fix: preserve validation feedback targets

cmd/mxcli/tui/watcher.go

@@ -4,6 +4,7 @@ import (
 	"os"
 	"path/filepath"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -78,6 +79,7 @@ func newWatcher(mprPath, contentsDir string, sender MsgSender) (*Watcher, error)
 
 func (w *Watcher) run(sender MsgSender) {
 	var debounceTimer *time.Timer
+	var debounceSeq atomic.Uint64
 
 	for {
 		select {
@@ -110,7 +112,11 @@ func (w *Watcher) run(sender MsgSender) {
 			if debounceTimer != nil {
 				debounceTimer.Stop()
 			}
+			seq := debounceSeq.Add(1)
 			debounceTimer = time.AfterFunc(watchDebounce, func() {
+				if debounceSeq.Load() != seq {
+					return
+				}
 				sender.Send(MprChangedMsg{})
 			})
 

cmd/mxcli/tui/watcher_test.go

@@ -35,10 +35,11 @@ func TestWatcherDebounce(t *testing.T) {
 	}
 	defer w.Close()
 
-	// Rapidly write 5 times — should debounce into a single message
+	// Rapidly write 5 times — should debounce into a single message.
+	// Keep the burst tighter than the debounce window so slow CI machines do
+	// not accidentally let an intermediate timer fire.
 	for i := range 5 {
 		_ = os.WriteFile(unitFile, []byte{byte('a' + i)}, 0644)
-		time.Sleep(50 * time.Millisecond)
 	}
 
 	// Wait for debounce to fire (500ms + margin)

mdl-examples/bug-tests/358-validation-feedback-targets.mdl

@@ -0,0 +1,67 @@
+-- ============================================================================
+-- Bug #358: Validation feedback object and association targets
+-- ============================================================================
+--
+-- Symptom (before fix):
+--   Microflow `validation feedback` statements can target an object
+--   itself or an association member, not only a scalar attribute. The
+--   MDL grammar accepted only attribute paths, and the formatter
+--   emitted only attribute targets. Round-tripping object-only and
+--   association targets either failed to re-parse the described MDL or
+--   dropped the association name when describing existing Studio Pro
+--   models.
+--
+-- After fix (grammar + formatter only):
+--   - Grammar now accepts `validation feedback $Object message '…';`
+--     (object-only target).
+--   - Grammar treats each path segment of `$Object/Module.Member` as a
+--     qualified name so `Module.Association` stays one association
+--     segment.
+--   - Formatter emits `AssociationName` when `AttributeName` is absent,
+--     preserving association targets when describing existing models.
+--
+-- Scope note:
+--   This PR fixes the parser and the formatter (describe path) so
+--   existing models with object-only or association targets re-parse
+--   and re-describe cleanly. It does NOT extend the builder to make
+--   newly authored object-only targets a valid Studio Pro model — the
+--   builder still emits `Attribute = ""` which Studio Pro rejects with
+--   `[CE0091] No member selected`. Authored validation feedback should
+--   continue to use the attribute form until a follow-up extends the
+--   builder.
+--
+-- Usage (verifies the in-scope fix):
+--   ./bin/mxcli check mdl-examples/bug-tests/358-validation-feedback-targets.mdl
+--   ./bin/mxcli exec mdl-examples/bug-tests/358-validation-feedback-targets.mdl -p app.mpr
+--   ./bin/mxcli -p app.mpr -c "describe microflow BugTest358.MF_ValidateAttr"
+--   The describe output must keep `validation feedback $Customer/Email
+--   message '…';` and `mx check` must report 0 errors.
+--
+--   The OBJECT-ONLY shape `validation feedback $Customer message '…';`
+--   parses and re-describes cleanly (covered by parser/formatter Go tests),
+--   but mx check will still surface `[CE0091]` because the builder is
+--   out of scope here. Authored MDL should keep using the attribute form.
+-- ============================================================================
+
+create module BugTest358;
+
+create entity BugTest358.Customer (
+  Email : string(200)
+);
+/
+
+-- Attribute-target validation feedback — must round-trip cleanly under
+-- describe → exec → describe and pass `mx check`.
+create microflow BugTest358.MF_ValidateAttr (
+  $Customer: BugTest358.Customer
+)
+returns boolean as $Valid
+begin
+  declare $Valid boolean = true;
+  if $Customer/Email = empty then
+    set $Valid = false;
+    validation feedback $Customer/Email message 'Email is required';
+  end if;
+  return $Valid;
+end;
+/