feat(testutil): add unit tests and remove unused functions

- Added `pkg/util/testutil/testutil_test.go` for unit testing.
- Removed unused functions from `pkg/util/testutil/testutil.go`.

pkg/util/testutil/testutil.go

@@ -6,8 +6,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/pkg/errors"
-
 	"github.com/kakao/varlog/internal/vtesting"
 )
 
@@ -36,62 +34,6 @@ func CompareWaitN(factor int64, cmp func() bool) bool {
 	return CompareWait(cmp, vtesting.TimeoutUnitTimesFactor(factor))
 }
 
-func CompareWait100(cmp func() bool) bool {
-	return CompareWaitN(100, cmp)
-}
-
-func CompareWait10(cmp func() bool) bool {
-	return CompareWaitN(10, cmp)
-}
-
-func CompareWait1(cmp func() bool) bool {
-	return CompareWaitN(1, cmp)
-}
-
-func CompareWaitErrorWithRetryInterval(cmp func() (bool, error), timeout time.Duration, retryInterval time.Duration) error {
-	after := time.NewTimer(timeout)
-	defer after.Stop()
-
-	numTries := 0
-	for {
-		select {
-		case <-after.C:
-			return errors.Errorf("compare wait timeout (%s,tries=%d)", timeout.String(), numTries)
-		default:
-			numTries++
-			ok, err := cmp()
-			if err != nil {
-				return err
-			}
-
-			if ok {
-				return nil
-			}
-			time.Sleep(retryInterval)
-		}
-	}
-}
-
-func CompareWaitError(cmp func() (bool, error), timeout time.Duration) error {
-	return CompareWaitErrorWithRetryInterval(cmp, timeout, time.Millisecond)
-}
-
-func CompareWaitErrorWithRetryIntervalN(factor int64, retryInterval time.Duration, cmp func() (bool, error)) error {
-	if factor < 1 {
-		factor = 1
-	}
-
-	return CompareWaitErrorWithRetryInterval(cmp, vtesting.TimeoutUnitTimesFactor(factor), retryInterval)
-}
-
-func CompareWaitErrorN(factor int64, cmp func() (bool, error)) error {
-	if factor < 1 {
-		factor = 1
-	}
-
-	return CompareWaitError(cmp, vtesting.TimeoutUnitTimesFactor(factor))
-}
-
 func GetFunctionName(i interface{}) string {
 	a := runtime.FuncForPC(reflect.ValueOf(i).Pointer()).Name()
 	s := strings.Split(a, "/")

pkg/util/testutil/testutil_test.go

@@ -0,0 +1,62 @@
+package testutil_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/kakao/varlog/pkg/util/testutil"
+)
+
+func TestCompareWait(t *testing.T) {
+	tcs := []struct {
+		cmp  func() bool
+		want bool
+	}{
+		{cmp: func() bool { return true }, want: true},
+		{cmp: func() bool { return false }, want: false},
+	}
+
+	for _, tc := range tcs {
+		got := testutil.CompareWait(tc.cmp, time.Second)
+		require.Equal(t, tc.want, got)
+	}
+}
+
+func TestCompareWaitN_Factor0(t *testing.T) {
+	ts := time.Now()
+	testutil.CompareWaitN(0, func() bool {
+		return false
+	})
+	factor0 := time.Since(ts)
+
+	ts = time.Now()
+	testutil.CompareWaitN(1, func() bool {
+		return false
+	})
+	factor1 := time.Since(ts)
+
+	require.InEpsilon(t, 1.0, factor1/factor0, float64((10 * time.Millisecond).Nanoseconds()))
+}
+
+func TestCompareWaitN_Factor2(t *testing.T) {
+	ts := time.Now()
+	testutil.CompareWaitN(1, func() bool {
+		return false
+	})
+	factor1 := time.Since(ts)
+
+	ts = time.Now()
+	testutil.CompareWaitN(2, func() bool {
+		return false
+	})
+	factor2 := time.Since(ts)
+
+	require.InEpsilon(t, 2.0, factor2/factor1, float64((10 * time.Millisecond).Nanoseconds()))
+}
+
+func TestGetFunctionName(t *testing.T) {
+	got := testutil.GetFunctionName(TestGetFunctionName)
+	require.Equal(t, "testutil_test.TestGetFunctionName", got)
+}