Testing

Making your test a KoinComponent with KoinTest

By import koin_test.dart, you will be able to use all available test methods:

  • inject() & get() - function to retrieve yoru instances from Koin

  • testModules(),testModule() & testKoinDeclaration() - help you check your configuration. These are functions marked as isTest, that is, they are equivalent to test();

  • declareModule() - to declare a module to be loaded in the global context of koin

  • declare() - to a instance to be loaded in the global context of koin

  • koinTearDown() - Register a tearDown function that close Koin afters tests, will be called after each test is run.

  • koinSetUp() - Register a setUp function that starts koin before tests, will be called after each test is run.

  • koinTest() - Configures the testing environment to automatically start and close Koin for each test.

class ComponentA {}
class ComponentB {
final ComponentA a;
ComponentB(this.a);
}
void main() {
test('should inject my components', () {
startKoin((app) {
app.module(module()
..single((s) => ComponentA())
..single((s) => ComponentB(s.get())));
});
// Lazy inject property
var componentA = inject<ComponentA>();
// directly request an instance
var componentB = get<ComponentB>();
expect(componentA, isNotNull);
expect(componentB.a, componentA);
});
}
TIP

Don't hesitate to overload Koin modules configuration to help you partly build your app.

Test SetUp

Create a Koin context for your test

You can easily create and hold a Koin context for each of your test with the following setup:

setUp((){
startKoin((app) {
app.module(myModule);
});
note

koin_test package does not have mockito as a dependency.

Mocking out of the box

Instead of making a new module each time you need a mock, you can declare a mock on the fly with declare:

class ComponentA {}
class ComponentB {
final ComponentA a;
ComponentB(this.a);
}
class ComponentAMock implements ComponentA {}
void main() {
setUp(() {
startKoin((app) {
app.module(Module()
..single((s) => ComponentA())
..single((s) => ComponentB(s.get())));
});
});
tearDown((){
stopKoin();
});
test('should inject my components', () {
var componentAMock = ComponentAMock();
// declare a mock instance to ComponentA.
declare<ComponentA>(componentAMock);
// retrieve mock, same as variable above
expect(get<ComponentA>(), isNotNull);
// retrieve mock, same as variable above
expect(get<ComponentA>(), isA<ComponentAMock>());
// is built with mocked ComponentA
expect(get<ComponentB>(), isNotNull);
// shoud get the same instance declared above
expect(get<ComponentA>(), componentAMock);
});
}

Checking your Koin modules

Koin offers a way to test if you Koin modules are good: testModules - walk through your definition tree and check if each definition is bound

void main(){
testModules('moduleChecktest - shoud be a valid module',[myModule1,myModule2]);
}

Starting & stopping Koin for your tests

Take attention to stop your koin instance (if you use startKoin in your tests) between every test. Else be sure to use koinApplication, for local koin instances or stopKoin() to stop the current global instance.

Edit this page