remote-write: TestClientRetryAfter status code 500

and compare the retryAfter values.

Signed-off-by: William Dumont <william.dumont@grafana.com>

storage/remote/client_test.go

@@ -88,6 +88,7 @@ func TestClientRetryAfter(t *testing.T) {
 	setupServer := func(statusCode int) *httptest.Server {
 		return httptest.NewServer(
 			http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Set("Retry-After", "5")
 				http.Error(w, longErrMessage, statusCode)
 			}),
 		)
@@ -114,9 +115,11 @@ func TestClientRetryAfter(t *testing.T) {
 		statusCode          int
 		retryOnRateLimit    bool
 		expectedRecoverable bool
+		expectedRetryAfter  model.Duration
 	}{
-		{"TooManyRequests - No Retry", http.StatusTooManyRequests, false, false},
-		{"TooManyRequests - With Retry", http.StatusTooManyRequests, true, true},
+		{"TooManyRequests - No Retry", http.StatusTooManyRequests, false, false, 0},
+		{"TooManyRequests - With Retry", http.StatusTooManyRequests, true, true, 5 * model.Duration(time.Second)},
+		{"InternalServerError", http.StatusInternalServerError, false, true, 5 * model.Duration(time.Second)}, // HTTP 5xx errors do not depend on retryOnRateLimit.
 	}
 
 	for _, tc := range testCases {
@@ -132,6 +135,9 @@ func TestClientRetryAfter(t *testing.T) {
 			var recErr RecoverableError
 			err = c.Store(context.Background(), []byte{}, 0)
 			require.Equal(t, tc.expectedRecoverable, errors.As(err, &recErr), "Mismatch in expected recoverable error status.")
+			if tc.expectedRecoverable {
+				require.Equal(t, tc.expectedRetryAfter, err.(RecoverableError).retryAfter)
+			}
 		})
 	}
 }