Handle response error when body contains no valid json

client.go

@@ -209,12 +209,19 @@ func (c *Client) fullURL(suffix string, args ...any) string {
 }
 
 func (c *Client) handleErrorResp(resp *http.Response) error {
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return &RequestError{
+			HTTPStatusCode: resp.StatusCode,
+			Err:            fmt.Errorf("read resp body failed: %w", err),
+		}
+	}
 	var errRes ErrorResponse
-	err := json.NewDecoder(resp.Body).Decode(&errRes)
+	err = json.Unmarshal(data, &errRes)
 	if err != nil || errRes.Error == nil {
 		reqErr := &RequestError{
 			HTTPStatusCode: resp.StatusCode,
-			Err:            err,
+			Err:            fmt.Errorf("resp is not valid json: %s", string(data)),
 		}
 		if errRes.Error != nil {
 			reqErr.Err = errRes.Error

client_test.go

@@ -158,6 +158,18 @@ func TestHandleErrorResp(t *testing.T) {
 				}`)),
 			expected: "error, status code: 503, message: ",
 		},
+		{
+			name:     "500 invalid json",
+			httpCode: http.StatusInternalServerError,
+			body:     bytes.NewReader([]byte(`dummy`)),
+			expected: "error, status code: 500, message: resp is not valid json: dummy",
+		},
+		{
+			name:     "500 error body",
+			httpCode: http.StatusInternalServerError,
+			body:     &errorReader{err: errors.New("dummy")},
+			expected: "error, status code: 500, message: read resp body failed: dummy",
+		},
 	}
 
 	for _, tc := range testCases {
@@ -171,12 +183,6 @@ func TestHandleErrorResp(t *testing.T) {
 				t.Errorf("Unexpected error: %v , expected: %s", err, tc.expected)
 				t.Fail()
 			}
-
-			e := &APIError{}
-			if !errors.As(err, &e) {
-				t.Errorf("(%s) Expected error to be of type APIError", tc.name)
-				t.Fail()
-			}
 		})
 	}
 }