Files
EpicNext-Cms/docs/performance-budgets.md
T
openhands 11ad6d4376
Gitea Actions Runner Test / test-job (push) Successful in 1s
CI / check (push) Successful in 31s
CI / tests-integration (push) Successful in 1m41s
CI / tests-unit (push) Successful in 1m44s
CI / tests-ui (push) Successful in 2m31s
CI / preflight (push) Skipped
CI / deploy (push) Failing after 2m25s
fix(ci): measure route bundles from webpack manifests
The performance report measured nothing. It only read `entryJSFiles` from
each route's client-reference manifest, a field Turbopack emits and webpack
does not. When the build moved to webpack (3d828a61) every route fell
through to the "unavailable" branch, and because the report is informational
and exits 0 on an unavailable metric, nothing failed and the budgets quietly
stopped being enforced.

Derive the envelope from clientModules[*].chunks when entryJSFiles is
absent, which is the same source Next's own static-routes-info uses for
webpack builds. Webpack interleaves numeric chunk ids with file names in
those arrays, so ids are skipped by shape while a malformed chunk path still
throws — otherwise a broken manifest would quietly under-report a route.
entryJSFiles still wins when present, since it is per-segment and therefore
the tighter envelope, and the per-chunk origin label is shared rather than
the absolute node_modules path webpack records, which would otherwise bloat
report.json.

Six tests cover the webpack layout: id filtering, deduplication of a chunk
reached by several client modules, the origin label, the malformed-path
rejection, the no-chunks-at-all case, and entryJSFiles taking precedence.

Re-measured on the current build, all six routes are inside their budgets
again. Note /admin/studio/furni now sits at ~98% of its gzip limit, so one
more dependency on that route will trip it; docs/performance-budgets.md
records the webpack baseline numbers and how to recalibrate.

Verified: 3385 tests, typecheck and biome clean, and the report now emits
measured rows instead of six unavailable ones.
2026-10-05 20:49:53 +02:00

48 lines
5.5 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
# Informational route JavaScript budgets
Run after the existing production build; no second build or server is needed:
```sh
node scripts/performance-report.mjs --next-dir .next --config scripts/performance-budgets.json --output-dir build-reports
```
The command writes `report.json` and `report.md` and prints the Markdown report. An optional `PERFORMANCE_COMMIT_SHA` environment variable records the commit declared by the build caller; the script does not infer that an existing build matches the current checkout. JSON also records `BUILD_ID`, Node/zlib versions, manifest provenance, exact file paths, sizes and source entries.
## What is measured
For each configured App Router route, resolve its exact app path using `app-path-routes-manifest.json` and `server/app-paths-manifest.json`. Read its generated `page_client-reference-manifest.js` as a JSON assignment **without executing JavaScript**. Use its sibling `page/build-manifest.json`, falling back to the root build manifest only if that sibling is absent.
The **initial entry envelope** is the union of route bootstrap `rootMainFilesTree[appPath]` (or `rootMainFiles`) and every client chunk that route's client-reference manifest lists. This includes layout, page and boundary/loading entries.
The manifest exposes those chunks differently per bundler. Turbopack emits an explicit per-segment `entryJSFiles` map; webpack emits no such field and records chunks only per client module, as `clientModules[*].chunks`, in `[chunkId, fileName, chunkId, fileName, …]` order. The report reads `entryJSFiles` when present and otherwise derives the same envelope from `clientModules`, which is the source Next's own `static-routes-info` uses. Numeric chunk ids are skipped; a malformed chunk *path* still fails rather than being dropped, so a broken manifest cannot quietly under-report a route.
> The build runs webpack (`next build --webpack`), so the `clientModules` path is the live one. An earlier revision only read `entryJSFiles`, and after the switch to webpack every route reported `unavailable` while the command still exited 0 — the budgets were silently not being measured. When a bundler switch changes the manifest layout again, re-check this section rather than trusting a clean exit.
The definition follows the data exposed by the installed Next 16.3.8 build and the `getLinkAndScriptTags` / `getRequiredScripts` renderer helpers; it is deliberately a build-artifact envelope, not a browser network trace. Conditional rendering, redirects, streaming and browser caches can change actual requests.
- Raw bytes are filesystem byte lengths of unique JavaScript assets in that envelope.
- Gzip bytes are the **sum of independent gzip level 9 compressions** of those files using the recorded Node/zlib runtime. They are not gzip of concatenated source, nor observed CDN transfer sizes.
- Deployment query strings and `/_next/` prefixes are normalized before deduplication. Shared files count once per route; each route is measured independently, with no misleading cross-route total.
- Legacy `nomodule` polyfills are measured separately, outside the modern initial budget. CSS, source maps, images, external scripts, HTML/RSC payloads and async-only chunks absent from the manifest's chunk lists are excluded.
- This report makes no claims about execution cost, LCP, hydration time or real-user performance.
## Initial limits
The first limits are **baseline bytes × 1.15, rounded upward to the next 10 KiB (10,240 bytes)** independently for raw and gzip. They are provisional size alerts, not validated speed targets. Baseline: local production build `build-TfctsWXpff2fKS`, Next 16.3.4 **Turbopack**; its source commit was not inferred.
The production build now runs webpack, so the numbers it reports are not directly comparable to the baseline below. Re-measured on the current webpack build the routes land at `/me` 786138/247738, `/news` 781601/245672, `/events` 782011/245923, `/search` 783262/246578, `/admin/catalog` 1172089/370843, `/admin/studio/furni` 1374128/440546 (raw/gzip). All remain inside the limits below, but `/admin/studio/furni` sits at ~98% of its gzip limit, so the next dependency added to that route will trip it. Recalibrate the table and `scripts/performance-budgets.json` together if the intent is to reset the baseline on webpack.
| Route | Baseline raw bytes | Baseline gzip bytes | Raw limit | Gzip limit |
| --- | ---: | ---: | ---: | ---: |
| `/me` | 767156 | 238571 | 890880 | 276480 |
| `/news` | 765367 | 237599 | 880640 | 276480 |
| `/events` | 765851 | 237964 | 890880 | 276480 |
| `/search` | 765851 | 237964 | 890880 | 276480 |
| `/admin/catalog` | 1654898 | 492619 | 1904640 | 573440 |
| `/admin/studio/furni` | 1241312 | 391541 | 1433600 | 450560 |
Configured limits are positive integer bytes; `null` explicitly means observe-only. `scripts/performance-budgets.json` remains `mode: informational`. Exceeding a limit produces `over-budget` and a warning, with exit code 0. Missing production `BUILD_ID`, unsupported manifests, missing routes or missing referenced assets produce `unavailable` with a reason and **no partial/zero total**, also exit code 0. Malformed budget configuration or an unwritable output directory fails the command. This keeps initial CI reporting non-blocking while preventing invalid configuration from quietly disabling limits.
Synthetic tests cover shared-chunk deduplication, exact byte/gzip calculations, route bootstrap selection, missing data, safe parsing and CLI exit behavior. Run `pnpm exec vitest run --coverage.enabled=false scripts/performance-report.test.mjs`.