fix(LAN-0): open the move form when jira refuses a move

internal/jira/jira.go

@@ -823,6 +823,20 @@ type RequestError struct {
 
 func (e *RequestError) Error() string { return e.msg }
 
+// Refusal is Jira's reason for turning down a request it understood (400),
+// such as a workflow validator refusing a move: its own messages, or the
+// whole error without them. ok is false for any other error.
+func Refusal(err error) (reason string, ok bool) {
+	re, isRe := errors.AsType[*RequestError](err)
+	if !isRe || re.code != http.StatusBadRequest {
+		return "", false
+	}
+	if len(re.Messages) == 0 {
+		return re.msg, true
+	}
+	return strings.Join(re.Messages, "; "), true
+}
+
 // jiraMessages reads Jira's error body, {"errorMessages": [...], "errors":
 // {field: message}}, as "message; field: message", "" for another body.
 func jiraMessages(body []byte) string {

internal/web/api_core.go

@@ -51,6 +51,11 @@ func init() {
 		key := r.PathValue("key")
 		err = s.Client().DoTransition(ctx, key, b.ID)
 		s.Client().Invalidate(key)
+		// A move the workflow turns down (a validator wanting a comment the
+		// rules can't tell) is 422 with Jira's reason: the board opens its form.
+		if reason, ok := jira.Refusal(err); ok {
+			return nil, httpError{http.StatusUnprocessableEntity, reason}
+		}
 		return nil, err
 	})
 	post("/issues/{key}/rank", func(ctx context.Context, s *Server, r *http.Request) (any, error) {

internal/web/api_edit_test.go

@@ -331,3 +331,28 @@ func TestTransitionWithMentions(t *testing.T) {
 		t.Errorf("update = %s", b)
 	}
 }
+
+// TestTransitionRefused: a move Jira's workflow turns down (a validator that
+// wants a comment the rules didn't show) answers 422 with Jira's reason, so
+// the board opens the move's form instead of only reporting the failure.
+func TestTransitionRefused(t *testing.T) {
+	fake := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodPost && strings.HasSuffix(r.URL.Path, "/transitions") {
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusBadRequest)
+			_, _ = w.Write([]byte(`{"errorMessages":["Add a comment, or comment first and then move the work item (within 10 minutes)."],"errors":{}}`))
+			return
+		}
+		http.NotFound(w, r)
+	}))
+	t.Cleanup(fake.Close)
+	ts := issueServer(t, fake.URL)
+	var out struct{ Error string }
+	code := issueCall(t, "POST", ts.URL+"/api/issues/DEMO-1/transition", map[string]any{"ID": "13"}, &out)
+	if code != http.StatusUnprocessableEntity {
+		t.Fatalf("transition: %d, want 422", code)
+	}
+	if want := "Add a comment, or comment first and then move the work item (within 10 minutes)."; out.Error != want {
+		t.Errorf("error = %q, want %q", out.Error, want)
+	}
+}

internal/web/static/js/views/board.js

@@ -1076,7 +1076,10 @@ export default function mount(el, { app, params, query, scope, context, toolbar,
       bus.emit('issue:changed', { key: card.Key, what: card.Key + ' → ' + t.Name });
       if (done) confetti(app, [...main.querySelectorAll('.bd-lane-head.kdone')].find(e => e.querySelector('.bd-lane-name').textContent === col.Name));
     } catch (e) {
-      revertCard(card.Key, before); ui.toast(T('Could not move %s: %s', card.Key, e.message), { kind: 'err' });
+      revertCard(card.Key, before);
+      // Jira refused the bare move (422: a validator wants a comment the rules didn't show): open its form with Jira's reason.
+      if (e.status === 422 && meta && meta.Fields && meta.Fields.length) return import('./fields.js').then(m => m.moveForm(app, card.Key, { ...meta, Message: e.message }));
+      ui.toast(T('Could not move %s: %s', card.Key, e.message), { kind: 'err' });
     }
   }
   // A drop into another swimlane gives the card that band's assignee or epic, as Jira's board (TUI jiraSetBand).