state_notifier_test 0.0.10

A testing library which makes it easy to test StateNotifier. Built to be used with the state_notifier, riverpod or flutter_riverpod packages.

Package

Package is a port of felangel's bloc_test, modified to work with StateNotifier class

Installation

Add to dev dependencies inside pubspec_yaml:

dev_dependencies:
  state_notifier_test: [version]

Usage

import 'package:state_notifier_test.dart';

stateNotifierTest(
  'CounterNotifier emits [9,10] when seeded with 9',
  build: () => CounterNotifier(),
  seed: () => [9],
  actions: (stateNotifier) => stateNotifier.increment(),
  expect: () => [9,10],
);

class CounterStateNotifier extends StateNotifier<int> {
  CounterStateNotifier() : super(0);

  void increment() {
    state = state + 1;
  }
}

stateNotifierTest can also be used to skip any number of emitted states before asserting against the expected states. skip defaults to 0.

stateNotifierTest(
  'CounterNotifier emits [2] when increment is called twice',
  build: () => CounterNotifier(),
  actions: (stateNotifier) {
    stateNotifier
      ..increment()
      ..increment();
  },
  skip: 1,
  expect: () => [2],
);

stateNotifierTest can also be used to verify internal stateNotifier functionality.

stateNotifierTest(
  'CounterNotifier emits [1] when increment is called',
  build: () => CounterNotifier(),
  actions: (stateNotifier) => stateNotifier.increment(),
  expect: () => [1],
  verify: (_) {
    verify(() => repository.someMethod(any())).called(1);
  }
);

Testing Options

setUp is optional and should be used to set up any dependencies prior to initializing the stateNotifier under test. setUp should be used to set up state necessary for a particular test case. For common set up code, prefer to use setUp from package:test/test.dart.

build should construct and return the stateNotifier under test.

seed is an optional Function that returns an Iterable of States which will be used to seed the stateNotifier before actions is called.

actions is an optional callback which will be invoked with the stateNotifier under test and should be used to interactions with the stateNotifier.

skip is an optional int which can be used to skip any number of states. skip defaults to 0.

expect is an optional Function that returns a Matcher which the stateNotifier under test is expected to emit after actions is executed.

verify is an optional callback which is invoked after expect and can be used for additional verification/assertions. verify is called with the stateNotifier returned by build.

errors is an optional Function that returns a Matcher which the stateNotifier under test is expected to throw after actions is executed.

tearDown is optional and can be used to execute any code after the test has run. tearDown should be used to clean up after a particular test case. For common tear down code, prefer to use tearDown from package:test/test.dart.

expectInitialState is an optional bool.If set to true, the initial state from the constructor will also be checked. Useful when you want to validate the initial state. Note: if set to true, it will only catch the last assigned state in the constructor. expectInitialState defaults to false.