Ignore response body during HEAD request error handling

gitlab.go

@@ -953,8 +953,13 @@ 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)
+	str := fmt.Sprintf("%s %s: %d", e.Response.Request.Method, url, e.Response.StatusCode)
+	if e.Message != "" {
+		str += " " + e.Message
+	}
+
+	return str
 }
 
 // CheckResponse checks the API response for errors, and returns them if present.
@@ -965,6 +970,11 @@ func CheckResponse(r *http.Response) error {
 	}
 
 	errorResponse := &ErrorResponse{Response: r}
+
+	if r.Request.Method == http.MethodHead {
+		return errorResponse
+	}
+
 	data, err := io.ReadAll(r.Body)
 	if err == nil && data != nil {
 		errorResponse.Body = data

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 := "HEAD https://gitlab.com/api/v4/test: 404"
+
+	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 {