fix(debate): keep a pin saved while an older load was in flight

A pin load reads the table and answers later. If a pin was still saving
when the load read the table, but finished before the load answered, the
load's older rows replaced it and the pin vanished from the screen.

A load now also replays every change that was still saving when it
started.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: Programcode

src/lib/stores/debate-context-store.ts

@@ -54,7 +54,8 @@ function ensureOverride(current: DebateContextOverride | undefined, debateId: st
 }
 
 // Every local pin change, per debate and in order. A load replays the changes
-// it may have missed: ones made after it started, and ones still saving.
+// it may have missed: ones made after it started, and ones that were still
+// saving at any point during the load, because its read may predate them.
 // `before` is the result's state before this change; if the change fails, the
 // result goes back to it.
 interface PinChange { seq: number; ref: DebateOutputRef; pinned: boolean; before: boolean; saving: boolean }
@@ -81,6 +82,7 @@ export const useDebateContextStore = create<DebateContextState>()((set, get) =>
   loadPins: async (debateId) => {
     const startedAt = pinSeq;
     const generation = pinGeneration;
+    const savingAtStart = new Set((pinChanges[debateId] ?? []).filter((change) => change.saving));
     const { data, error } = await supabase
       .from('debate_context_pins')
       .select('item_kind,item_id')
@@ -97,7 +99,7 @@ export const useDebateContextStore = create<DebateContextState>()((set, get) =>
         ? [{ kind: row.item_kind as DebateContextOutputKind, id: row.item_id }]
         : []);
     for (const change of pinChanges[debateId] ?? []) {
-      if (change.seq > startedAt || change.saving) pins = withPin(pins, change.ref, change.pinned);
+      if (change.seq > startedAt || change.saving || savingAtStart.has(change)) pins = withPin(pins, change.ref, change.pinned);
     }
     set((state) => ({
       pins: { ...state.pins, [debateId]: pins },

src/test/debate/debate-context.test.tsx

@@ -288,6 +288,25 @@ describe('Pinned results', () => {
     expect(useDebateContextStore.getState().pins[TEST_DEBATE_ID]).toEqual([caseRef, attackRef]);
   });
 
+  it('keeps a pin that finished saving while an older load was in flight', async () => {
+    const insert = deferred<{ error: null }>();
+    const load = deferred<{ data: unknown; error: null }>();
+    supabaseMock.from
+      .mockImplementationOnce((() => ({ insert: () => insert.promise })) as never)
+      .mockImplementationOnce((() => ({ select: () => ({ eq: () => load.promise }) })) as never);
+
+    const pinning = useDebateContextStore.getState().togglePin(TEST_DEBATE_ID, caseRef);
+    await new Promise((done) => setTimeout(done, 0));
+    // The load reads the table before the insert commits, then answers after it.
+    const loading = useDebateContextStore.getState().loadPins(TEST_DEBATE_ID);
+    insert.resolve({ error: null });
+    await pinning;
+    load.resolve({ data: [], error: null });
+    await loading;
+
+    expect(useDebateContextStore.getState().pins[TEST_DEBATE_ID]).toEqual([caseRef]);
+  });
+
   it('saves a quick pin and unpin of the same result in the order they were made', async () => {
     const insert = deferred<{ error: null }>();
     const calls: string[] = [];