refs/tags/1.1.0-nullsafety.2 - clock

commit	a494269254ba978e7ef8f192c5f7fec3fc05b9d3	[log] [tgz]
author	Jacob MacDonald <jakemac@google.com>	Fri Oct 23 13:26:04 2020 -0700
committer	GitHub <noreply@github.com>	Fri Oct 23 13:26:04 2020 -0700
tree	0cbd4f147f5c53a6f5dc9c789d25cf0096d43236
parent	e2018d8eeecc26f6b014a2f73491e64da53703cc [diff]

tree: 0cbd4f147f5c53a6f5dc9c789d25cf0096d43236

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!'));
    });
  });
}