Flutter/Dart wait for a few seconds in unit testing

user_4323908 0
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I am writing a timer app. In unit testing how do I wait for few seconds to test if my timer is working properly?

// I want something like this.
test("Testing timer", () {
    int startTime = timer.seconds;
    timer.start();

    // do something to wait for 2 seconds

    expect(timer.seconds, startTime - 2);

});
dart flutter wait unit-testing
1 Answers

You can use awaitFuture.delayed(...)`:

test("Testing timer", () async {
    int startTime = timer.seconds;
    timer.start();

    // do something to wait for 2 seconds
    await Future.delayed(const Duration(seconds: 2), (){});

    expect(timer.seconds, startTime - 2);

});

An alternative would be fake_async with https://pub.dartlang.org/packages/clock to be able to freely manipulate the time used in the test.

user_2174080
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