Add unit test of retry support

mocks_test.go

@@ -14,9 +14,15 @@ type mockClient struct {
 	req  *http.Request
 	resp http.Response
 	err  error
+	cb   func(req *http.Request) // callback in .Do
 }
 
 func (c *mockClient) Do(req *http.Request) (*http.Response, error) {
+	defer func() {
+		if c.cb != nil {
+			c.cb(req)
+		}
+	}()
 	c.req = req
 	if c.err == nil {
 		c.resp.Header = c.req.Header
@@ -258,3 +264,20 @@ func (wc *mockWebsocketConn) SetWriteDeadline(t time.Time) error {
 func (wc *mockWebsocketConn) Subprotocol() string {
 	return wc.subprotocol
 }
+
+type mockNetError struct {
+	isTimeout   bool
+	isTemporary bool
+}
+
+func (e *mockNetError) Error() string {
+	return "mock net error"
+}
+
+func (e *mockNetError) Timeout() bool {
+	return e.isTimeout
+}
+
+func (e *mockNetError) Temporary() bool {
+	return e.isTemporary
+}

request.go

@@ -38,6 +38,7 @@ type Request struct {
 	maxRetries    int
 	minRetryDelay time.Duration
 	maxRetryDelay time.Duration
+	sleepFn       func(d time.Duration)
 
 	timeout time.Duration
 
@@ -122,6 +123,7 @@ func newRequest(
 		maxRetries:    0,
 		minRetryDelay: time.Millisecond * 50,
 		maxRetryDelay: time.Second * 5,
+		sleepFn:       time.Sleep,
 	}
 
 	r.initPath(path, pathargs...)
@@ -1920,7 +1922,7 @@ func (r *Request) retryRequest(reqFunc func() (*http.Response, error)) (
 			resp.Body.Close()
 		}
 
-		time.Sleep(delay)
+		r.sleepFn(delay)
 
 		delay *= 2
 		if delay > r.maxRetryDelay {