refs/tags/1.1.0-nullsafety.1 - clock

commit	e2018d8eeecc26f6b014a2f73491e64da53703cc	[log] [tgz]
author	Nate Bosch <nbosch1@gmail.com>	Tue Sep 22 09:57:46 2020 -0700
committer	GitHub <noreply@github.com>	Tue Sep 22 09:57:46 2020 -0700
tree	af2c967f2a8b6d7df43596b0560730066f6f80f4
parent	737be9ac12b5f01c1f55f95c9fe6e136bfe43e13 [diff]

tree: af2c967f2a8b6d7df43596b0560730066f6f80f4

README.md

This package provides a Clock class which encapsulates the notion of the “current time” and provides easy access to points relative to the current time. Different Clocks can have a different notion of the current time, and the default top-level clock's notion can be swapped out to reliably test timing-dependent code.

For example, you can use clock in your libraries like this:

// run_with_timing.dart
import 'package:clock/clock.dart';

/// Runs [callback] and prints how long it took.
T runWithTiming<T>(T Function() callback) {
  var stopwatch = clock.stopwatch()..start();
  var result = callback();
  print('It took ${stopwatch.elapsed}!');
  return result;
}

...and then test your code using the fake_async package, which automatically overrides the current clock:

// run_with_timing_test.dart
import 'run_with_timing.dart';

import 'package:fake_async/fake_async.dart';
import 'package:test/test.dart';

void main() {
  test('runWithTiming() prints the elapsed time', () {
    FakeAsync().run((async) {
      expect(() {
        runWithTiming(() {
          async.elapse(Duration(seconds: 10));
        });
      }, prints('It took 0:00:10.000000!'));
    });
  });
}