Manual Clock
This package is for testing current time and Timer related code.
The ManualClock class is a derived class of Clock.
With clock and fake_async libraries, you can test current time related code by using clock.now(). But inside fake async callback, you can't use await. Because of this restriction, Sometimes it is hard to test your code. With this library, you can test current time and Timer related code using await.
Restrictions
- Periodic timers of 0 duration are not supported.
- One-shot timers of 0 duration are supported.
- If a target code contains a code like
await Future.delayed(...), it will stop there permanently.
Getting started
pubspec.yaml
dev_dependencies:
manual_clock: ^latest_version
Usage
test('a test case', () async {
await withManualClock((clock) async {
final obj = ClassDependOnNow(...);
clock.elapse(Duration(...));
// You can use await inside callback
final result = await obj.getResult();
expect(result, ...);
// You can test Timers
var fired = false;
Timer(duration, () { fired = true; });
clock.elapse(duration);
expect(fired, true);
// If you need to wait for real life time inside callback,
// use waitRealLifeTime(duration)
await waitRealLifeTime(Duration(seconds: 10));
},
// optionally set initial time
initialTime: DateTime(2000, 1, 1));
});