 1.3.0-nullsafety.5

- Allow prerelease versions of the `2.12` SDK.

## 1.3.0-nullsafety.4

- Introduce `@internal` to 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 `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 `unawaited` to mark invocations that return a `Future` where it's
  intentional that the future is not being awaited. (Moved from
  `package:pedantic`.)
- 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.

## 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](https://github.com/dart-lang/sdk/issues/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](https://github.com/dart-lang/sdk/issues/17999)). This
  is first available in Dart SDK 1.25.0-dev.1.0.

  ```dart
  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 `@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](https://github.com/dart-lang/sdk/issues/27384)).

  ```dart
  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](https://github.com/dart-lang/sdk/issues/25578)).

  ```dart
  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.