Precompress production assets

Author: adsharma

README.md

@@ -21,4 +21,11 @@ The `dev` command automatically copies the multithreaded WASM modules from `@lad
 pnpm build
 ```
 
-This builds both the WASM modules and the production bundle.
+This builds both the WASM modules and the production bundle, then writes
+precompressed `.gz` and `.br` versions of text/WASM assets in `dist/`.
+
+The web server or CDN must serve those files with `Content-Encoding: gzip` or
+`Content-Encoding: br` for browsers to use them. GitHub Pages does not expose
+custom response-header configuration from this repository; use a CDN or static
+host that supports precompressed assets if you need to control compression
+explicitly.

package.json

@@ -7,8 +7,9 @@
     "predev": "pnpm run build:wasm",
     "build:wasm": "cp node_modules/@ladybugdb/wasm-core/multithreaded/index.js lib/index.js && cp node_modules/@ladybugdb/wasm-core/multithreaded/lbug_wasm_worker.js lib/lbug_wasm_worker.js && cp node_modules/@ladybugdb/wasm-core/multithreaded/sync/index.js sync/index.js",
     "dev": "vite",
-    "build": "pnpm run build:wasm && vite build && pnpm run copy:lib",
+    "build": "pnpm run build:wasm && vite build && pnpm run copy:lib && pnpm run compress:dist",
     "copy:lib": "node -e \"const {copyFileSync,mkdirSync,existsSync}=require('fs');const d='dist/lib';if(!existsSync(d))mkdirSync(d,{recursive:true});['index.js','lbug_wasm_worker.js'].forEach(f=>copyFileSync('lib/'+f,d+'/'+f));const s='dist/sync';if(!existsSync(s))mkdirSync(s,{recursive:true});copyFileSync('sync/index.js',s+'/index.js')\"",
+    "compress:dist": "node scripts/compress-dist.mjs",
     "preview": "vite preview"
   },
   "dependencies": {

scripts/compress-dist.mjs

@@ -0,0 +1,69 @@
+import { createReadStream, createWriteStream, statSync } from 'node:fs';
+import { readdir } from 'node:fs/promises';
+import { extname, join } from 'node:path';
+import { pipeline } from 'node:stream/promises';
+import { createBrotliCompress, createGzip, constants } from 'node:zlib';
+
+const DIST_DIR = 'dist';
+const MIN_BYTES = 1024;
+const COMPRESSIBLE_EXTENSIONS = new Set([
+  '.css',
+  '.html',
+  '.js',
+  '.json',
+  '.mjs',
+  '.svg',
+  '.txt',
+  '.wasm',
+  '.xml',
+]);
+
+async function* walk(dir) {
+  for (const entry of await readdir(dir, { withFileTypes: true })) {
+    const path = join(dir, entry.name);
+    if (entry.isDirectory()) {
+      yield* walk(path);
+    } else if (entry.isFile()) {
+      yield path;
+    }
+  }
+}
+
+async function compressFile(path) {
+  await pipeline(
+    createReadStream(path),
+    createGzip({ level: 9 }),
+    createWriteStream(`${path}.gz`),
+  );
+
+  await pipeline(
+    createReadStream(path),
+    createBrotliCompress({
+      params: {
+        [constants.BROTLI_PARAM_QUALITY]: 11,
+      },
+    }),
+    createWriteStream(`${path}.br`),
+  );
+}
+
+let compressedCount = 0;
+
+for await (const path of walk(DIST_DIR)) {
+  if (path.endsWith('.gz') || path.endsWith('.br')) {
+    continue;
+  }
+
+  if (!COMPRESSIBLE_EXTENSIONS.has(extname(path))) {
+    continue;
+  }
+
+  if (statSync(path).size < MIN_BYTES) {
+    continue;
+  }
+
+  await compressFile(path);
+  compressedCount += 1;
+}
+
+console.log(`Compressed ${compressedCount} dist asset${compressedCount === 1 ? '' : 's'}.`);