Merge pull request #1919 from vntw/ignore-head-req-body

Ignore response body during HEAD request error handling

gitlab.go

@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
@@ -65,6 +66,8 @@ const (
 	PrivateToken
 )
 
+var ErrNotFound = errors.New("404 Not Found")
+
 // A Client manages communication with the GitLab API.
 type Client struct {
 	// HTTP client used to communicate with the API.
@@ -504,7 +507,7 @@ func (c *Client) retryHTTPBackoff(min, max time.Duration, attemptNum int, resp *
 // min and max are mainly used for bounding the jitter that will be added to
 // the reset time retrieved from the headers. But if the final wait time is
 // less then min, min will be used instead.
-func rateLimitBackoff(min, max time.Duration, attemptNum int, resp *http.Response) time.Duration {
+func rateLimitBackoff(min, max time.Duration, _ int, resp *http.Response) time.Duration {
 	// rnd is used to generate pseudo-random numbers.
 	rnd := rand.New(rand.NewSource(time.Now().UnixNano()))
 
@@ -957,20 +960,28 @@ type ErrorResponse struct {
 
 func (e *ErrorResponse) Error() string {
 	path, _ := url.QueryUnescape(e.Response.Request.URL.Path)
-	u := fmt.Sprintf("%s://%s%s", e.Response.Request.URL.Scheme, e.Response.Request.URL.Host, path)
-	return fmt.Sprintf("%s %s: %d %s", e.Response.Request.Method, u, e.Response.StatusCode, e.Message)
+	url := fmt.Sprintf("%s://%s%s", e.Response.Request.URL.Scheme, e.Response.Request.URL.Host, path)
+
+	if e.Message == "" {
+		return fmt.Sprintf("%s %s: %d", e.Response.Request.Method, url, e.Response.StatusCode)
+	} else {
+		return fmt.Sprintf("%s %s: %d %s", e.Response.Request.Method, url, e.Response.StatusCode, e.Message)
+	}
 }
 
 // CheckResponse checks the API response for errors, and returns them if present.
 func CheckResponse(r *http.Response) error {
 	switch r.StatusCode {
 	case 200, 201, 202, 204, 304:
 		return nil
+	case 404:
+		return ErrNotFound
 	}
 
 	errorResponse := &ErrorResponse{Response: r}
+
 	data, err := io.ReadAll(r.Body)
-	if err == nil && data != nil {
+	if err == nil && strings.TrimSpace(string(data)) != "" {
 		errorResponse.Body = data
 
 		var raw interface{}

gitlab_test.go

@@ -203,6 +203,35 @@ func TestCheckResponseOnUnknownErrorFormat(t *testing.T) {
 	}
 }
 
+func TestCheckResponseOnHeadRequestError(t *testing.T) {
+	c, err := NewClient("")
+	if err != nil {
+		t.Fatalf("Failed to create client: %v", err)
+	}
+
+	req, err := c.NewRequest(http.MethodHead, "test", nil, nil)
+	if err != nil {
+		t.Fatalf("Failed to create request: %v", err)
+	}
+
+	resp := &http.Response{
+		Request:    req.Request,
+		StatusCode: http.StatusNotFound,
+		Body:       nil,
+	}
+
+	errResp := CheckResponse(resp)
+	if errResp == nil {
+		t.Fatal("Expected error response.")
+	}
+
+	want := "404 Not Found"
+
+	if errResp.Error() != want {
+		t.Errorf("Expected error: %s, got %s", want, errResp.Error())
+	}
+}
+
 func TestRequestWithContext(t *testing.T) {
 	c, err := NewClient("")
 	if err != nil {