Move controlledClock to ztest.MockClock

We need to be able to use the controlled clock for some other tests so
move it from clock_test to the ztest package and rename it to MockClock.

To keep the interface for the MockClock clear,
don't embed the benbjohnson/clock and instead,
use it as an attribute.

internal/ztest/clock.go

@@ -0,0 +1,50 @@
+// Copyright (c) 2021 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 ztest
+
+import (
+	"time"
+
+	"github.com/benbjohnson/clock"
+)
+
+// MockClock provides control over the time.
+type MockClock struct{ m *clock.Mock }
+
+// NewMockClock builds a new mock clock that provides control of time.
+func NewMockClock() *MockClock {
+	return &MockClock{clock.NewMock()}
+}
+
+// Now reports the current time.
+func (c *MockClock) Now() time.Time {
+	return c.m.Now()
+}
+
+// NewTicker returns a time.Ticker that ticks at the specified frequency.
+func (c *MockClock) NewTicker(d time.Duration) *time.Ticker {
+	return &time.Ticker{C: c.m.Ticker(d).C}
+}
+
+// Add progresses time by the given duration.
+func (c *MockClock) Add(d time.Duration) {
+	c.m.Add(d)
+}

internal/ztest/clock_test.go

@@ -0,0 +1,57 @@
+// Copyright (c) 2021 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 ztest
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/atomic"
+)
+
+func TestMockClock_NewTicker(t *testing.T) {
+	var n atomic.Int32
+	clock := NewMockClock()
+
+	done := make(chan struct{})
+	defer func() { <-done }() // wait for end
+
+	quit := make(chan struct{})
+	// Create a channel to increment every microsecond.
+	go func(ticker *time.Ticker) {
+		defer close(done)
+		for {
+			select {
+			case <-quit:
+				ticker.Stop()
+				return
+			case <-ticker.C:
+				n.Inc()
+			}
+		}
+	}(clock.NewTicker(time.Microsecond))
+
+	// Move clock forward.
+	clock.Add(2 * time.Microsecond)
+	assert.Equal(t, int32(2), n.Load())
+	close(quit)
+}

zapcore/buffered_write_syncer_test.go

@@ -107,7 +107,7 @@ func TestBufferWriter(t *testing.T) {
 
 	t.Run("flush timer", func(t *testing.T) {
 		buf := &bytes.Buffer{}
-		clock := newControlledClock()
+		clock := ztest.NewMockClock()
 		ws := &BufferedWriteSyncer{
 			WS:            AddSync(buf),
 			Size:          6,

zapcore/clock.go

@@ -20,9 +20,7 @@
 
 package zapcore
 
-import (
-	"time"
-)
+import "time"
 
 // DefaultClock is the default clock used by Zap in operations that require
 // time. This clock uses the system clock for all operations.

zapcore/clock_test.go

@@ -24,49 +24,11 @@ import (
 	"testing"
 	"time"
 
-	"github.com/benbjohnson/clock"
-	"github.com/stretchr/testify/assert"
-	"go.uber.org/atomic"
+	"go.uber.org/zap/internal/ztest"
 )
 
-// controlledClock provides control over the time via a mock clock.
-type controlledClock struct{ *clock.Mock }
-
-func newControlledClock() *controlledClock {
-	return &controlledClock{clock.NewMock()}
-}
-
-func (c *controlledClock) NewTicker(d time.Duration) *time.Ticker {
-	return &time.Ticker{C: c.Ticker(d).C}
-}
-
-func TestControlledClock_NewTicker(t *testing.T) {
-	var n atomic.Int32
-	ctrlMock := newControlledClock()
-
-	done := make(chan struct{})
-	defer func() { <-done }() // wait for end
-
-	quit := make(chan struct{})
-	// Create a channel to increment every microsecond.
-	go func(ticker *time.Ticker) {
-		defer close(done)
-		for {
-			select {
-			case <-quit:
-				ticker.Stop()
-				return
-			case <-ticker.C:
-				n.Inc()
-			}
-		}
-	}(ctrlMock.NewTicker(time.Microsecond))
-
-	// Move clock forward.
-	ctrlMock.Add(2 * time.Microsecond)
-	assert.Equal(t, int32(2), n.Load())
-	close(quit)
-}
+// Verify that the mock clock satisfies the Clock interface.
+var _ Clock = (*ztest.MockClock)(nil)
 
 func TestSystemClock_NewTicker(t *testing.T) {
 	want := 3