Repository: uber-go/zap
File: clock_test.go (Go)

Code before:
	return &time.Ticker{}
}

func TestWithClock(t *testing.T) {
	date := time.Date(2077, 1, 23, 10, 15, 13, 441, time.UTC)
	clock := constantClock(date)
	withLogger(t, DebugLevel, []Option{WithClock(clock)}, func(log *Logger, logs *observer.ObservedLogs) {
		log.Info("")
		require.Equal(t, 1, logs.Len(), "Expected only one log entry to be written.")
		assert.Equal(t, date, logs.All()[0].Entry.Time, "Unexpected entry time.")
	})
}

func TestSystemClockNewTicker(t *testing.T) {
	var target = int32(3)
	var n atomic.Int32
	done := make(chan struct{})
	defer func() {
		<-done
		assert.Equal(t, target, n.Load())
	}() // wait for end

	quit := make(chan struct{})
	// Create a channel to increment every millisecond.
	go func(ticker *time.Ticker) {
		defer close(done)
		for {
			select {
			case <-quit:
				return
			case <-ticker.C:
				n.Inc()
				if n.Load() == target {
					ticker.Stop()
					close(quit)
				}
			}
		}
	}(_systemClock.NewTicker(time.Millisecond))
}


Review comment (refactor):
Do we need this to be a separate goroutine?
For this one, since we're blocking until three ticks, we can just do this all inline. It would simplify book keeping and it doesn't need to be an atomic because there would be no concurrency:

```
target := 3
var n int

ticker := _systemClock.NewTicker(..)
for range ticker.C {
  n++
  if n == target {
    ticker.Stop()
    return
  }
}
```

(We don't need the `assert.Equal` either because if the logic is faulty, the function will just loop forever.)

Code after:
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package zap

import (
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap/zaptest/observer"
)

type constantClock time.Time

func (c constantClock) Now() time.Time { return time.Time(c) }
func (c constantClock) NewTicker(d time.Duration) *time.Ticker {
	return &time.Ticker{}
}

func TestWithClock(t *testing.T) {
	date := time.Date(2077, 1, 23, 10, 15, 13, 441, time.UTC)
	clock := constantClock(date)
	withLogger(t, DebugLevel, []Option{WithClock(clock)}, func(log *Logger, logs *observer.ObservedLogs) {
		log.Info("")
		require.Equal(t, 1, logs.Len(), "Expected only one log entry to be written.")
		assert.Equal(t, date, logs.All()[0].Entry.Time, "Unexpected entry time.")
	})
}

func TestSystemClockNewTicker(t *testing.T) {
	want := 3

	var n int
	timer := _systemClock.NewTicker(time.Millisecond)
	for range timer.C {
		n++
		if n == want {
			return
		}
	}
}