1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617#!/usr/bin/env node
/**
* Benchmark harness: compares Next.js 16 (Turbopack) vs vinext (Vite 7/Rollup) vs vinext (Vite 8/Rolldown)
*
* Metrics:
* 1. Production build time (hyperfine)
* 2. Production bundle size (total JS+CSS, gzipped)
* 3. Dev server cold start (time to first successful HTTP 200)
* 4. SSR throughput & TTFB (autocannon against production server)
* 5. Memory usage (peak RSS during build and dev)
*
* Prerequisites: hyperfine, autocannon (npm i -g autocannon)
* Usage: node benchmarks/run.mjs [--runs N] [--dev-runs N] [--skip-build] [--skip-dev] [--skip-ssr] [--skip-rolldown]
*/
import { execSync, spawn } from "node:child_process";
import { existsSync, readdirSync, statSync, writeFileSync, mkdirSync, readFileSync } from "node:fs";
import { join, dirname } from "node:path";
import { fileURLToPath } from "node:url";
import { gzipSync } from "node:zlib";
const __dirname = dirname(fileURLToPath(import.meta.url));
const RESULTS_DIR = join(__dirname, "results");
mkdirSync(RESULTS_DIR, { recursive: true });
// Disable Next.js telemetry to avoid non-deterministic network latency in benchmarks.
process.env.NEXT_TELEMETRY_DISABLED = "1";
// ─── CLI args ──────────────────────────────────────────────────────────────────
const args = process.argv.slice(2);
const RUNS = parseInt(args.find((a) => a.startsWith("--runs="))?.split("=")[1] ?? "5", 10);
const DEV_RUNS = parseInt(args.find((a) => a.startsWith("--dev-runs="))?.split("=")[1] ?? "10", 10);
const SKIP_BUILD = args.includes("--skip-build");
const SKIP_DEV = args.includes("--skip-dev");
const SKIP_SSR = args.includes("--skip-ssr");
const SKIP_ROLLDOWN = args.includes("--skip-rolldown");
// ─── Helpers ───────────────────────────────────────────────────────────────────
function exec(cmd, opts = {}) {
console.log(` $ ${cmd}`);
return execSync(cmd, { encoding: "utf-8", stdio: "pipe", ...opts });
}
function getGitHash() {
try {
return execSync("git rev-parse --short HEAD", { encoding: "utf-8", cwd: join(__dirname, "..") }).trim();
} catch {
return "unknown";
}
}
/**
* Calculate total size of JS and CSS files in a directory (recursively).
* Returns { raw: bytes, gzip: bytes, files: number }
*/
function bundleSize(dir) {
let raw = 0;
let gzip = 0;
let files = 0;
function walk(d) {
if (!existsSync(d)) return;
for (const entry of readdirSync(d)) {
const full = join(d, entry);
const stat = statSync(full);
if (stat.isDirectory()) {
walk(full);
} else if (/\.(js|css|mjs)$/.test(entry)) {
const content = readFileSync(full);
raw += content.length;
gzip += gzipSync(content).length;
files++;
}
}
}
walk(dir);
return { raw, gzip, files };
}
/**
* Wait for a URL to return HTTP 200. Returns time in ms.
*/
async function waitForServer(url, timeoutMs = 60000) {
const start = performance.now();
const deadline = start + timeoutMs;
while (performance.now() < deadline) {
try {
const res = await fetch(url, { signal: AbortSignal.timeout(2000) });
if (res.ok) return performance.now() - start;
} catch {
// not ready yet
}
await new Promise((r) => setTimeout(r, 200));
}
throw new Error(`Server at ${url} did not respond within ${timeoutMs}ms`);
}
/**
* Sum RSS (in KB) for an entire process group.
* The process was spawned with detached:true so proc.pid is the PGID.
* On Linux, `pgrep -g` enumerates PIDs in the process group reliably.
* On macOS, `pgrep -g` matches by GID (not PGID), so instead we list all
* processes with `ps -axo pid=,pgid=,rss=` and sum RSS for rows whose PGID
* matches the leader PID.
*/
function getGroupRssKb(pid) {
try {
let out;
if (process.platform === "linux") {
const pidsRaw = execSync(`pgrep -g ${pid}`, { encoding: "utf-8" }).trim();
if (!pidsRaw) return 0;
const pidList = pidsRaw.split("\n").join(",");
out = execSync(`ps -o rss= -p ${pidList}`, { encoding: "utf-8" });
return out
.trim()
.split("\n")
.reduce((sum, line) => sum + (parseInt(line.trim(), 10) || 0), 0);
} else {
// macOS: enumerate all processes and sum RSS for those in our PGID
out = execSync(`ps -axo pid=,pgid=,rss=`, { encoding: "utf-8" });
const pgid = String(pid);
return out
.trim()
.split("\n")
.reduce((sum, line) => {
const parts = line.trim().split(/\s+/);
if (parts.length >= 3 && parts[1] === pgid) {
return sum + (parseInt(parts[2], 10) || 0);
}
return sum;
}, 0);
}
} catch {
return 0;
}
}
/**
* Start a process and measure cold start time + peak RSS.
* Returns { coldStartMs, peakRssKb, process }
*/
async function startAndMeasure(cmd, args, cwd, url) {
let peakRssKb = 0;
const proc = spawn(cmd, args, {
cwd,
stdio: ["pipe", "pipe", "pipe"],
detached: true, // Own process group so we can kill the tree safely
env: { ...process.env, PORT: new URL(url).port },
});
// Collect stderr/stdout for debugging
let output = "";
proc.stdout?.on("data", (d) => (output += d.toString()));
proc.stderr?.on("data", (d) => (output += d.toString()));
// Poll RSS every 200ms (sum across process group on Linux)
const rssInterval = setInterval(() => {
const rss = getGroupRssKb(proc.pid);
if (rss > peakRssKb) peakRssKb = rss;
}, 200);
try {
const coldStartMs = await waitForServer(url, 60000);
clearInterval(rssInterval);
// Final RSS
const rss = getGroupRssKb(proc.pid);
if (rss > peakRssKb) peakRssKb = rss;
return { coldStartMs, peakRssKb, process: proc, output };
} catch (err) {
clearInterval(rssInterval);
kill(proc);
console.error("Server output:", output);
throw err;
}
}
function kill(proc) {
if (!proc || proc.killed) return;
// The process was spawned with detached:true so it has its own process group.
// Kill the entire group with -PID (negative) which is safe because it won't
// include our own script.
try {
process.kill(-proc.pid, "SIGKILL");
} catch {}
}
// Fisher-Yates shuffle — used to randomize runner order and eliminate positional bias.
function shuffle(arr) {
const a = [...arr];
for (let i = a.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[a[i], a[j]] = [a[j], a[i]];
}
return a;
}
function formatBytes(b) {
if (b < 1024) return `${b} B`;
if (b < 1024 * 1024) return `${(b / 1024).toFixed(1)} KB`;
return `${(b / (1024 * 1024)).toFixed(2)} MB`;
}
function formatMs(ms) {
if (ms < 1000) return `${Math.round(ms)} ms`;
return `${(ms / 1000).toFixed(2)} s`;
}
// ─── Main ──────────────────────────────────────────────────────────────────────
async function main() {
const results = {
timestamp: new Date().toISOString(),
gitHash: getGitHash(),
buildRuns: RUNS,
devRuns: DEV_RUNS,
system: {
platform: process.platform,
arch: process.arch,
nodeVersion: process.version,
cpus: (await import("node:os")).cpus().length,
},
nextjs: {},
vinext: {},
vinextRolldown: {},
};
const nextjsDir = join(__dirname, "nextjs");
const vinextDir = join(__dirname, "vinext");
const vinextRolldownDir = join(__dirname, "vinext-rolldown");
const hasRolldown = !SKIP_ROLLDOWN && existsSync(join(vinextRolldownDir, "package.json"));
// Detect actual installed versions for reproducibility
try {
const njsPkg = JSON.parse(readFileSync(join(nextjsDir, "node_modules", "next", "package.json"), "utf-8"));
results.system.nextjsVersion = njsPkg.version;
} catch { /* deps not installed yet */ }
try {
const vitePkg = JSON.parse(readFileSync(join(vinextDir, "node_modules", "vite", "package.json"), "utf-8"));
results.system.viteVersion = vitePkg.version;
} catch { /* deps not installed yet */ }
if (hasRolldown) {
try {
const rdPkg = JSON.parse(readFileSync(join(vinextRolldownDir, "node_modules", "vite", "package.json"), "utf-8"));
results.system.viteRolldownVersion = rdPkg.version;
} catch { /* deps not installed yet */ }
}
// ─── 1. Production Build Time ──────────────────────────────────────────────
if (!SKIP_BUILD) {
console.log("\n=== Production Build Time ===\n");
// Clean previous builds
exec("rm -rf .next", { cwd: nextjsDir });
exec("rm -rf dist", { cwd: vinextDir });
if (hasRolldown) exec("rm -rf dist", { cwd: vinextRolldownDir });
// Ensure plugin is built
console.log(" Building vinext plugin...");
exec("./node_modules/.bin/tsc -p packages/vinext/tsconfig.json", { cwd: join(__dirname, "..") });
// Warmup run for all (not measured)
console.log(" Warmup: Next.js build...");
exec("./node_modules/.bin/next build --turbopack", { cwd: nextjsDir, timeout: 120000 });
exec("rm -rf .next", { cwd: nextjsDir });
console.log(" Warmup: vinext (Rollup) build...");
exec("./node_modules/.bin/vite build", { cwd: vinextDir, timeout: 120000 });
exec("rm -rf dist", { cwd: vinextDir });
if (hasRolldown) {
console.log(" Warmup: vinext (Rolldown) build...");
exec("./node_modules/.bin/vite build", { cwd: vinextRolldownDir, timeout: 120000 });
exec("rm -rf dist", { cwd: vinextRolldownDir });
}
// Measured runs with hyperfine (single invocation with --shuffle for fair ordering)
console.log(`\n Running ${RUNS} build iterations with hyperfine (randomized order)...\n`);
function parseHyperfineResult(r) {
return {
mean: r.mean * 1000,
stddev: r.stddev * 1000,
min: r.min * 1000,
max: r.max * 1000,
};
}
try {
// Build a single hyperfine command with all projects and --shuffle so
// runs are interleaved randomly, eliminating positional bias from
// warmed filesystem caches, CPU thermal state, or residual process state.
const cmds = [
`--command-name nextjs 'rm -rf ${nextjsDir}/.next && ./node_modules/.bin/next build --turbopack'`,
`--command-name vinext 'rm -rf ${vinextDir}/dist && ./node_modules/.bin/vite build --root ${vinextDir}'`,
];
if (hasRolldown) {
cmds.push(
`--command-name rolldown 'rm -rf ${vinextRolldownDir}/dist && ./node_modules/.bin/vite build --root ${vinextRolldownDir}'`
);
}
console.log(" Timing all builds (shuffled)...");
const hfJson = exec(
`hyperfine --runs ${RUNS} --shuffle ${cmds.join(" ")} --export-json /dev/stdout 2>/dev/null`,
{ cwd: __dirname, timeout: 600000 }
);
const hf = JSON.parse(hfJson);
// Map results by command name
for (const r of hf.results) {
if (r.command.includes("next build")) {
results.nextjs.buildTime = parseHyperfineResult(r);
} else if (r.command.includes(vinextDir)) {
results.vinext.buildTime = parseHyperfineResult(r);
} else if (hasRolldown && r.command.includes(vinextRolldownDir)) {
results.vinextRolldown.buildTime = parseHyperfineResult(r);
}
}
results.buildMethodology = "hyperfine --shuffle (randomized)";
} catch {
// Fallback: manual timing with randomized runner order to eliminate positional bias
console.log(" hyperfine failed, falling back to manual timing...");
const buildTimes = { nextjs: [], vinext: [], rolldown: [] };
const buildRunners = [
{
key: "nextjs",
run: () => {
exec("rm -rf .next", { cwd: nextjsDir });
const start = performance.now();
exec("./node_modules/.bin/next build --turbopack", { cwd: nextjsDir, timeout: 120000 });
buildTimes.nextjs.push(performance.now() - start);
},
},
{
key: "vinext",
run: () => {
exec("rm -rf dist", { cwd: vinextDir });
const start = performance.now();
exec("./node_modules/.bin/vite build", { cwd: vinextDir, timeout: 120000 });
buildTimes.vinext.push(performance.now() - start);
},
},
...(hasRolldown
? [{
key: "rolldown",
run: () => {
exec("rm -rf dist", { cwd: vinextRolldownDir });
const start = performance.now();
exec("./node_modules/.bin/vite build", { cwd: vinextRolldownDir, timeout: 120000 });
buildTimes.rolldown.push(performance.now() - start);
},
}]
: []),
];
const buildRunOrders = [];
for (let i = 0; i < RUNS; i++) {
const order = shuffle(buildRunners);
buildRunOrders.push(order.map((r) => r.key));
console.log(` Run ${i + 1}/${RUNS} (order: ${order.map((r) => r.key).join(" → ")})...`);
for (const runner of order) runner.run();
}
const avg = (arr) => arr.reduce((a, b) => a + b, 0) / arr.length;
const stddev = (arr) => {
if (arr.length < 2) return 0;
const m = avg(arr);
return Math.sqrt(arr.reduce((s, v) => s + (v - m) ** 2, 0) / (arr.length - 1));
};
results.nextjs.buildTime = {
mean: avg(buildTimes.nextjs),
stddev: stddev(buildTimes.nextjs),
min: Math.min(...buildTimes.nextjs),
max: Math.max(...buildTimes.nextjs),
};
results.vinext.buildTime = {
mean: avg(buildTimes.vinext),
stddev: stddev(buildTimes.vinext),
min: Math.min(...buildTimes.vinext),
max: Math.max(...buildTimes.vinext),
};
if (hasRolldown && buildTimes.rolldown.length) {
results.vinextRolldown.buildTime = {
mean: avg(buildTimes.rolldown),
stddev: stddev(buildTimes.rolldown),
min: Math.min(...buildTimes.rolldown),
max: Math.max(...buildTimes.rolldown),
};
}
results.buildMethodology = "manual timing (randomized)";
results.buildRunOrders = buildRunOrders;
}
// ─── 2. Bundle Size ────────────────────────────────────────────────────────
// Measures client-side JS/CSS/MJS files only. Both directories (.next/static
// and dist/client) contain only browser assets, not server bundles.
// TODO: If the benchmark app ever uses CSS Modules or global CSS imports,
// verify that both frameworks extract CSS to the measured directories.
// Currently the app uses inline styles so CSS extraction is not a factor.
console.log("\n=== Production Bundle Size ===\n");
// Rebuild both to get fresh output
exec("rm -rf .next", { cwd: nextjsDir });
exec("./node_modules/.bin/next build --turbopack", { cwd: nextjsDir, timeout: 120000 });
exec("rm -rf dist", { cwd: vinextDir });
exec("./node_modules/.bin/vite build", { cwd: vinextDir, timeout: 120000 });
// Next.js: client bundles are in .next/static
const njsSize = bundleSize(join(nextjsDir, ".next", "static"));
results.nextjs.bundleSize = njsSize;
console.log(` Next.js: ${njsSize.files} files, ${formatBytes(njsSize.raw)} raw, ${formatBytes(njsSize.gzip)} gzip`);
// vinext (Rollup): client bundles are in dist/client
const ncSize = bundleSize(join(vinextDir, "dist", "client"));
results.vinext.bundleSize = ncSize;
console.log(` vinext (Rollup): ${ncSize.files} files, ${formatBytes(ncSize.raw)} raw, ${formatBytes(ncSize.gzip)} gzip`);
// vinext (Rolldown): client bundles are in dist/client
if (hasRolldown) {
exec("rm -rf dist", { cwd: vinextRolldownDir });
exec("./node_modules/.bin/vite build", { cwd: vinextRolldownDir, timeout: 120000 });
const rdSize = bundleSize(join(vinextRolldownDir, "dist", "client"));
results.vinextRolldown.bundleSize = rdSize;
console.log(` vinext (Rolldown): ${rdSize.files} files, ${formatBytes(rdSize.raw)} raw, ${formatBytes(rdSize.gzip)} gzip`);
}
}
// ─── 3. Dev Server Cold Start ──────────────────────────────────────────────
if (!SKIP_DEV) {
console.log("\n=== Dev Server Cold Start ===\n");
const devResults = { nextjs: [], vinext: [], rolldown: [] };
// Define the runners; order is randomized each iteration to eliminate
// positional bias (first-after-kill penalties, OS cache warming, etc.)
const runners = [
{
key: "nextjs",
label: "Next.js",
run: async () => {
exec("rm -rf .next", { cwd: nextjsDir });
return startAndMeasure("./node_modules/.bin/next", ["dev", "--turbopack", "-p", "4100"], nextjsDir, "http://localhost:4100");
},
},
{
key: "vinext",
label: "vinext (Rollup)",
run: async () => {
exec("rm -rf node_modules/.vite", { cwd: vinextDir });
return startAndMeasure("./node_modules/.bin/vite", ["--port", "4101"], vinextDir, "http://localhost:4101");
},
},
...(hasRolldown
? [
{
key: "rolldown",
label: "vinext (Rolldown)",
run: async () => {
exec("rm -rf node_modules/.vite", { cwd: vinextRolldownDir });
return startAndMeasure("./node_modules/.bin/vite", ["--port", "4102"], vinextRolldownDir, "http://localhost:4102");
},
},
]
: []),
];
const runOrders = [];
for (let i = 0; i < DEV_RUNS; i++) {
const order = shuffle(runners);
const orderLabels = order.map((r) => r.label);
runOrders.push(orderLabels);
console.log(` Run ${i + 1}/${DEV_RUNS} (order: ${orderLabels.join(" → ")})...`);
for (const runner of order) {
console.log(` Starting ${runner.label} dev server...`);
const result = await runner.run();
devResults[runner.key].push({ coldStartMs: result.coldStartMs, peakRssKb: result.peakRssKb });
console.log(` ${runner.label}: ${formatMs(result.coldStartMs)}, ${Math.round(result.peakRssKb / 1024)} MB RSS`);
kill(result.process);
await new Promise((r) => setTimeout(r, 2000)); // cooldown
}
}
const avg = (arr) => arr.reduce((a, b) => a + b, 0) / arr.length;
results.nextjs.devColdStart = {
meanMs: avg(devResults.nextjs.map((r) => r.coldStartMs)),
meanRssKb: avg(devResults.nextjs.map((r) => r.peakRssKb)),
runs: devResults.nextjs,
};
results.vinext.devColdStart = {
meanMs: avg(devResults.vinext.map((r) => r.coldStartMs)),
meanRssKb: avg(devResults.vinext.map((r) => r.peakRssKb)),
runs: devResults.vinext,
};
if (hasRolldown && devResults.rolldown.length) {
results.vinextRolldown.devColdStart = {
meanMs: avg(devResults.rolldown.map((r) => r.coldStartMs)),
meanRssKb: avg(devResults.rolldown.map((r) => r.peakRssKb)),
runs: devResults.rolldown,
};
}
results.devRunOrders = runOrders;
}
// ─── 4. SSR Throughput & TTFB ──────────────────────────────────────────────
// TODO: Requires wiring up vinext production server (startProdServer)
// to serve dynamic SSR pages, not just static preview. Skipped for now.
if (!SKIP_SSR) {
console.log("\n=== SSR Throughput & TTFB ===\n");
console.log(" Skipped — vinext production server not yet wired for benchmark app.");
console.log(" Next.js `next start` does SSR; vinext `vite preview` only serves static.");
console.log(" This will be added once the prod server integration is complete.\n");
}
// ─── Output Results ────────────────────────────────────────────────────────
console.log("\n=== Results ===\n");
// Save JSON
const jsonFile = join(RESULTS_DIR, `bench-${results.gitHash}-${Date.now()}.json`);
writeFileSync(jsonFile, JSON.stringify(results, null, 2));
console.log(` JSON: ${jsonFile}\n`);
// Generate markdown summary
let md = `# Benchmark Results\n\n`;
md += `- **Date**: ${results.timestamp}\n`;
md += `- **Git**: ${results.gitHash}\n`;
md += `- **Node**: ${results.system.nodeVersion}\n`;
md += `- **CPUs**: ${results.system.cpus}\n`;
md += `- **Build runs**: ${results.buildRuns}\n`;
md += `- **Dev cold start runs**: ${results.devRuns}\n`;
if (results.system.nextjsVersion) md += `- **Next.js**: ${results.system.nextjsVersion}\n`;
if (results.system.viteVersion) md += `- **Vite (Rollup)**: ${results.system.viteVersion}\n`;
if (results.system.viteRolldownVersion) md += `- **Vite (Rolldown)**: ${results.system.viteRolldownVersion}\n`;
md += "\n";
md += `> **Note:** TypeScript type checking is disabled for the Next.js build (\`typescript.ignoreBuildErrors: true\`) so that build timings measure bundler/compilation speed only. Vite does not type-check during build.\n\n`;
md += `> **Methodology:** Build and dev cold start runs are executed in randomized order to eliminate positional bias from filesystem caches, CPU thermal state, and residual process state.\n\n`;
const hasRolldownResults = results.vinextRolldown && Object.keys(results.vinextRolldown).length > 0;
// Format a speed ratio comparison: "2.1x faster" or "1.3x slower"
function fmtSpeedup(baseline, value) {
if (!baseline || !value) return "N/A";
const ratio = baseline / value;
if (ratio > 1) return `**${ratio.toFixed(1)}x faster**`;
if (ratio < 1) return `**${(1 / ratio).toFixed(1)}x slower**`;
return "same";
}
// Format a size reduction: "56% smaller" or "12% larger"
function fmtSizeReduction(baseline, value) {
if (!baseline || !value) return "N/A";
const pct = Math.round((1 - value / baseline) * 100);
if (pct > 0) return `**${pct}% smaller**`;
if (pct < 0) return `**${Math.abs(pct)}% larger**`;
return "same";
}
if (results.nextjs.buildTime && results.vinext.buildTime) {
md += `## Production Build Time\n\n`;
md += `| Framework | Mean | StdDev | Min | Max | vs Next.js |\n`;
md += `|-----------|------|--------|-----|-----|------------|\n`;
md += `| Next.js 16 (Turbopack) | ${formatMs(results.nextjs.buildTime.mean)} | ±${formatMs(results.nextjs.buildTime.stddev)} | ${formatMs(results.nextjs.buildTime.min)} | ${formatMs(results.nextjs.buildTime.max)} | baseline |\n`;
md += `| vinext (Vite 7 / Rollup) | ${formatMs(results.vinext.buildTime.mean)} | ±${formatMs(results.vinext.buildTime.stddev)} | ${formatMs(results.vinext.buildTime.min)} | ${formatMs(results.vinext.buildTime.max)} | ${fmtSpeedup(results.nextjs.buildTime.mean, results.vinext.buildTime.mean)} |\n`;
if (hasRolldownResults && results.vinextRolldown.buildTime) {
md += `| vinext (Vite 8 / Rolldown) | ${formatMs(results.vinextRolldown.buildTime.mean)} | ±${formatMs(results.vinextRolldown.buildTime.stddev)} | ${formatMs(results.vinextRolldown.buildTime.min)} | ${formatMs(results.vinextRolldown.buildTime.max)} | ${fmtSpeedup(results.nextjs.buildTime.mean, results.vinextRolldown.buildTime.mean)} |\n`;
}
md += "\n";
}
if (results.nextjs.bundleSize && results.vinext.bundleSize) {
md += `## Production Bundle Size (Client)\n\n`;
md += `| Framework | Files | Raw | Gzipped | vs Next.js (gzip) |\n`;
md += `|-----------|-------|-----|----------|--------------------|\n`;
md += `| Next.js 16 | ${results.nextjs.bundleSize.files} | ${formatBytes(results.nextjs.bundleSize.raw)} | ${formatBytes(results.nextjs.bundleSize.gzip)} | baseline |\n`;
md += `| vinext (Rollup) | ${results.vinext.bundleSize.files} | ${formatBytes(results.vinext.bundleSize.raw)} | ${formatBytes(results.vinext.bundleSize.gzip)} | ${fmtSizeReduction(results.nextjs.bundleSize.gzip, results.vinext.bundleSize.gzip)} |\n`;
if (hasRolldownResults && results.vinextRolldown.bundleSize) {
md += `| vinext (Rolldown) | ${results.vinextRolldown.bundleSize.files} | ${formatBytes(results.vinextRolldown.bundleSize.raw)} | ${formatBytes(results.vinextRolldown.bundleSize.gzip)} | ${fmtSizeReduction(results.nextjs.bundleSize.gzip, results.vinextRolldown.bundleSize.gzip)} |\n`;
}
md += "\n";
}
if (results.nextjs.devColdStart && results.vinext.devColdStart) {
md += `## Dev Server Cold Start\n\n`;
md += `| Framework | Mean Cold Start | Mean Peak RSS | vs Next.js |\n`;
md += `|-----------|----------------|----------------|------------|\n`;
md += `| Next.js 16 (Turbopack) | ${formatMs(results.nextjs.devColdStart.meanMs)} | ${Math.round(results.nextjs.devColdStart.meanRssKb / 1024)} MB | baseline |\n`;
md += `| vinext (Vite 7 / Rollup) | ${formatMs(results.vinext.devColdStart.meanMs)} | ${Math.round(results.vinext.devColdStart.meanRssKb / 1024)} MB | ${fmtSpeedup(results.nextjs.devColdStart.meanMs, results.vinext.devColdStart.meanMs)} |\n`;
if (hasRolldownResults && results.vinextRolldown.devColdStart) {
md += `| vinext (Vite 8 / Rolldown) | ${formatMs(results.vinextRolldown.devColdStart.meanMs)} | ${Math.round(results.vinextRolldown.devColdStart.meanRssKb / 1024)} MB | ${fmtSpeedup(results.nextjs.devColdStart.meanMs, results.vinextRolldown.devColdStart.meanMs)} |\n`;
}
md += "\n";
}
// SSR throughput section will be added once prod server is wired up
const mdFile = join(RESULTS_DIR, `bench-${results.gitHash}-${Date.now()}.md`);
writeFileSync(mdFile, md);
console.log(` Markdown: ${mdFile}\n`);
console.log(md);
}
main().catch((err) => {
console.error("Benchmark failed:", err);
process.exit(1);
});