fix: lists and list items deleted on another device are now deleted locally

src/stores/__tests__/lists.spec.ts

@@ -123,6 +123,9 @@ describe('useListsStore', () => {
 
   it('creates a list locally, queues a sync entry, and remaps the id after a successful sync', async () => {
     listsApiMocks.createListApi.mockResolvedValueOnce({ id: 'server-id-1', name: 'Groceries' })
+    // The chained pullFromServer() call needs to report the just-created list
+    // back, otherwise it would look like the server deleted it.
+    listsApiMocks.getListsApi.mockResolvedValueOnce([{ id: 'server-id-1', name: 'Groceries' }])
 
     const store = useListsStore()
     const localList = await store.createList('Groceries', [])
@@ -264,6 +267,55 @@ describe('useListsStore', () => {
     expect(store.listItems.find((item) => item.id === 'server-item-1')).toBeDefined()
   })
 
+  it('deletes a previously synced list locally when it is missing from the server', async () => {
+    const store = useListsStore()
+    await fakeDb.lists.put({ id: 'server-list-1', name: 'Groceries', pendingSync: false })
+    await fakeDb.listItems.put({
+      id: 'server-item-1',
+      list_id: 'server-list-1',
+      title: 'Milk',
+      pendingSync: false,
+    })
+    await store.refresh()
+
+    listsApiMocks.getListsApi.mockResolvedValueOnce([])
+
+    await store.pullFromServer()
+
+    expect(store.lists.find((list) => list.id === 'server-list-1')).toBeUndefined()
+    expect(store.listItems.find((item) => item.id === 'server-item-1')).toBeUndefined()
+  })
+
+  it('deletes a previously synced list item locally when it is missing from the server', async () => {
+    const store = useListsStore()
+    await fakeDb.listItems.put({
+      id: 'server-item-2',
+      list_id: 'server-list-1',
+      title: 'Bread',
+      pendingSync: false,
+    })
+    await store.refresh()
+
+    listsApiMocks.getListItemsApi.mockResolvedValueOnce([])
+
+    await store.pullListItems('server-list-1')
+
+    expect(store.listItems.find((item) => item.id === 'server-item-2')).toBeUndefined()
+  })
+
+  it('does not delete a locally pending list even when it is missing from the server', async () => {
+    listsApiMocks.createListApi.mockImplementation(() => new Promise(() => {}))
+
+    const store = useListsStore()
+    const localList = await store.createList('Local only')
+
+    listsApiMocks.getListsApi.mockResolvedValueOnce([])
+
+    await store.pullFromServer()
+
+    expect(store.lists.find((list) => list.id === localList.id)).toBeDefined()
+  })
+
   it('does not overwrite a locally pending list with stale server data', async () => {
     listsApiMocks.createListApi.mockImplementation(() => new Promise(() => {}))
 

src/stores/lists.ts

@@ -369,6 +369,7 @@ export const useListsStore = defineStore('lists', () => {
 
     try {
       const serverLists = await getListsApi()
+      const serverListIds = new Set(serverLists.map((serverList) => serverList.id))
 
       for (const serverList of serverLists) {
         const existingList = await db.lists.get(serverList.id)
@@ -376,6 +377,23 @@ export const useListsStore = defineStore('lists', () => {
           await db.lists.put({ ...serverList, pendingSync: false })
         }
       }
+
+      // Lists that were already synced but are no longer reported by the
+      // server have been deleted there (e.g. from another device), so
+      // remove them locally too, along with their items. Lists that still
+      // have pending local changes (not yet synced, e.g. a not-yet-pushed
+      // "createList") are left alone since the server doesn't know about
+      // them yet.
+      const localLists = await db.lists.toArray()
+      for (const localList of localLists) {
+        if (!localList.pendingSync && !serverListIds.has(localList.id)) {
+          await db.lists.delete(localList.id)
+          const orphanedItems = await db.listItems.where('list_id').equals(localList.id).toArray()
+          for (const item of orphanedItems) {
+            await db.listItems.delete(item.id)
+          }
+        }
+      }
     } catch (err) {
       error.value = err instanceof Error ? err.message : 'Failed to load lists from server'
     } finally {
@@ -391,12 +409,25 @@ export const useListsStore = defineStore('lists', () => {
 
     try {
       const serverItems = await getListItemsApi(listId)
+      const serverItemIds = new Set(serverItems.map((serverItem) => serverItem.id))
+
       for (const serverItem of serverItems) {
         const existingItem = await db.listItems.get(serverItem.id)
         if (!existingItem || !existingItem.pendingSync) {
           await db.listItems.put({ ...serverItem, pendingSync: false })
         }
       }
+
+      // Items that were already synced but are no longer reported by the
+      // server for this list have been deleted there, so remove them
+      // locally too. Items with pending local changes are left alone since
+      // the server doesn't know about them yet.
+      const localItems = await db.listItems.where('list_id').equals(listId).toArray()
+      for (const localItem of localItems) {
+        if (!localItem.pendingSync && !serverItemIds.has(localItem.id)) {
+          await db.listItems.delete(localItem.id)
+        }
+      }
     } catch (err) {
       error.value = err instanceof Error ? err.message : 'Failed to load list items from server'
     } finally {