test(queue): pin the back stack and the mount that was not taken

Nine tests, and the header says which of them reproduce the defect:
three do, and the other six cannot. "The entry is not orphaned" and "a
docked column is not in the stack" are both vacuously true of a build
that pushes no entry at all. That was established by reverting the
source and re-running, not assumed.

The containment assertion is the one worth reading twice. It asks
where the panel *is* rather than whether a menu is clipped, because
CI's Chromium and WebKit both have the Popover API -- so the symptom is
invisible here and a spec asserting "not clipped" is green on the
broken build. `.planning/NOTES.md` states the mechanism.

The rest assert the entry rather than `aria-expanded`, which is the
shell's own bookkeeping and was right throughout the defect: what has
to be true is that one back press closes the queue and the *next* one
navigates.
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2026-08-20 22:14:42 -04:00
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import { test, expect } from '../support/fixtures.js';
/**
* #55 — the queue is a *place* while it covers the content, and a
* *control* while it sits beside it.
*
* #24 already made the pixels right: measured at the reference device's
* 424×439, the overlaid panel is 424×318, which is `.main-panel`'s rect
* exactly. What was missing was the navigation model, and the defect was
* measurable in one line — opening the queue on Artists and pressing
* back moved the page *underneath* to Albums and left the queue up. A
* back press that changes something the user cannot see, and costs them
* their place, is the whole of "it does not flow".
*
* **These assert the entry, not the attribute.** The temptation is to
* check `#queue-button[aria-expanded]` and stop, which is the shell's
* own bookkeeping and was right throughout the bug: what has to be true
* is that *one* back press closes the queue and the *next* one
* navigates. Asserting only the first would pass on a build that
* orphans the entry, which is the defect moved one press later — the
* same trap `back-navigation.spec.ts` documents about `data-active-view`
* and `layout-overflow.spec.ts` set for #69.
*
* **Three of these nine fail on the build before #55**, and the other
* six cannot, which is worth knowing before trusting them: "the entry
* is not orphaned" and "the column is not in the stack" are both
* vacuously true of a build that pushes no entry at all, and the
* containment assertion pins the mount that was *not* taken. They guard
* the next change rather than reproducing this one — the three that
* reproduce it are the two back-press tests and the touch target.
*/
type Page = import('@playwright/test').Page;
/** The reference device's real viewport, not a resized desktop. */
const DEVICE = { width: 424, height: 439 };
/** Wide enough that the queue is a column: 1280 200 320 ≥ 480. */
const DESKTOP = { width: 1280, height: 800 };
const activeView = (page: Page) => page.getByTestId('main-content');
const queue = (page: Page) => page.locator('#queue-panel');
const toggle = (page: Page) => page.locator('#queue-button');
async function expectQueue(page: Page, open: boolean): Promise<void> {
await expect(toggle(page)).toHaveAttribute(
'aria-expanded',
String(open),
);
}
test.describe('the queue is a screen where it covers the content', () => {
test.beforeEach(async ({ app }) => {
await app.setViewportSize(DEVICE);
await app.getByTestId('tab-albums').click();
await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
});
test('back closes the queue and leaves the page where it was', async ({
app,
}) => {
await expect(queue(app)).toHaveAttribute('overlay', '');
await toggle(app).click();
await expectQueue(app, true);
await app.goBack();
await expectQueue(app, false);
// The page underneath is untouched. Before #55 this was the
// *previous* view, because the queue was not in the stack at all
// and back spent an entry navigating something nobody could see.
await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
});
test('costs exactly one entry, so the next press navigates', async ({
app,
}) => {
await toggle(app).click();
await expectQueue(app, true);
await app.goBack();
await expectQueue(app, false);
await app.goBack();
// Whatever the launch page is, it is not Albums — the point is that
// this press moved the app rather than being swallowed by a queue
// that had already closed.
await expect(activeView(app)).not.toHaveAttribute(
'data-active-view',
'albums',
);
});
/**
* Every route out unwinds the entry, and they do it through the
* panel's own `open` attribute rather than each knowing about
* history — which is why a fourth route added later gets this free.
*
* The failure this pins is silent: close by button, and if the entry
* is orphaned the app looks correct until the next back press does
* nothing at all. It is a guard rather than a reproduction — a build
* with no entry to orphan passes it — and it is paired with the two
* above, which do reproduce.
*/
for (const [name, dismiss] of [
[
'the close button',
async (app: Page) => {
await app.getByRole('button', { name: 'Close queue' }).click();
},
],
[
'Escape',
async (app: Page) => {
await app.keyboard.press('Escape');
},
],
[
'the toggle it was opened from',
async (app: Page) => {
await toggle(app).click();
},
],
] as Array<[string, (app: Page) => Promise<void>]>) {
test(`${name} leaves no entry behind`, async ({ app }) => {
await toggle(app).click();
await expectQueue(app, true);
await dismiss(app);
await expectQueue(app, false);
await app.goBack();
await expect(activeView(app)).not.toHaveAttribute(
'data-active-view',
'albums',
);
});
}
/**
* A detail view leaves the destination it was opened from lit
* (`active-view-store`, #72), and the queue inherits that — it is
* published with `isPrimary: false`, so `isActive('albums')` is still
* true underneath it.
*
* `aria-current` rather than a class, for the reason
* `back-navigation.spec.ts` gives: the class was right throughout the
* bug that rule exists for.
*/
test('leaves the tab it was opened from highlighted', async ({ app }) => {
await expect(
app.getByRole('button', { name: 'Albums', exact: true }),
).toHaveAttribute('aria-current', 'page');
await toggle(app).click();
await expectQueue(app, true);
await expect(
app.getByRole('button', { name: 'Albums', exact: true }),
).toHaveAttribute('aria-current', 'page');
});
/**
* With the panel spanning the whole width the scrim has no uncovered
* pixels, so the close button is the only pointer route out of a
* full-screen surface. Measured at 424×439 before #55: **25×21px**.
*/
test('offers a way out a thumb can hit', async ({ app }) => {
await toggle(app).click();
const box = await app
.getByRole('button', { name: 'Close queue' })
.boundingBox();
expect(box).not.toBeNull();
expect(box!.width).toBeGreaterThanOrEqual(44);
expect(box!.height).toBeGreaterThanOrEqual(44);
});
});
/**
* **The mechanism, because no tier here can see the consequence.**
*
* #55's Direction asked for a `DETAIL_LOADERS` mount, which would put
* the panel inside `.main-panel > *`. That box is paint-contained under
* a `.main-panel` that is too, and `contain: paint` makes an element a
* containing block for fixed descendants *and clips them* — which is
* what a `wa-popup` falls back to on the reference device's Chrome 113,
* where the Popover API does not exist (#60, `.planning/NOTES.md`).
* `queue-panel` has a context menu, so that mount would have broken a
* working menu on the one device this issue is about.
*
* CI's Chromium and WebKit both *have* the Popover API, so the menu is
* top-layered and correct here either way: a spec asserting "the menu is
* not clipped" is green on the broken build. What a browser can answer
* honestly is where the element is, so that is what this asks.
*/
test('the panel stays out of the paint-contained region', async ({ app }) => {
await app.setViewportSize(DEVICE);
// Open, because that is the only state in which a menu can be opened
// from it — and because the host drops `paint` from its own
// containment deliberately in overlay mode, so a closed panel answers
// a different question.
await toggle(app).click();
await expectQueue(app, true);
const ancestry = await app.evaluate(() => {
const chain: Array<{ tag: string; contain: string }> = [];
for (
let el = document.getElementById('queue-panel');
el && el !== document.documentElement;
el = el.parentElement
) {
chain.push({
tag: el.tagName.toLowerCase(),
contain: getComputedStyle(el).contain,
});
}
return chain;
});
expect(ancestry.length).toBeGreaterThan(1);
expect(ancestry.some((a) => a.tag === 'main')).toBe(false);
for (const { tag, contain } of ancestry) {
expect(
`${tag}: ${contain}`,
'a paint-contained ancestor clips a fixed-positioned popup on Chrome 113',
).not.toMatch(/paint|content|strict/);
}
});
/**
* The column is not a place. Somebody docked it; back must not undock
* it, and navigating to another view must not take it away.
*
* This is the half a viewport breakpoint would get wrong: the mode is
* computed from the panel's own drag-resizable width, so the queue
* becomes a screen exactly when it stops being affordable as a column.
*/
test.describe('a docked queue is not in the back stack', () => {
test.beforeEach(async ({ app }) => {
await app.setViewportSize(DESKTOP);
});
test('survives a navigation, and back navigates the page', async ({
app,
}) => {
await app.getByTestId('nav-albums').click();
await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
await toggle(app).click();
await expectQueue(app, true);
await expect(queue(app)).not.toHaveAttribute('overlay', '');
await app.getByTestId('nav-artists').click();
await expect(activeView(app)).toHaveAttribute('data-active-view', 'artists');
await expectQueue(app, true);
await app.goBack();
await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
await expectQueue(app, true);
});
});