From 9b49a11710dfb9ded1cf3297696c32ffc64bf7e8 Mon Sep 17 00:00:00 2001 From: Adam Soltys Date: Sat, 26 Sep 2026 07:31:09 -0700 Subject: Feed: only the rows near the viewport are in the DOM, however far you scroll. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A long scroll left hundreds of rows mounted, and every repaint (a zap count, a profile landing, the thirty-second sync) rebuilt and diffed all of them — the slowdown deep in the feed. Rows beyond two and a half screens either side of the viewport are now replaced by a spacer at their measured height, so the page keeps its length (scrollbar, Back, arrival anchoring behave as before) while a repaint touches a few dozen rows. After svelte-virtual-list: measure after paint, estimate unmeasured rows at the running average, hold the reader's row still when a measurement corrects an estimate. Applies to the profile notes list too. Tests: feed-window-dom (120 posts, 27,800px page, 12–24 rows mounted, anchor held, spacers both sides); feed-live looks at the top after scrolling up; the moderation test's stub relay no longer lets real posts in. Co-Authored-By: Claude Fable 5.1 --- tools/feed-window-dom-test.js | 127 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 tools/feed-window-dom-test.js (limited to 'tools/feed-window-dom-test.js') diff --git a/tools/feed-window-dom-test.js b/tools/feed-window-dom-test.js new file mode 100644 index 0000000..d7a2f8c --- /dev/null +++ b/tools/feed-window-dom-test.js @@ -0,0 +1,127 @@ +// Windowing: however far you scroll, only the rows near the viewport are in +// the DOM — a spacer stands in for the rest at their measured height, so the +// page keeps its length, the row under your eyes never moves when the window +// shifts, and scrolling back up brings the top posts back. +// Run: bun tools/feed-window-dom-test.js +import puppeteer from 'puppeteer-core'; +import { cacheKeyFor } from '../src/wallet.js'; +import { generateSecretKey, getPublicKey, finalizeEvent } from 'nostr-tools/pure'; +import { buildHtml } from '../build.js'; +const sleep = (ms) => new Promise((r) => setTimeout(r, ms)); +let ok = true; +const check = (n, c, d = '') => { console.log(` ${c ? '✓' : '✗'} ${n}${d ? ' — ' + d : ''}`); if (!c) ok = false; }; +const SK = generateSecretKey(); +const AUTHOR = getPublicKey(SK); +const now = Math.floor(Date.now() / 1000); +// 120 cached posts of wildly different heights +const seeded = Array.from({ length: 120 }, (_, i) => finalizeEvent({ + kind: 1, created_at: now - 100 - i * 60, tags: [], + content: 'post number ' + (i + 1) + ' ' + (i % 3 === 0 ? 'short' : i % 3 === 1 ? 'a medium length post about nothing in particular, '.repeat(3) : 'a long one. '.repeat(30)), +}, SK)); + +const html = await buildHtml({ minify: true, pwa: false }); +const server = Bun.serve({ port: 5305, fetch: (req) => { + const path = new URL(req.url).pathname; + if (path.startsWith('/punks')) return new Response(Bun.file('dist' + path)); + return new Response(html, { headers: { 'content-type': 'text/html' } }); +} }); +const browser = await puppeteer.launch({ executablePath: '/usr/bin/google-chrome', headless: 'new', args: ['--no-sandbox'] }); +const page = await browser.newPage(); +// the stub relay holds every post: a kind-1 request is answered from it +// (honouring until/limit), everything else gets a bare EOSE +await page.evaluateOnNewDocument((all) => { + const Real = window.WebSocket; + window.WebSocket = function (...a) { + const ws = new Real(...a); + const send = ws.send.bind(ws); + ws.send = (data) => { + try { + const m = JSON.parse(data); + if (m[0] === 'REQ') { + const f = m[2] || {}; + const evs = (f.kinds || []).includes(1) && !f['#e'] && !f.ids + ? all.filter((e) => (!f.until || e.created_at <= f.until) && (!f.since || e.created_at >= f.since)).slice(0, f.limit || 100) : []; + setTimeout(() => { + for (const e of evs) ws.dispatchEvent(new MessageEvent('message', { data: JSON.stringify(['EVENT', m[1], e]) })); + ws.dispatchEvent(new MessageEvent('message', { data: JSON.stringify(['EOSE', m[1]]) })); + }, 0); + return; + } + if (m[0] === 'EVENT') return; + } catch {} + return send(data); + }; + return ws; + }; + window.WebSocket.prototype = Real.prototype; Object.assign(window.WebSocket, Real); +}, seeded); +const errs = []; +page.on('pageerror', (e) => errs.push(String(e))); +const click = (t) => page.evaluate((x) => { const e = [...document.querySelectorAll('button')].find((n) => n.textContent.trim().toLowerCase().includes(x)); if (e) { e.click(); return true; } return false; }, t); +const waitText = async (x, ms = 25000) => { for (let i = 0; i < ms / 250; i++) { if ((await page.evaluate(() => document.body.innerText)).toLowerCase().includes(x)) return true; await sleep(250); } return false; }; +const dom = () => page.evaluate(() => ({ + rows: document.querySelectorAll('.notes-feed > .row[data-key]').length, + top: document.querySelector('.notes-feed > [data-key="win-top"]')?.offsetHeight || 0, + bottom: document.querySelector('.notes-feed > [data-key="win-bottom"]')?.offsetHeight || 0, + height: document.documentElement.scrollHeight, y: window.scrollY, + first: document.querySelector('.notes-feed > .row[data-key]')?.innerText.match(/post number \d+/)?.[0], +})); +const anchor = () => page.evaluate(() => { + const r = [...document.querySelectorAll('.notes-feed > .row[data-key]')].find((n) => { const b = n.getBoundingClientRect(); return b.bottom > 0 && b.top < innerHeight; }); + return r ? { id: r.dataset.key, top: Math.round(r.getBoundingClientRect().top) } : null; +}); + +try { + await page.setViewport({ width: 390, height: 844 }); + await page.goto('http://localhost:5305/', { waitUntil: 'domcontentloaded' }); + await page.evaluate(() => localStorage.setItem('btc-wallet-network', 'regtest')); + await page.reload({ waitUntil: 'domcontentloaded' }); await sleep(400); + await click('create a new wallet'); await sleep(600); + await page.waitForSelector('.words .w .t'); + const mn = (await page.$$eval('.words .w .t', (l) => l.map((e) => e.textContent.trim()))).join(' '); + await click('skip verification'); + await waitText('receive', 20000); + const base = cacheKeyFor(mn + '\n'); + await page.evaluate(([k, pk, ns]) => { + localStorage.setItem(k + ':follows', JSON.stringify({ tags: [['p', pk]], c: '', at: Math.floor(Date.now() / 1000) })); + localStorage.setItem(k + ':feedNotes', JSON.stringify(ns)); + localStorage.setItem(k + ':profiles', JSON.stringify({ [pk]: { name: 'Prolific Poster', t: Date.now() } })); + }, [base, AUTHOR, seeded]); + await page.reload({ waitUntil: 'domcontentloaded' }); + await waitText('receive', 20000); + await page.evaluate(() => { const b = [...document.querySelectorAll('button')].find((e) => /message/i.test(e.getAttribute('aria-label') || '')); if (b) b.click(); }); await sleep(800); + await page.evaluate(() => { const e = [...document.querySelectorAll('.item')].find((n) => (n.querySelector('.chat-name') || {}).textContent === 'Feed'); if (e) e.click(); }); + await sleep(2500); + console.log('\n[a long scroll]'); + check('the feed opens on its first posts', (await dom()).first === 'post number 1', JSON.stringify(await dom())); + // page to the bottom, again and again + let d = null; + for (let i = 0; i < 14; i++) { + await page.evaluate(() => window.scrollTo(0, document.documentElement.scrollHeight)); + await sleep(700); + d = await dom(); + } + check('many pages in, the page is long', d.height > 6000, d.height + 'px'); + check('...but only a window of rows is mounted', d.rows > 0 && d.rows <= 60, d.rows + ' rows'); + check('...with a spacer standing in for the rows above', d.top > 1000, d.top + 'px'); + + console.log('\n[the row under your eyes stays put]'); + await page.evaluate(() => window.scrollTo(0, Math.round(document.documentElement.scrollHeight * 0.5))); await sleep(600); + const a1 = await anchor(); + // the window moves as you read; a beat later, nothing under the eyes has shifted + await page.evaluate(() => window.scrollBy(0, 300)); await sleep(400); + await page.evaluate(() => window.scrollBy(0, -300)); await sleep(600); + const a2 = await anchor(); + check('scrolling around and back leaves the same row at the same place', !!a1 && !!a2 && a1.id === a2.id && Math.abs(a1.top - a2.top) <= 2, JSON.stringify({ a1, a2 })); + const mid = await dom(); + check('mid-feed, spacers stand in above and below', mid.top > 500 && mid.bottom > 500 && mid.rows <= 60, JSON.stringify(mid)); + + console.log('\n[back to the top]'); + await page.evaluate(() => window.scrollTo(0, 0)); await sleep(800); + const t = await dom(); + check('the first posts are back in the DOM', t.first === 'post number 1' && t.top === 0, JSON.stringify(t)); + check('...and the rows below are held by a spacer', t.bottom > 1000 && t.rows <= 60, JSON.stringify(t)); + check('no page errors', errs.length === 0, errs.slice(0, 2).join(' | ')); +} finally { await browser.close(); server.stop(true); } +console.log(ok ? '\n✅ the feed stays light however far you scroll' : '\n❌ failed'); +process.exit(ok ? 0 : 1); -- cgit v1.2.3