microsoft / clock Goto Github PK

:clock4: Time utility with lovely mocking support

License: MIT License

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clock's Introduction

clock

Time utility with lovely mocking support.

This is essentially a replacement for the time package which allows you to seamlessly swap in mock times, timers, and tickers. See the godocs (link above) for more detailed usage.

Example

hello.go

package main

import (
    "fmt"
    "github.com/mixer/clock"
)

func main() {
    fmt.Printf("the time is %s", displayer{clock.C}.formatted())
}

type displayer struct {
    c clock.Clock
}

func (d displayer) formatted() string {
    now := d.c.Now()
    return fmt.Sprintf("%d:%d:%d", now.Hour(), now.Minute(), now.Second())
}

hello_test.go

package main

import (
    "testing"
    "time"

    "github.com/mixer/clock"
    "github.com/stretchr/testify/assert"
)

func TestDisplaysCorrectly(t *testing.T) {
    date, _ := time.Parse(time.UnixDate, "Sat Mar  7 11:12:39 PST 2015")
    c := clock.NewMockClock(date)
    d := displayer{c}

    assert.Equal(t, "11:12:39", d.formatted())
    c.AddTime(42 * time.Second)
    assert.Equal(t, "11:13:21", d.formatted())
}

API & Compatibility

The API provided by this package and the mock version is nearly identical to that of the time package, with two notable differences:

The channel for Ticker and Timer instances is accessed via the .Chan() method, rather than reading the .C property. This allows the structures to be swapped out for their mock variants.
The mock Ticker never skips ticks when time advances. This allows you to call .AddTime/.SetTime on the mock clock without having to advance to each "ticked" time.

clock's People

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vikstrous pborzenkov zwass runeaune jacobmbr nicktitle joseustra kandros asdlei99 tooolbox classicvalues mdelah test-mass-forker-org-1 sliide ibazhitov linuxsuren poa00

clock's Issues

Ticker chan sometimes doesn't fire

I have this test:

func TestMockClock(t *testing.T) {
	clk := clock.NewMockClock()
	ticker := clk.NewTicker(250 * time.Millisecond)
	clk.AddTime(251 * time.Millisecond)
	select {
	case <-ticker.Chan():
		return
	case <-time.After(time.Second):
		t.Fatal("Timed out waiting for test to complete")
	}
}

If I run this test a bunch of times, it fails:

$ go test . -run TestMockClock -count 100000 -failfast
[... a bunch of successful runs ...]
--- FAIL: TestMockClock (1.00s)
	pinger_test.go:40: Timed out waiting for test to complete
FAIL
FAIL	github.com/symbiont-io/assembly/smartlog/lib/network	1.169s

Is there something wrong with my test setup?

Deadlock when ticker stopped with no readers on channel

The following test consistently causes a deadlock:

func TestTickerDeadlock(t *testing.T) {
	c := NewMockClock()
	tk := c.NewTicker(5 * time.Millisecond)
	c.AddTime(6 * time.Millisecond)
	time.Sleep(1 * time.Millisecond)
	tk.Stop()
}

Per the time godoc, the ticker may "drops tick to make up for slow receivers". We probably need to do this to avoid the deadlock here.

incorrect time returned on Ticker channel

test:

package main

import (
	"fmt"
	"time"

	"github.com/WatchBeam/clock"
)

func main() {
	date, _ := time.Parse(time.UnixDate, "0")
	c := clock.NewMockClock(date)
	ticker := c.NewTicker(time.Second)
	ch := ticker.Chan()
	done := make(chan struct{})
	go func() {
		chTime := <-ch
		cTime := c.Now()
		fmt.Println(chTime)
		fmt.Println(cTime)
		close(done)
	}()
	c.AddTime(time.Second)
	<-done
}

expected:

0001-01-01 00:00:01 +0000 UTC
0001-01-01 00:00:01 +0000 UTC

actual:

2016-12-06 11:19:51.326261153 +0000 UTC
0001-01-01 00:00:01 +0000 UTC

This repo is missing important files

There are important files that Microsoft projects should all have that are not present in this repository. A pull request has been opened to add the missing file(s). When the pr is merged this issue will be closed automatically.

Microsoft teams can learn more about this effort and share feedback within the open source guidance available internally.

Merge this pull request

Readme.md import bug

readme.md import bug

ticker doesn't close the channel after calling Stop()

Repro:

package main

import (
    "sync"
    "time"

    "github.com/WatchBeam/clock"
)

func main() {
    c := clock.NewMockClock(time.Now())
    ticker := c.NewTicker(time.Second)
    ch := ticker.Chan()
    wg := sync.WaitGroup{}
    wg.Add(1)
    go func() {
        for range ch {
        }
        wg.Done()
    }()
    ticker.Stop()
    wg.Wait()
}

TestTimerResets flaps when run with race detector

Not always, but typically using -count 100 is sufficient to see a few failures:

$ go test -race -run TestTimerResets -count 100
--- FAIL: TestTimerResets (0.05s)
	mock_test.go:14: expected timer to get after reset when interval is up after restarted
--- FAIL: TestTimerResets (0.05s)
	mock_test.go:14: expected timer to get after reset when interval is up after restarted
--- FAIL: TestTimerResets (0.05s)
	mock_test.go:14: expected timer to get after reset when interval is up after restarted
FAIL
exit status 1
FAIL	github.com/mixer/clock	3.573s

microsoft / clock Goto Github PK

clock's Introduction

clock

Example

API & Compatibility

clock's People

Contributors

Stargazers

Watchers

Forkers

clock's Issues

Ticker chan sometimes doesn't fire

Deadlock when ticker stopped with no readers on channel

incorrect time returned on Ticker channel

This repo is missing important files

Readme.md import bug

ticker doesn't close the channel after calling Stop()

TestTimerResets flaps when run with race detector

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