fix timeout bug

Fixed a problem related to timeout config: ctx was being overwritten
when the timeout config value was set. As a result, the next retry
would immediately timeout. Fixed to not overwrite ctx when timeout
config value was set.

async_retry.go

@@ -94,9 +94,9 @@ func (a *asyncRetry) call(ctx context.Context, f RetryableFunc, config *Config)
 	return retry.Do(
 		func() error {
 			if config.timeout > 0 {
-				var timeoutCancel context.CancelFunc
-				ctx, timeoutCancel = context.WithTimeout(ctx, config.timeout)
+				timeoutCtx, timeoutCancel := context.WithTimeout(ctx, config.timeout)
 				defer timeoutCancel()
+				return f(timeoutCtx)
 			}
 			return f(ctx)
 		},

async_retry_test.go

@@ -124,9 +124,16 @@ func Test_asyncRetry_Do(t *testing.T) {
 			name: "Timeout set correctly for each try",
 			args: args{
 				f: func(ctx context.Context) error {
+					started := time.Now()
 					counter++
 					select {
 					case <-ctx.Done():
+						// Since the timeout for this test case is 10 msec,
+						// even considering the error of the measurement,
+						// at least 9 msec should have elapsed by the time `ctx.Done()` is received.
+						if time.Since(started) < (9 * time.Millisecond) {
+							return Unrecoverable(fmt.Errorf("timeout is too fast"))
+						}
 						if counter < 3 {
 							return fmt.Errorf("timeout")
 						}