README
¶
clock
Package clock provides an abstraction for system time that enables testing of time-sensitive code.
Where you'd use time.Now, instead use clk.Now where clk is an instance of
clock.Clock.
When running your code in production, pass it a Clock given by
clock.Default() and when you're running it in your tests, pass it an instance
of Clock from NewFake().
When you do that, you can use FakeClock's Add and Set methods to control
how time behaves in your tests. That makes the tests you'll write more reliable
while also expanding the space of problems you can test.
This code intentionally does not attempt to provide an abstraction over
time.Ticker and time.Timer because Go does not have the runtime or API hooks
available to do so reliably. See https://github.com/golang/go/issues/8869
As with any use of time, be sure to test Time equality with
time.Time#Equal, not ==.
For API documentation, see the godoc.
Documentation
¶
Overview ¶
Package clock provides an abstraction for system time that enables testing of time-sensitive code.
Where you'd use time.Now, instead use clk.Now where clk is an instance of Clock.
When running your code in production, pass it a Clock given by clock.Default() and when you're running it in your tests, pass it an instance of Clock from NewFake().
When you do that, you can use FakeClock's Add and Set methods to control how time behaves in your tests. That makes the tests you'll write more reliable while also expanding the space of problems you can test.
This code intentionally does not attempt to provide an abstraction over time.Ticker and time.Timer because Go does not have the runtime or API hooks available to do so reliably. See https://github.com/golang/go/issues/8869
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Clock ¶
type Clock interface {
// Now returns the Clock's current view of the time. Mutating the
// returned Time will not mutate the clock's time.
Now() time.Time
// Sleep causes the current goroutine to sleep for the given duration.
Sleep(time.Duration)
// After returns a channel that fires after the given duration.
After(time.Duration) <-chan time.Time
// Since is a short hand for Now().Sub(t).
Since(time.Time) time.Duration
// NewTimer makes a Timer based on this clock's time. Using Timers and
// negative durations in the Clock or Timer API is undefined behavior and
// may be changed.
NewTimer(time.Duration) *Timer
}
Clock is an abstraction over system time. New instances of it can be made with Default and NewFake.
Example ¶
c := New() now := c.Now() fmt.Println(now.UTC().Zone())
Output: UTC 0
type FakeClock ¶
type FakeClock interface {
Clock
// Adjust the time that will be returned by Now.
Add(d time.Duration)
// Set the Clock's time to exactly the time given.
Set(t time.Time)
}
FakeClock is a Clock with additional controls. The return value of Now return can be modified with Add. Use NewFake to get a thread-safe FakeClock implementation.
Example ¶
c := New()
fc := NewFake()
fc.Add(20 * time.Hour)
fc.Add(-5 * time.Minute) // negatives work, as well
if fc.Now().Equal(fc.Now()) {
fmt.Println("FakeClocks' Times always equal themselves.")
}
if !c.Now().Equal(fc.Now()) {
fmt.Println("Clock and FakeClock can be set to different times.")
}
if !fc.Now().Equal(NewFake().Now()) {
fmt.Println("FakeClocks work independently, too.")
}
Output: FakeClocks' Times always equal themselves. Clock and FakeClock can be set to different times. FakeClocks work independently, too.
Source Files