Snippet naming: content-derived on publish, frozen on explicit rename

src/app/components/SnippetLibrary.test.tsx

@@ -89,6 +89,66 @@ describe('SnippetLibrary metadata panel (spec §02)', () => {
     expect(useSnippetStore.getState().snippets[0].name).toBe('Renamed');
   });
 
+  test('a publish-derived rename is adopted by the panel, not reverted by its auto-save', () => {
+    // Regression: the panel's local name state lagged a publish rename, so its
+    // debounced auto-save wrote the stale default back — the rename flickered
+    // for ~400ms in the list and then undid itself.
+    vi.useFakeTimers();
+    const s = createSnippet({ id: 'a', now: new Date('2026-01-01T00:00:00Z') }); // auto name
+    useSnippetStore.getState().hydrate([s], 'a');
+
+    act(() => {
+      root.render(<SnippetLibrary />);
+    });
+
+    act(() => {
+      useSnippetStore
+        .getState()
+        .updateDraft(
+          JSON.stringify({
+            mark: 'bar',
+            encoding: { x: { field: 'Region' }, y: { aggregate: 'count' } },
+          }),
+        );
+      useSnippetStore.getState().publish(new Date('2026-02-01T00:00:00Z'));
+    });
+
+    expect(nameInput().value).toBe('Bar chart of count by Region');
+    act(() => {
+      vi.advanceTimersByTime(1000); // any pending auto-save settles
+    });
+    expect(useSnippetStore.getState().snippets[0].name).toBe('Bar chart of count by Region');
+  });
+
+  test('a name edit in progress survives a publish rename (user text wins)', () => {
+    vi.useFakeTimers();
+    const s = createSnippet({ id: 'a', now: new Date('2026-01-01T00:00:00Z') });
+    useSnippetStore.getState().hydrate([s], 'a');
+
+    act(() => {
+      root.render(<SnippetLibrary />);
+    });
+
+    act(() => typeInto(nameInput(), 'My Chart')); // diverged, debounce pending
+    act(() => {
+      useSnippetStore
+        .getState()
+        .updateDraft(
+          JSON.stringify({
+            mark: 'bar',
+            encoding: { x: { field: 'Region' }, y: { aggregate: 'count' } },
+          }),
+        );
+      useSnippetStore.getState().publish();
+    });
+
+    expect(nameInput().value).toBe('My Chart'); // not clobbered by the derived name
+    act(() => {
+      vi.advanceTimersByTime(1000);
+    });
+    expect(useSnippetStore.getState().snippets[0].name).toBe('My Chart');
+  });
+
   test('does not loop on a search/sort state change (render-loop guard)', async () => {
     // A selector that returned a fresh filtered array would re-render forever
     // (MEMORY → "Zustand stable selectors"); the component derives via useMemo.

src/app/components/SnippetLibrary.tsx

@@ -99,6 +99,19 @@ function SnippetMeta({
   const [name, setName] = useState(snippet.name);
   const [comment, setCommentLocal] = useState(snippet.comment);
 
+  // The store can rename underneath this panel (publish's content-derived
+  // naming, spec §03D). Adopt the new store name unless the local field has
+  // diverged — i.e. the user is mid-edit, and their text wins. Without this,
+  // the stale local value differs from the store and the auto-save below
+  // writes the old name right back, silently undoing the publish rename.
+  const lastStoreName = useRef(snippet.name);
+  useEffect(() => {
+    if (snippet.name === lastStoreName.current) return;
+    const previous = lastStoreName.current;
+    lastStoreName.current = snippet.name;
+    setName((local) => (local === previous ? snippet.name : local));
+  }, [snippet.name]);
+
   useEffect(() => {
     if (name === snippet.name) return;
     const t = setTimeout(() => renameSnippet(snippet.id, name), META_AUTOSAVE_MS);

src/app/stores/ChartBuilderStore.ts

@@ -538,6 +538,9 @@ export const useChartBuilderStore = create<ChartBuilderState>((set, get) => ({
     // to its dataset (§09F) without extra wiring. Provenance kept in meta (§06).
     useSnippetStore.getState().createSnippet({
       name,
+      // Generated, not chosen: stays in the auto naming tier, so publish keeps
+      // the name tracking the spec until the user renames (spec §02 → Naming).
+      nameSource: 'auto',
       spec: specText,
       now,
       meta: { createdWith: 'chart-builder', builtFromDataset: config.datasetName },

src/app/stores/SnippetStore.test.ts

@@ -225,6 +225,98 @@ describe('editorView + selectShownText (spec §03D)', () => {
   });
 });
 
+describe('publish — content-derived naming (untouched default names only)', () => {
+  const namableSpec = JSON.stringify({
+    mark: 'bar',
+    encoding: { x: { field: 'Ship Mode' }, y: { aggregate: 'count' } },
+  });
+
+  test('publishing upgrades an untouched timestamp name to a content-derived one', () => {
+    const a = createSnippet({ id: 'a', now: new Date('2026-01-01T00:00:00Z') });
+    store().hydrate([a], 'a');
+
+    store().updateDraft(namableSpec);
+    store().publish(new Date('2026-02-01T00:00:00Z'));
+
+    expect(selectActiveSnippet(store())?.name).toBe('Bar chart of count by Ship Mode');
+  });
+
+  test('a user-chosen name is never overwritten', () => {
+    const a = createSnippet({ id: 'a', name: 'My Chart' });
+    store().hydrate([a], 'a');
+
+    store().updateDraft(namableSpec);
+    store().publish();
+
+    expect(selectActiveSnippet(store())?.name).toBe('My Chart');
+  });
+
+  test('an undescribable spec keeps the default name', () => {
+    const a = createSnippet({ id: 'a', now: new Date('2026-01-01T00:00:00Z') });
+    store().hydrate([a], 'a');
+
+    store().updateDraft('{"a":2}');
+    store().publish();
+
+    expect(selectActiveSnippet(store())?.name).toBe(a.name);
+  });
+
+  test('an auto name keeps tracking the spec across publishes', () => {
+    const a = createSnippet({ id: 'a', now: new Date('2026-01-01T00:00:00Z') });
+    store().hydrate([a], 'a');
+
+    store().updateDraft(namableSpec);
+    store().publish();
+    expect(selectActiveSnippet(store())?.name).toBe('Bar chart of count by Ship Mode');
+
+    store().updateDraft(
+      JSON.stringify({
+        mark: 'line',
+        encoding: { x: { field: 'date' }, y: { aggregate: 'sum', field: 'revenue' } },
+      }),
+    );
+    store().publish();
+    expect(selectActiveSnippet(store())?.name).toBe('Line chart of sum of revenue by date');
+  });
+
+  test('a legacy record whose name matches its own derivation stays in the auto tier', () => {
+    // Records written before nameSource existed: a name identical to what the
+    // app derives from the published spec is provably app-picked, so adding a
+    // title and publishing must adopt it (not stay frozen).
+    const legacy = {
+      ...createSnippet({ id: 'a', spec: namableSpec, now: new Date('2026-01-01T00:00:00Z') }),
+      name: 'Bar chart of count by Ship Mode',
+      nameSource: undefined,
+    };
+    store().hydrate([legacy], 'a');
+
+    store().updateDraft(
+      JSON.stringify({
+        title: 'Shipments by mode',
+        mark: 'bar',
+        encoding: { x: { field: 'Ship Mode' }, y: { aggregate: 'count' } },
+      }),
+    );
+    store().publish();
+
+    expect(selectActiveSnippet(store())?.name).toBe('Shipments by mode');
+  });
+
+  test('an explicit rename freezes the name against later publishes', () => {
+    const a = createSnippet({ id: 'a', now: new Date('2026-01-01T00:00:00Z') });
+    store().hydrate([a], 'a');
+
+    store().updateDraft(namableSpec);
+    store().publish();
+    store().renameSnippet('a', 'My Chart');
+
+    store().updateDraft(JSON.stringify({ title: 'Something else', mark: 'bar' }));
+    store().publish();
+
+    expect(selectActiveSnippet(store())?.name).toBe('My Chart');
+  });
+});
+
 describe('publish — datasetRefs recomputation', () => {
   const refSpec = (name: string) => JSON.stringify({ data: { name }, mark: 'bar' });
 

src/app/stores/SnippetStore.ts

@@ -20,7 +20,9 @@
 import { create } from 'zustand';
 import {
   createSnippet,
+  deriveSnippetName,
   duplicateSnippet as duplicateSnippetRecord,
+  isAutoNamed,
   type CreateSnippetOptions,
   type Snippet,
 } from '@core/snippet';
@@ -260,7 +262,12 @@ export const useSnippetStore = create<SnippetState>((set, get) => ({
       if (!target || target.name === name) return s; // unknown id or no change
       const modified = (now ?? new Date()).toISOString();
       return {
-        snippets: s.snippets.map((x) => (x.id === id ? { ...x, name, modified } : x)),
+        // An explicit rename freezes the name (`nameSource: 'user'`) — publish's
+        // content-derived naming only ever rewrites auto-picked names (spec §02
+        // → Naming & Tags).
+        snippets: s.snippets.map((x) =>
+          x.id === id ? { ...x, name, nameSource: 'user' as const, modified } : x,
+        ),
       };
     });
   },
@@ -424,9 +431,16 @@ export const useSnippetStore = create<SnippetState>((set, get) => ({
         s.id === activeSnippetId
           ? // Promote the draft and recompute datasetRefs from the now-published
             // spec, so the bidirectional snippet↔dataset link mirrors reality
-            // (spec §03D, docs/architecture/07 §3).
+            // (spec §03D, docs/architecture/07 §3). An auto-picked name keeps
+            // tracking the published content — title, else mark + encodings —
+            // and stays auto so the next publish tracks again; a user-chosen
+            // name (`nameSource: 'user'`) is never rewritten (spec §03D →
+            // Publish, §02 → Naming & Tags).
             {
               ...s,
+              ...(isAutoNamed(s)
+                ? { name: deriveSnippetName(s.draftSpec) ?? s.name, nameSource: 'auto' as const }
+                : {}),
               spec: s.draftSpec,
               datasetRefs: recomputeDatasetRefs(s.draftSpec),
               modified,