clock

NOTE: This README has not yet been updated to reflect the fixes/changes. Please refer to the source code in the meantime.

Clock is a small library for mocking time in Go. It provides an interface around the standard library's time package so that the application can use the realtime clock while tests can use the mock clock.

Usage

Realtime Clock

Your application can maintain a Clock variable that will allow realtime and mock clocks to be interchangable. For example, if you had an Application type:

import "github.com/aristanetworks/clock"

type Application struct {
	Clock clock.Clock
}

You could initialize it to use the realtime clock like this:

var app Application
app.Clock = clock.New()
...

Then all timers and time-related functionality should be performed from the Clock variable.

Mocking time

In your tests, you will want to use a Mock clock:

import (
	"testing"

	"github.com/aristanetworks/clock/mock"
)

func TestApplication_DoSomething(t *testing.T) {
	mock := mock.NewMockClock(ctrl)
	app := Application{Clock: mock}
	...
}

Now that you've initialized your application to use the mock clock, you can use the standard gomock methods to mock any call for any method.

Examples

fake Sleep

mock := clock.NewMockClock(ctrl)

mock.EXPECT().Sleep(gomock.Any()).AnyTimes()

Return a fake time

mock := clock.NewMockClock(ctrl)

now := time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
mock.EXPECT().Now().Return(now).AnyTimes()