fix(mongodb): keep local value filters across page size changes

apps/desktop/src/components/document/DocumentBrowser.vue

@@ -339,7 +339,20 @@ function documentDataSignature(): string | undefined {
   }
 }
 
-const documentLocalColumnFilterRestoreKey = computed(() => documentDataSignature());
+// Local value filters describe column values, not the rows that happen to be
+// loaded, so paging and page-size changes must not drop them. Only a new query
+// (collection, filter or sort) invalidates the snapshot; restored filters are
+// mapped back by column name, so a changed column set is handled as well.
+function documentLocalColumnFilterSignature(): string | undefined {
+  try {
+    return JSON.stringify([documentStoreProvider.value.kind, props.connectionId, props.database, props.collection, currentDocumentFilter() ?? null, currentDocumentSortJson(sortInput.value) ?? null]);
+  } catch {
+    // Malformed filter/sort JSON: nothing stable to key filters against.
+    return undefined;
+  }
+}
+
+const documentLocalColumnFilterRestoreKey = computed(() => documentLocalColumnFilterSignature());
 
 let loadedDocumentDataSignature: string | undefined;
 
@@ -391,13 +404,11 @@ function handleLocalColumnFiltersChange(filters: SerializedDataGridLocalColumnFi
   persistDocumentBrowserState({ includeData: true });
 }
 
-// Keep these sources in lockstep with documentDataSignature(): every input that
-// invalidates held rows (including pageSize and the infinite-scroll setting, which
-// can change mid-session at page 0 without moving `page`) must also drop the
-// local-filter snapshot, or a tab switch would replay filters the user watched
-// DataGrid clear on its own restore-key change.
+// Keep these sources in lockstep with documentLocalColumnFilterSignature(): a
+// changed query means the local-filter snapshot no longer describes what the
+// user is looking at.
 watch(
-  [filterInput, sortInput, appliedDocumentFilter, page, pageSize, () => settingsStore.editorSettings.infiniteScroll],
+  [filterInput, sortInput, appliedDocumentFilter],
   () => {
     localColumnFilters.value = {};
     localColumnFilterColumns.value = undefined;
@@ -405,6 +416,8 @@ watch(
   },
   { deep: true },
 );
+// Paging and page-size changes reload rows, but the local value filters stay put.
+watch([page, pageSize, () => settingsStore.editorSettings.infiniteScroll], () => persistDocumentBrowserState());
 watch(documentFilterRules, () => persistDocumentBrowserState(), { deep: true });
 
 // Seed the grid from the cached page so a tab switch costs no round trip

apps/desktop/src/components/document/__tests__/DocumentBrowserTabState.spec.ts

@@ -399,16 +399,17 @@ describe("DocumentBrowser tab state (tab switch persistence)", () => {
     expect(dataGrid.localColumnFilterColumns).toBeUndefined();
   });
 
-  it("clears mongodb local column filters when the page size changes mid-session", async () => {
+  it("keeps mongodb local column filters when the page size changes mid-session", async () => {
     await mountBrowser({ stateKey: "tab-local-filters-page-size" });
     dataGrid.localFiltersChange!({ "1": ["str:OpenGate"] });
     await flushUi();
     expect(dataGrid.localColumnFilters).toEqual({ "1": ["str:OpenGate"] });
 
-    // Page stays at 0 for a page-size change, so only the pageSize input invalidates the snapshot.
+    // A page-size change reloads rows, but the value filter is about columns, not rows.
     await dataGrid.paginate!(0, 10);
     await flushUi();
-    expect(dataGrid.localColumnFilters).toEqual({});
+    expect(dataGrid.localColumnFilters).toEqual({ "1": ["str:OpenGate"] });
+    expect(dataGrid.localColumnFilterColumns).toEqual(["_id", "name"]);
 
     app!.unmount();
     app = null;
@@ -416,8 +417,8 @@ describe("DocumentBrowser tab state (tab switch persistence)", () => {
     await flushUi();
     await mountBrowser({ stateKey: "tab-local-filters-page-size" });
 
-    expect(dataGrid.localColumnFilters).toEqual({});
-    expect(dataGrid.localColumnFilterColumns).toBeUndefined();
+    expect(dataGrid.localColumnFilters).toEqual({ "1": ["str:OpenGate"] });
+    expect(dataGrid.localColumnFilterColumns).toEqual(["_id", "name"]);
   });
 
   it("still forces a real reload from the refresh button after a restore", async () => {