Fix Quick Query without an open workspace

extensions/ql-vscode/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [UNRELEASED]
 
+- Fix Quick Query failing to start when no workspace is open.
+
 ## 1.17.8 - 17 July 2026
 
 - Fix a bug where installing or updating the CodeQL CLI could hang indefinitely while extracting the downloaded archive. Extraction now reports an error if a file cannot be written, and aborts with a clear message if no progress is made within the download timeout (for example due to slow or networked storage, or security software). [#4455](https://github.com/github/vscode-codeql/pull/4455)

extensions/ql-vscode/src/local-queries/quick-query-dir.ts

@@ -0,0 +1,12 @@
+import { ensureDir } from "fs-extra";
+import { join } from "path";
+import type { App } from "../common/app";
+
+const QUICK_QUERIES_DIR_NAME = "quick-queries";
+
+export async function getQuickQueriesDir(app: App): Promise<string> {
+  const storagePath = app.workspaceStoragePath ?? app.globalStoragePath;
+  const queriesPath = join(storagePath, QUICK_QUERIES_DIR_NAME);
+  await ensureDir(queriesPath, { mode: 0o700 });
+  return queriesPath;
+}

extensions/ql-vscode/src/local-queries/quick-query.ts

@@ -1,4 +1,4 @@
-import { ensureDir, writeFile, pathExists, readFile } from "fs-extra";
+import { writeFile, pathExists, readFile } from "fs-extra";
 import { dump, load } from "js-yaml";
 import { basename, join } from "path";
 import { window as Window, workspace, Uri } from "vscode";
@@ -11,11 +11,10 @@ import type { ProgressCallback } from "../common/vscode/progress";
 import { UserCancellationException } from "../common/vscode/progress";
 import { getErrorMessage } from "../common/helpers-pure";
 import { FALLBACK_QLPACK_FILENAME, getQlPackFilePath } from "../common/ql";
-import type { App } from "../common/app";
 import type { ExtensionApp } from "../common/vscode/extension-app";
 import type { QlPackFile } from "../packaging/qlpack-file";
+import { getQuickQueriesDir } from "./quick-query-dir";
 
-const QUICK_QUERIES_DIR_NAME = "quick-queries";
 const QUICK_QUERY_QUERY_NAME = "quick-query.ql";
 const QUICK_QUERY_WORKSPACE_FOLDER_NAME = "Quick Queries";
 const QLPACK_FILE_HEADER = "# This is an automatically generated file.\n\n";
@@ -24,16 +23,6 @@ export function isQuickQueryPath(queryPath: string): boolean {
   return basename(queryPath) === QUICK_QUERY_QUERY_NAME;
 }
 
-async function getQuickQueriesDir(app: App): Promise<string> {
-  const storagePath = app.workspaceStoragePath;
-  if (storagePath === undefined) {
-    throw new Error("Workspace storage path is undefined");
-  }
-  const queriesPath = join(storagePath, QUICK_QUERIES_DIR_NAME);
-  await ensureDir(queriesPath, { mode: 0o700 });
-  return queriesPath;
-}
-
 function updateQuickQueryDir(queriesDir: string, index: number, len: number) {
   workspace.updateWorkspaceFolders(index, len, {
     uri: Uri.file(queriesDir),

extensions/ql-vscode/test/unit-tests/local-queries/quick-query.test.ts

@@ -0,0 +1,45 @@
+import type { DirResult } from "tmp";
+import { dirSync } from "tmp";
+import { pathExists } from "fs-extra";
+import { join } from "path";
+import { createMockApp } from "../../__mocks__/appMock";
+import { getQuickQueriesDir } from "../../../src/local-queries/quick-query-dir";
+
+describe("getQuickQueriesDir", () => {
+  let dir: DirResult;
+
+  beforeEach(() => {
+    dir = dirSync({
+      unsafeCleanup: true,
+    });
+  });
+
+  afterEach(() => {
+    dir.removeCallback();
+  });
+
+  it("uses global storage when no workspace is open", async () => {
+    const app = {
+      ...createMockApp({ globalStoragePath: dir.name }),
+      workspaceStoragePath: undefined,
+    };
+
+    const quickQueriesDir = await getQuickQueriesDir(app);
+
+    expect(quickQueriesDir).toBe(join(dir.name, "quick-queries"));
+    expect(await pathExists(quickQueriesDir)).toBe(true);
+  });
+
+  it("prefers workspace storage when a workspace is open", async () => {
+    const workspaceStoragePath = join(dir.name, "workspace-storage");
+    const app = createMockApp({
+      workspaceStoragePath,
+      globalStoragePath: dir.name,
+    });
+
+    const quickQueriesDir = await getQuickQueriesDir(app);
+
+    expect(quickQueriesDir).toBe(join(workspaceStoragePath, "quick-queries"));
+    expect(await pathExists(quickQueriesDir)).toBe(true);
+  });
+});