github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/util/timeutil/stopwatch_test.go (about)

     1  // Copyright 2019 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package timeutil
    12  
    13  import (
    14  	"testing"
    15  	"time"
    16  
    17  	"github.com/stretchr/testify/require"
    18  )
    19  
    20  // TestStopWatchStart makes sure that consequent calls to Start do not reset
    21  // the internal startedAt time.
    22  func TestStopWatchStart(t *testing.T) {
    23  	timeSource := NewTestTimeSource()
    24  	w := newStopWatch(timeSource.Now)
    25  
    26  	w.Start()
    27  	timeSource.Advance()
    28  	w.Start()
    29  	timeSource.Advance()
    30  	w.Stop()
    31  
    32  	expected, actual := timeSource.Elapsed(), w.Elapsed()
    33  	require.Equal(t, expected, actual)
    34  }
    35  
    36  // TestStopWatchStop makes sure that only the first call to Stop changes the
    37  // state of the stop watch.
    38  func TestStopWatchStop(t *testing.T) {
    39  	timeSource := NewTestTimeSource()
    40  	w := newStopWatch(timeSource.Now)
    41  
    42  	w.Start()
    43  	timeSource.Advance()
    44  	w.Stop()
    45  
    46  	expected, actual := timeSource.Elapsed(), w.Elapsed()
    47  	require.Equal(t, expected, actual)
    48  
    49  	timeSource.Advance()
    50  	w.Stop()
    51  	require.Equal(t, actual, w.Elapsed(), "consequent call to StopWatch.Stop changed the elapsed time")
    52  }
    53  
    54  // TestStopWatchElapsed makes sure that the stop watch records the elapsed time
    55  // correctly.
    56  func TestStopWatchElapsed(t *testing.T) {
    57  	timeSource := NewTestTimeSource()
    58  	w := newStopWatch(timeSource.Now)
    59  	expected := time.Duration(10)
    60  
    61  	w.Start()
    62  	for i := int64(0); i < int64(expected); i++ {
    63  		timeSource.Advance()
    64  	}
    65  	w.Stop()
    66  
    67  	require.Equal(t, expected, w.Elapsed())
    68  }