From 2735b134c25f28ca0e7ed83661260652acd907e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gergely=20Nov=C3=A1k?= <novak.r.gergely@gmail.com>
Date: Wed, 15 Feb 2023 16:27:58 +0100
Subject: [PATCH] Retry on internal server errors (#242)

---
 marketdata/rest.go      |  8 ++++++--
 marketdata/rest_test.go | 11 +++++++----
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/marketdata/rest.go b/marketdata/rest.go
index 76a5aad..2d6aacf 100644
--- a/marketdata/rest.go
+++ b/marketdata/rest.go
@@ -97,13 +97,17 @@ func defaultDo(c *Client, req *http.Request) (*http.Response, error) {
 
 	var resp *http.Response
 	var err error
+
+RetryLoop:
 	for i := 0; ; i++ {
 		resp, err = c.httpClient.Do(req)
 		if err != nil {
 			return nil, err
 		}
-		if resp.StatusCode != http.StatusTooManyRequests {
-			break
+		switch resp.StatusCode {
+		case http.StatusTooManyRequests, http.StatusInternalServerError:
+		default:
+			break RetryLoop
 		}
 		if i >= c.opts.RetryLimit {
 			break
diff --git a/marketdata/rest_test.go b/marketdata/rest_test.go
index 7067c25..37d03f3 100644
--- a/marketdata/rest_test.go
+++ b/marketdata/rest_test.go
@@ -38,7 +38,8 @@ func TestDefaultDo_InternalServerError(t *testing.T) {
 	defer func() { os.Setenv("APCA_API_DATA_URL", originalDataURL) }()
 	require.NoError(t, os.Setenv("APCA_API_DATA_URL", server.URL))
 	client := NewClient(ClientOpts{
-		OAuth: "myoauthkey",
+		OAuth:      "myoauthkey",
+		RetryDelay: time.Nanosecond,
 	})
 	_, err := client.GetLatestBar("SPY", GetLatestBarRequest{})
 	require.Error(t, err)
@@ -49,8 +50,10 @@ func TestDefaultDo_Retry(t *testing.T) {
 	tryCount := 0
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch tryCount {
-		case 0:
+		case 0, 2:
 			http.Error(w, "too many requests", http.StatusTooManyRequests)
+		case 1:
+			http.Error(w, "internal server error occurred", http.StatusInternalServerError)
 		default:
 			fmt.Fprint(w, `{"bars":{"SPY":{"t":"2021-11-20T00:59:00Z","o":469.18,"h":469.18,"l":469.11,"c":469.17,"v":740,"n":11,"vw":469.1355}}}`)
 		}
@@ -59,8 +62,8 @@ func TestDefaultDo_Retry(t *testing.T) {
 	defer server.Close()
 	client := NewClient(ClientOpts{
 		BaseURL:    server.URL,
-		RetryDelay: time.Millisecond,
-		RetryLimit: 1,
+		RetryDelay: time.Nanosecond,
+		RetryLimit: 5,
 	})
 	bar, err := client.GetLatestBar("SPY", GetLatestBarRequest{})
 	require.NoError(t, err)