perf: enforce journey budgets and reference traces

scripts/check-bundle-budgets.mjs

@@ -0,0 +1,80 @@
+#!/usr/bin/env node
+import { brotliCompressSync, constants as zlibConstants } from 'node:zlib';
+import { readFile, readdir, stat } from 'node:fs/promises';
+import { relative, resolve, sep } from 'node:path';
+import { classifyArtifact, evaluateBudgetTotals, PERFORMANCE_BUDGETS } from './lib/bundle-budgets.mjs';
+
+const root = resolve(process.argv[2] ?? 'dist');
+if (!(await stat(root)).isDirectory()) throw new Error('Bundle budget target must be a directory.');
+
+const listFiles = async (directory) => {
+  const files = [];
+  for (const entry of await readdir(directory, { withFileTypes: true })) {
+    const path = resolve(directory, entry.name);
+    if (entry.isSymbolicLink()) throw new Error('Bundle budget input cannot contain symbolic links.');
+    if (entry.isDirectory()) files.push(...await listFiles(path));
+    else if (entry.isFile()) files.push(path);
+    else throw new Error('Bundle budget input contains an unsupported entry.');
+  }
+  return files;
+};
+
+const compressedSize = (path, bytes) => (/\.(?:avif|br|gif|jpe?g|mp4|png|webm|webp|woff2?)$/iu.test(path)
+  ? bytes.byteLength
+  : brotliCompressSync(bytes, {
+    params: { [zlibConstants.BROTLI_PARAM_QUALITY]: 11 },
+  }).byteLength);
+
+const records = [];
+for (const absolute of await listFiles(root)) {
+  const path = relative(root, absolute).split(sep).join('/');
+  const bytes = await readFile(absolute);
+  const source = /\.(?:css|html|js|json|txt|xml)$/u.test(path) ? bytes.toString('utf8') : '';
+  const bucket = classifyArtifact(path, source);
+  records.push({ path, bucket, bytes: bytes.byteLength, transferBytes: compressedSize(path, bytes) });
+}
+
+const sum = (bucket) => records.filter((record) => record.bucket === bucket).reduce((total, record) => total + record.transferBytes, 0);
+const totals = {
+  initialHtmlCriticalCss: sum('initial-html') + sum('critical-css'),
+  initialApplicationJs: sum('initial-application-js'),
+  heroPoster: sum('hero-poster'),
+  initialFonts: sum('initial-fonts'),
+  firstLiveScene: sum('first-live-scene'),
+  deferredProjectVisuals: sum('project-still') + sum('chart'),
+  deferredNonVideo: sum('first-live-scene') + sum('project-still') + sum('chart'),
+};
+
+for (const record of records.filter((item) => item.bucket === 'project-video')) {
+  if (record.transferBytes > PERFORMANCE_BUDGETS.projectVideo) {
+    throw new Error(`Project video exceeds its transfer budget: ${record.path}`);
+  }
+}
+for (const record of records.filter((item) => item.bucket === 'project-still')) {
+  if (record.transferBytes > PERFORMANCE_BUDGETS.projectStill) {
+    throw new Error(`Project still exceeds its transfer budget: ${record.path}`);
+  }
+}
+for (const record of records.filter((item) => item.bucket === 'chart')) {
+  if (record.transferBytes > PERFORMANCE_BUDGETS.chart) {
+    throw new Error(`Chart exceeds its transfer budget: ${record.path}`);
+  }
+}
+
+const entry = records.find((record) => record.bucket === 'initial-application-js');
+const scene = records.find((record) => record.bucket === 'first-live-scene');
+if (entry === undefined || scene === undefined) throw new Error('Both initial application and deferred live-scene chunks are required.');
+const entrySource = await readFile(resolve(root, entry.path), 'utf8');
+if (!/import\([^)]*environment-/u.test(entrySource)) throw new Error('The live scene is not separated behind a dynamic import.');
+if (/WebGLRenderer|WebGLProgram|ShaderMaterial/u.test(entrySource)) throw new Error('Three.js/live-scene code leaked into the reduced-motion initial chunk.');
+
+const result = evaluateBudgetTotals(totals);
+const report = {
+  schema: 'portfolio-bundle-budget/v1',
+  compression: 'brotli-quality-11-or-raw-already-compressed',
+  totals,
+  records: records.sort((left, right) => left.path.localeCompare(right.path)),
+  violations: result.violations,
+};
+process.stdout.write(`${JSON.stringify(report, null, 2)}\n`);
+if (result.violations.length > 0) process.exitCode = 1;