Reject an empty pr edit title Gitea would ignore

internal/agent/client_test.go

@@ -155,19 +155,19 @@ func TestEditPRSendsOnlySuppliedFields(t *testing.T) {
 func TestEditPRAPIError(t *testing.T) {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/api/v1/repos/unkin/repo/pulls/7", func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusUnprocessableEntity)
-		_, _ = io.WriteString(w, `{"message":"title cannot be empty"}`)
+		w.WriteHeader(http.StatusNotFound)
+		_, _ = io.WriteString(w, `{"message":"pull request does not exist"}`)
 	})
 	srv := httptest.NewServer(mux)
 	defer srv.Close()
 
-	title := ""
+	title := "new title"
 	c := &GiteaClient{BaseURL: srv.URL, Token: "t", HTTP: srv.Client()}
 	_, err := c.EditPR("unkin/repo", 7, EditPROptions{Title: &title})
 	if err == nil {
-		t.Fatal("expected error on 422")
+		t.Fatal("expected error on 404")
 	}
-	if !strings.Contains(err.Error(), "title cannot be empty") {
+	if !strings.Contains(err.Error(), "pull request does not exist") {
 		t.Errorf("error %q should carry the API message", err)
 	}
 }