yonlu
620151aa41
All four collections were fetched at DOMContentLoaded and refetched on every invalidation, whichever view was showing. On a 26 138-track library the track list was 20.5 MB of that, and encoding it cost the backend ~170 MB of transient allocation — paid by someone looking at Home, which draws none of it. - The store warms only albums, artists and genres, on idle after first paint: 1.6 MB together, and what made those views instant. - A nav item prefetches on hover and on keyboard focus, which is the ~100 ms before the click that a cold open would otherwise wait. - An invalidation refetches what something had loaded, and nothing else — a scan no longer loads the track list of a library whose Tracks view nobody has opened. - `index.html`'s first-paint `<track-list>` is `view-hidden`, and `index.ts` no longer activates it: it is markup, not a decision about which view the launch lands on, and activating it was what fetched the whole list for a landing on Home. The track list itself loads on view activation, which the shell drives. Measured on 50 000 tracks: backend RSS at rest 543 → 296 MB, peak 571 → 296 MB, Go heap held 361 → 125 MB, JS heap 31.8 → 18 MB, binding bytes at rest 35.9 → 12.1 MB, heap after a browse 36.5 → 22.7 MB. Tracks first open 26 ms; slowest view open 57 ms. Closes #280
59 lines
2.1 KiB
TypeScript
59 lines
2.1 KiB
TypeScript
/**
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* #280: launching the app must not load the track list.
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*
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* Every collection used to be fetched at `DOMContentLoaded` and
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* refetched on every invalidation, whichever view was showing. On a
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* 26 138-track library the track list was 20.5 MB of that, and encoding
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* it cost the backend ~170 MB of transient allocation — for someone
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* looking at Home, which draws none of it. Measured on 50 000 tracks:
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* 543 MB of backend RSS at rest before, 296 MB after.
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*
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* The negative assertion is the point, and it needs its complement: "no
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* `GetTrackTable`" also holds on a build that fetches nothing at all,
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* so the same spec opens Tracks and watches it arrive.
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*/
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import { test, expect, bindingCalls, navigateTo } from '../support/fixtures.js';
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const TRACKS = 'library.Library.GetTrackTable';
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/** The seed's default page, which is what a launch lands on. */
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const LANDING_VIEW = 'home';
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test('launching on Home does not load the track list', async ({ app }) => {
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// Past the store's idle warm-up: "nothing was fetched" has to mean
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// nothing, not "nothing has happened yet".
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await app.waitForTimeout(3_500);
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const calls = await bindingCalls(app);
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expect(calls, 'the warm-up for the small collections ran').toContain(
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'library.Library.GetAlbums',
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);
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expect(calls, `the track list was fetched at launch (${LANDING_VIEW})`).not.toContain(
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TRACKS,
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);
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});
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test('opening Tracks loads it, and only then', async ({ app }) => {
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await app.waitForTimeout(1_000);
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expect(await bindingCalls(app)).not.toContain(TRACKS);
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await navigateTo(app, 'tracks');
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await expect(app.getByTestId('track-row').first()).toBeVisible();
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expect(await bindingCalls(app)).toContain(TRACKS);
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});
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test('a hover on the nav item starts the load before the click', async ({ app }) => {
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await app.waitForTimeout(1_000);
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const nav = app.getByTestId('nav-tracks');
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// The pointer entering the item is the whole mechanism; nothing is
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// clicked, so the data must arrive because of the hover alone.
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await nav.hover();
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await expect
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.poll(async () => (await bindingCalls(app)).includes(TRACKS))
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.toBe(true);
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});
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