• Fix generation of method with a parameter with a default value which includes a top-level function.
  • Migrate example code to null safety.
  • Breaking change: Change the error which is thrown if a method is called and no method stub was found, from NoSuchMethodError to MissingStubError.
  • Breaking change: Mock.noSuchMethod's optional positional parameter, “returnValue” is changed to a named parameter, and a second named parameter is added. Any manual mocks which call Mock.noSuchMethod with a second positional argument will need to instead use the named parameter.
  • Allow real calls to mock methods which return void (like setters) or Future<void>, even if unstubbed.


  • Fix noSuchMethod invocation of setters in generated mocks.


  • Annotate overridden getters and setters with @override.


  • Improve static analysis of generated code.
  • Make implicit casts from dynamic in getters explicit.


  • Fix issue with generated code which references a class declared in a part (#310).


  • Fix an issue with generated mocks overriding methods from Object, such as operator == (#306).
  • Fix an issue with relative imports in generated mocks.


  • Migrate the core libraries and tests to null safety. The builder at lib/src/builder.dart opts out of null safety.
  • Add http back to dev_dependencies. It's used by the example.
  • Remove deprecated typed, typedArgThat, and typedCaptureThat APIs.


  • Allow using analyzer 0.40.
  • throwOnMissingStub accepts an optional argument, exceptionBuilder, which will be called to build and throw a custom exception when a missing stub is called.


  • Introduce experimental code-generated mocks. This is primarily to support the new “Non-nullable by default” (NNBD) type system coming soon to Dart.
  • Add an optional second parameter to Mock.noSuchMethod. This may break clients who use the Mock class in unconventional ways, such as overriding noSuchMethod on a class which extends Mock. To fix, or prepare such code, add a second parameter to such overriding noSuchMethod declaration.
  • Increase minimum Dart SDK to 2.7.0.
  • Remove Fake class; export identical Fake class from the test_api package.


  • Mark the unexported and accidentally public setDefaultResponse as deprecated.
  • Mark the not useful, and not generally used, named function as deprecated.
  • Produce a meaningful error message if an argument matcher is used outside of stubbing (when) or verification (verify and untilCalled).


  • Add a Fake class for implementing a subset of a class API as overrides without misusing the Mock class.


  • Replace the dependency on the test package with a dependency on the new test_api package. This dramatically reduces mockito's transitive dependencies.

    This bump can result in runtime errors when coupled with a version of the test package older than 1.4.0.


  • Rollback the test_api part of the 3.0.1 release. This was breaking tests that use Flutter's current test tools, and will instead be released as part of Mockito 4.0.0.


  • Replace the dependency on the test package with a dependency on the new test_api package. This dramatically reduces mockito's transitive dependencies.
  • Internal improvements to tests and examples.


  • Deprecate the typed API; instead of wrapping other Mockito API calls, like any, argThat, captureAny, and captureArgThat, with a call to typed, the regular API calls are to be used by themselves. Passing any and captureAny as named arguments must be replaced with anyNamed() and captureAnyNamed, respectively. Passing argThat and captureThat as named arguments must include the named parameter.

  • Introduce a backward-and-forward compatible API to help users migrate to Mockito 3. See more details in the upgrading-to-mockito-3 doc.

  • thenReturn now throws an ArgumentError if either a Future or Stream is provided. thenReturn calls with futures and streams should be changed to thenAnswer. See the README for more information.

  • Support stubbing of void methods in Dart 2.

  • thenReturn and thenAnswer now support generics and infer the correct types from the when call.

  • Completely remove the mirrors implementation of Mockito (mirrors.dart).

  • Fix compatibility with new noSuchMethod Forwarding feature of Dart 2. This is thankfully a mostly backwards-compatible change. This means that this version of Mockito should continue to work:

    • with Dart >=2.0.0-dev.16.0,
    • with Dart 2 runtime semantics (i.e. with dart --preview-dart-2, or with Flutter Beta 3), and
    • with the new noSuchMethod Forwarding feature, when it lands in CFE, and when it lands in DDC.

    This change, when combined with noSuchMethod Forwarding, will break a few code paths which do not seem to be frequently used. Two examples:

    class A {
      int fn(int a, [int b]) => 7;
    class MockA extends Mock implements A {}
    var a = new MockA();
    when(a.fn(typed(any), typed(any))).thenReturn(0);

    This used to print null, because only one argument was passed, which did not match the two-argument stub. Now it will print 0, as the real call contains a value for both the required argument, and the optional argument.

    a.fn(2, 3);
    print(verify(a.fn(typed(captureAny), typed(captureAny))).captured);

    This used to print [2, 3], because only the second call matched the verify call. Now, it will print [1, null, 2, 3], as both real calls contain a value for both the required argument, and the optional argument.

  • Upgrade package dependencies.

  • Throw an exception when attempting to stub a method on a Mock object that already exists.


  • Add new feature to wait for an interaction: untilCalled. See the README for documentation.
  • capture* calls outside of a verify* call no longer capture arguments.
  • Some collections require stricter argument matching. For example, a stub like: mock.methodWithListArgs([1,2,3].map((e) => e*2)) (note the Iterable argument) will no longer match the following stub: when(mock.methodWithListArgs([42])).thenReturn(7);.


  • Add documentation for when, verify, verifyNever, resetMockitoState.
  • Expose throwOnMissingStub, resetMockitoState.
  • Improve failure message for verify.
  • SDK version ceiling bumped to <2.0.0-dev.infinity to support Dart 2.0 development testing.
  • Add a Mockito + test package example at test/example/iss.


  • Start using the new InvocationMatcher instead of the old matcher.
  • Change throwOnMissingStub back to invoking Object.noSuchMethod:
    • It was never documented what the thrown type should be expected as.
    • You can now just rely on throwsNoSuchMethodError if you want to catch it.


  • Add a new throwOnMissingStub method to the API.


  • Removed mockito_no_mirrors.dart


  • Remove export of spy and any dart:mirrors based API from mockito.dart. Users may import as package:mockito/mirrors.dart going forward.
  • Deprecated mockito_no_mirrors.dart; replace with mockito.dart.
  • Require Dart SDK >=1.21.0 <2.0.0 to use generic methods.


  • Add a new thenThrow method to the API.
  • Document thenAnswer in the README.
  • Add more dartdoc.


  • Add a new typed API that is compatible with Dart Dev Compiler; documented in README.md.


  • Move the reflection-based spy code into a private source file. Now package:mockito/mockito.dart includes this reflection-based API, and a new package:mockito/mockito_no_mirrors.dart doesn't require mirrors.


  • Equality matcher used by default to simplify matching collections as arguments. Should be non-breaking change in most cases, otherwise consider using argThat(identical(arg)).


  • Added support for spy.


  • Migrate from the unittest package to use the new test package.
  • Format code using dartformat