fix(launch): accessible name for the launch trigger + first launch-popover coverage

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "makefile.configureOnOpen": false
+}

CHANGELOG.md

@@ -20,6 +20,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- The notebook-launch toolbar trigger now has an accessible name (`aria-label="Launch notebook"`); previously it exposed no name to assistive technology. Added alongside the first regression coverage of the launch popover (Colab URL + default selection — BinderHub was deliberately not added, see [#26](https://github.com/QuantEcon/quantecon-theme.mystmd/issues/26)).
+
 ### Added
 - Per-PR rendered previews on GitHub Pages (`.github/workflows/preview.yml`): each PR statically builds the real `lecture-python-programming` lectures with the candidate theme (`myst build --html`, including the build-time Jupyter Book → MyST upgrade) and publishes to `gh-pages` at `pr-preview/pr-<n>/` with a sticky link comment and teardown on close. Self-contained on `GITHUB_TOKEN` — no external preview service.
 

PLAN.md

@@ -272,8 +272,14 @@ stripping) + `docs/user/launch.md`.
       in (`PageContent.tsx` uses `ExecuteScopeProvider`, `NotebookToolbar`). Confirm/enable
       `myst.yml` `project.jupyter`/`thebe` config path and surface a "live compute" toggle
       consistent with the toolbar.
-- [ ] **BinderHub:** add a Binder option to the `LaunchButton` radio group; build
-      `…/v2/gh/{org}/{repo}/{branch}?urlpath=…` URLs.
+- [x] ~~**BinderHub:** add a Binder option to the `LaunchButton` radio group~~
+      **Decided against (2026-06-12):** BinderHub proved flaky in practice, and Colab
+      is the launch target QuantEcon standardises on — primarily because it provides
+      **GPU access** for the lectures that need it. #26 stays open as a demand-driven
+      future request (an implementation existed in PR #86 and was stripped before
+      merge — recoverable from that history if demand appears). The Private
+      JupyterHub option remains for now; its possible removal (collapsing the
+      launcher to a direct Colab button) is tracked in #87.
 - [ ] Generalise the hardcoded `.notebooks` suffix and `main` branch
       (`LaunchButton.tsx:9–11`) into config read from project frontmatter / `myst.yml`,
       so non-default branches and naming work.

README.md

@@ -53,6 +53,11 @@ downloads:
 
 The launch notebooks capability has been developed to mirror capabilities in the previous QuantEcon theme. It is assumed that the `.notebooks` suffix convention for repository naming is used when launching both Google Colab and Private Jupyter Hub sessions.
 
+Colab is the primary launch target (it provides GPU access for the lectures that
+need it). BinderHub is deliberately not offered — it proved flaky in practice;
+see issue [#26](https://github.com/QuantEcon/quantecon-theme.mystmd/issues/26),
+kept open as a demand-driven future request.
+
 ## Usage with MyST
 
 Point your project's `site.template` at a **pinned release** zip:

app/components/toolbar/LaunchButton.tsx

@@ -103,7 +103,7 @@ function LaunchPanel() {
 export function LaunchButton({ size, showLabel }: { size: number; showLabel?: boolean }) {
   return (
     <Popover.Root>
-      <Popover.Trigger className="flex items-center cursor-pointer">
+      <Popover.Trigger aria-label="Launch notebook" className="flex items-center cursor-pointer">
         <Tooltip label="Launch Notebook">
           <CirclePlay
             className="opacity-90 hover:scale-110"

tests/visual/theme.spec.ts

@@ -51,4 +51,39 @@ test.describe("QuantEcon theme — visual regression", () => {
       animations: "disabled",
     });
   });
+
+  // Launch popover: Colab is the default and primary target (BinderHub is
+  // deliberately not offered — #26). window.open is stubbed so the launch URL
+  // assertion is deterministic and offline; the URL's repo part comes from the
+  // fixture's `github` field, so only the stable pieces (host, .notebooks
+  // convention, branch, path) are pinned.
+  test("launch-colab", async ({ page }, testInfo) => {
+    test.skip(
+      testInfo.project.name !== "desktop-chrome",
+      "the launch popover lives in the desktop toolbar; mobile wraps it in MobileActionsMenu"
+    );
+    await page.goto("/notebook", { waitUntil: "domcontentloaded" });
+    await settle(page);
+    await page.evaluate(() => {
+      (window as any).__opened = [];
+      window.open = (url?: string | URL) => {
+        (window as any).__opened.push(String(url));
+        return null;
+      };
+    });
+    await page.getByRole("button", { name: "Launch notebook" }).first().click();
+    const dialog = page.getByRole("dialog");
+    await expect(dialog.getByRole("radio", { name: "Google Colab" })).toBeChecked();
+    await expect(dialog.getByRole("radio", { name: "Private" })).toBeVisible();
+    await expect(page).toHaveScreenshot("launch-open.png", {
+      maxDiffPixelRatio: 0.01,
+      animations: "disabled",
+    });
+    await dialog.getByRole("button", { name: "Launch Notebook" }).click();
+    const opened = await page.evaluate(() => (window as any).__opened);
+    expect(opened).toHaveLength(1);
+    expect(opened[0]).toMatch(
+      /^https:\/\/colab\.research\.google\.com\/github\/QuantEcon\/[\w.-]+\.notebooks\/blob\/main\/notebook\.ipynb$/
+    );
+  });
 });