Add webhook assigning test and fix possible bug (#34420)

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Author: lunny

services/issue/assignee.go

@@ -54,6 +54,8 @@ func ToggleAssigneeWithNotify(ctx context.Context, issue *issues_model.Issue, do
 	if err != nil {
 		return false, nil, err
 	}
+	issue.AssigneeID = assigneeID
+	issue.Assignee = assignee
 
 	notify_service.IssueChangeAssignee(ctx, doer, issue, assignee, removed, comment)
 

tests/integration/issue_test.go

@@ -151,6 +151,15 @@ func testNewIssue(t *testing.T, session *TestSession, user, repo, title, content
 	return issueURL
 }
 
+func testIssueAssign(t *testing.T, session *TestSession, repoLink string, issueID, assigneeID int64) {
+	req := NewRequestWithValues(t, "POST", fmt.Sprintf(repoLink+"/issues/assignee?issue_ids=%d", issueID), map[string]string{
+		"_csrf":  GetUserCSRFToken(t, session),
+		"id":     strconv.FormatInt(assigneeID, 10),
+		"action": "", // empty action means assign
+	})
+	session.MakeRequest(t, req, http.StatusOK)
+}
+
 func testIssueAddComment(t *testing.T, session *TestSession, issueURL, content, status string) int64 {
 	req := NewRequest(t, "GET", issueURL)
 	resp := session.MakeRequest(t, req, http.StatusOK)