return response body as byte slice for RequestError type (sashabaranov#873)

Author: AyushSawant18588

client.go

@@ -285,20 +285,21 @@ func (c *Client) baseURLWithAzureDeployment(baseURL, suffix, model string) (newB
 }
 
 func (c *Client) handleErrorResp(resp *http.Response) error {
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("error, reading response body: %w", err)
+	}
 	if !strings.HasPrefix(resp.Header.Get("Content-Type"), "application/json") {
-		body, err := io.ReadAll(resp.Body)
-		if err != nil {
-			return fmt.Errorf("error, reading response body: %w", err)
-		}
 		return fmt.Errorf("error, status code: %d, status: %s, body: %s", resp.StatusCode, resp.Status, body)
 	}
 	var errRes ErrorResponse
-	err := json.NewDecoder(resp.Body).Decode(&errRes)
+	err = json.Unmarshal(body, &errRes)
 	if err != nil || errRes.Error == nil {
 		reqErr := &RequestError{
 			HTTPStatus:     resp.Status,
 			HTTPStatusCode: resp.StatusCode,
 			Err:            err,
+			Body:           body,
 		}
 		if errRes.Error != nil {
 			reqErr.Err = errRes.Error

error.go

@@ -29,6 +29,7 @@ type RequestError struct {
 	HTTPStatus     string
 	HTTPStatusCode int
 	Err            error
+	Body           []byte
 }
 
 type ErrorResponse struct {