fix(document): surface filter rejection reason in builder

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

@@ -321,6 +321,9 @@ type DocumentGridChanges = {
   rows: MongoInputValue[][];
 };
 const documentFilterBuilderOpen = ref(false);
+/// Why an Apply click did not filter. The shared `error` banner lives in the document pane, which
+/// the open filter popover covers, so a rejected rule there reads as a dead button.
+const documentFilterBuilderError = ref("");
 const documentFilterFieldPopoverOpen = ref<Record<string, boolean>>({});
 const documentFilterFieldSearch = ref<Record<string, string>>({});
 const documentFilterRules = ref<DocumentFilterRule[]>(restoredDocumentBrowserState?.documentFilterRules ?? []);
@@ -908,12 +911,14 @@ function documentFilterFieldKindLabel(kind: DocumentFieldPathNode["kind"]): stri
 }
 
 function removeDocumentFilterRule(ruleId: string) {
+  documentFilterBuilderError.value = "";
   documentFilterRules.value = documentFilterRules.value.filter((rule) => rule.id !== ruleId);
   setDocumentFilterFieldPopoverOpen(ruleId, false);
   if (documentFilterRules.value.length === 0) appliedDocumentFilter.value = null;
 }
 
 function updateDocumentFilterRule(ruleId: string, patch: Partial<DocumentFilterRule>) {
+  documentFilterBuilderError.value = "";
   documentFilterRules.value = documentFilterRules.value.map((rule) => {
     if (rule.id !== ruleId) return rule;
     const next = { ...rule, ...patch };
@@ -947,6 +952,7 @@ function elasticsearchQueryTypeLabel(queryType: ElasticsearchQueryType): string
 }
 
 function resetDocumentFilterBuilder() {
+  documentFilterBuilderError.value = "";
   appliedDocumentFilter.value = null;
   documentFilterFieldPopoverOpen.value = {};
   documentFilterFieldSearch.value = {};
@@ -1399,9 +1405,10 @@ async function applyDocumentStructuredFilters() {
       }))
       .filter((item): item is { rule: DocumentFilterRule; condition: Record<string, unknown> } => !!item.condition);
   } catch (e) {
-    error.value = e instanceof Error ? e.message : String(e);
+    documentFilterBuilderError.value = e instanceof Error ? e.message : String(e);
     return;
   }
+  documentFilterBuilderError.value = "";
   error.value = "";
   const structured = combineDocumentFilterConditions(
     items.map((item) => item.condition),
@@ -3186,6 +3193,10 @@ defineExpose({ focusSearch });
                   {{ t("grid.filterBuilderEmpty") }}
                 </div>
 
+                <p v-if="documentFilterBuilderError" data-document-filter-builder-error class="text-xs text-destructive">
+                  {{ documentFilterBuilderError }}
+                </p>
+
                 <div class="flex items-center justify-between gap-2">
                   <Button variant="ghost" size="sm" class="h-7 px-2 text-xs" @click="addDocumentFilterRule">
                     <Plus class="mr-1 h-3.5 w-3.5" />

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

@@ -1052,6 +1052,53 @@ describe("DocumentBrowser MongoDB filter value types", () => {
     expect(JSON.parse(filter)).toEqual({ _id: "1" });
   });
 
+  it("keeps the filter builder open and says why a rejected rule did not apply", async () => {
+    app?.unmount();
+    backend.documentFindDocuments.mockReset();
+    backend.documentFindDocuments.mockResolvedValue({
+      documents: [{ _id: 1, title: "Numeric id" }],
+      raw_documents: [],
+      total: 1,
+      total_is_exact: true,
+    });
+    app = createApp(DocumentBrowser, {
+      connectionId: "mongo-1",
+      database: "test",
+      collection: "numeric_ids",
+      databaseType: "mongodb",
+    });
+    app.mount(root!);
+    await flushUi();
+
+    root!.querySelector<HTMLButtonElement>('[data-testid="data-grid"] button')!.click();
+    await flushUi();
+
+    const valueInput = document.body.querySelector<HTMLInputElement>('input[placeholder="grid.filterBuilderValue"]')!;
+    valueInput.value = "abc";
+    valueInput.dispatchEvent(new Event("input", { bubbles: true }));
+    await flushUi();
+
+    const callsBeforeApply = backend.documentFindDocuments.mock.calls.length;
+    buttonWithText("grid.applyFilter").click();
+    await flushUi();
+
+    // The shared error banner sits in the document pane, which this popover covers, so the
+    // reason has to appear inside the builder or the click reads as a dead button.
+    expect(document.body.querySelector("[data-document-filter-builder-error]")?.textContent).toContain("number");
+    expect(document.body.querySelector('[data-testid="popover-content"]')).not.toBeNull();
+    expect(backend.documentFindDocuments.mock.calls.length).toBe(callsBeforeApply);
+
+    // Correcting the rule drops the stale message.
+    valueInput.value = "1";
+    valueInput.dispatchEvent(new Event("input", { bubbles: true }));
+    await flushUi();
+    expect(document.body.querySelector("[data-document-filter-builder-error]")).toBeNull();
+
+    buttonWithText("grid.applyFilter").click();
+    await flushUi();
+    expect(JSON.parse(backend.documentFindDocuments.mock.calls.at(-1)?.[5])).toEqual({ _id: 1 });
+  });
+
   it("exposes the applicable shared table view options", async () => {
     app?.unmount();
     app = createApp(DocumentBrowser, {