chore: compress and lazy load client code (#2425)

apps/client/scripts/compress-dist.mjs

@@ -0,0 +1,48 @@
+import { promises as fs } from "node:fs";
+import { join, extname } from "node:path";
+import { promisify } from "node:util";
+import zlib from "node:zlib";
+
+const gzip = promisify(zlib.gzip);
+const brotli = promisify(zlib.brotliCompress);
+
+const DIST = new URL("../dist", import.meta.url).pathname;
+// index.html is rewritten by the server at boot, so html must not be precompressed
+const COMPRESSIBLE = new Set([".js", ".css", ".svg", ".json", ".txt", ".map"]);
+const MIN_SIZE = 1024;
+
+async function* walk(dir) {
+  for (const entry of await fs.readdir(dir, { withFileTypes: true })) {
+    const path = join(dir, entry.name);
+    if (entry.isDirectory()) yield* walk(path);
+    else yield path;
+  }
+}
+
+const files = [];
+for await (const file of walk(DIST)) {
+  if (!COMPRESSIBLE.has(extname(file))) continue;
+  const { size } = await fs.stat(file);
+  if (size >= MIN_SIZE) files.push(file);
+}
+
+await Promise.all(
+  files.map(async (file) => {
+    const content = await fs.readFile(file);
+    const [gz, br] = await Promise.all([
+      gzip(content, { level: 9 }),
+      brotli(content, {
+        params: {
+          [zlib.constants.BROTLI_PARAM_QUALITY]: 11,
+          [zlib.constants.BROTLI_PARAM_SIZE_HINT]: content.length,
+        },
+      }),
+    ]);
+    await Promise.all([
+      fs.writeFile(`${file}.gz`, gz),
+      fs.writeFile(`${file}.br`, br),
+    ]);
+  }),
+);
+
+console.log(`precompressed ${files.length} assets (.gz/.br)`);