[retry] support pointer Stop error

Change-Id: Ie2013aac9ea6950ff47642c6ee54345cf22f3adf

utils/retry/retry.go

@@ -83,6 +83,9 @@ func retry(opt options, f func() error, opts ...Option) (r Result) {
 		if _, ok := err.(Stop); ok {
 			break
 		}
+		if s, ok := err.(*Stop); ok && s != nil {
+			break
+		}
 		// attempts <= 0 means retry forever.
 		if opt.Attempts > 0 && r.Attempts >= opt.Attempts {
 			break
@@ -119,10 +122,14 @@ func retry(opt options, f func() error, opts ...Option) (r Result) {
 	if err != nil {
 		if s, ok := err.(Stop); ok {
 			// Return the original error for later checking.
+			// Stop error from caller don't count for circuit breaker.
 			merr.Append(s.Err)
 			opt.Hook(r.Attempts, s.Err)
-
+		} else if s, ok := err.(*Stop); ok && s != nil {
+			// Return the original error for later checking.
 			// Stop error from caller don't count for circuit breaker.
+			merr.Append(s.Err)
+			opt.Hook(r.Attempts, s.Err)
 		} else {
 			merr.Append(err)
 			opt.Hook(r.Attempts, err)

utils/retry/retry_test.go

@@ -46,6 +46,48 @@ func Test_Retry(t *testing.T) {
 	is.Equal(merrors[2].Error(), "error 1")
 }
 
+func Test_Stop(t *testing.T) {
+	is := assert.New(t)
+
+	t.Run("struct Stop", func(t *testing.T) {
+		fakeErrFunc := fakeErrors(1)
+		r := Retry(3, 100*time.Millisecond, func() error {
+			err := fakeErrFunc()
+			if err != nil {
+				return err
+			}
+			return Stop{Err: fmt.Errorf("stop")}
+		})
+		is.True(!r.Ok)
+		is.Equal(r.Attempts, 2)
+		merr, ok := r.Error.(*SizedError)
+		is.True(ok)
+		merrors := merr.Errors()
+		is.Equal(len(merrors), 2)
+		is.Equal(merrors[0].Error(), "stop")
+		is.Equal(merrors[1].Error(), "error 1")
+	})
+
+	t.Run("pointer of struct Stop", func(t *testing.T) {
+		fakeErrFunc := fakeErrors(1)
+		r := Retry(3, 100*time.Millisecond, func() error {
+			err := fakeErrFunc()
+			if err != nil {
+				return err
+			}
+			return &Stop{Err: fmt.Errorf("stop")}
+		})
+		is.True(!r.Ok)
+		is.Equal(r.Attempts, 2)
+		merr, ok := r.Error.(*SizedError)
+		is.True(ok)
+		merrors := merr.Errors()
+		is.Equal(len(merrors), 2)
+		is.Equal(merrors[0].Error(), "stop")
+		is.Equal(merrors[1].Error(), "error 1")
+	})
+}
+
 func Test_Hook(t *testing.T) {
 	is := assert.New(t)
 	target := fakeErrors(3)