Allow sirv to looks for precompiled gzip and brotli files by default

[istarkov]

This should not change anyting for users who doesnt use brotli or gzip precompiled asset files. But brotli gives real advantages over gzip in compression size.

In absense of sirv config, probably it can be a good default.

For compressing we use following script.

import * as zlib from 'zlib';
import { pipeline } from 'stream';
import { promisify } from 'util';

import * as fs from 'fs';
import { totalist } from 'totalist/sync/index.js';
import yargs from 'yargs';

const supportedAlgs = ['gz', 'br'];

const argv = yargs(process.argv.slice(2))
  .describe('alg', 'Compression algorithm gz or br')
  .choices('alg', supportedAlgs)
  .describe('dir', 'Directory to compress files')
  .string('dir')
  .array('ext')
  .default('ext', ['js', 'css', 'json', 'svg'])
  .demandOption(['alg', 'dir'], 'alg and dir must be provided')
  .check(argv => {
    if (!fs.statSync(argv.dir).isDirectory()) {
      throw new Error(`"${argv.dir}" is not directory`);
    }

    return true; // tell Yargs that the arguments passed the check
  })
  .example([
    ['$0 --alg br --dir .build/assets', 'Use brotli compression'],
    ['$0 --alg gz --dir .build/assets', 'Use gz compression'],
    [
      '$0 --alg gz --dir .build/assets --ext css json',
      'Use gz compression for files with css and json extensions',
    ],
  ]).argv;

const files: string[] = [];

if (!('dir' in argv)) {
  throw new Error('argv is a promise');
}

totalist(argv.dir, (_, abs) => {
  files.push(abs);
});

const pipe = promisify(pipeline);

const compress = async () => {
  const sizes = [];
  for (const file of files) {
    if (
      argv.ext.some(ext => file.endsWith(`.${ext}`)) &&
      !supportedAlgs.some(alg => file.endsWith(`.${alg}`))
    ) {
      const destFile = `${file}.${argv.alg}`;
      const compressionMethod =
        argv.alg === 'gz' ? zlib.createGzip() : zlib.createBrotliCompress();
      const source = fs.createReadStream(file);
      const destination = fs.createWriteStream(destFile);
      await pipe(source, compressionMethod, destination);
      const inSize = Math.round((100 * fs.statSync(file).size) / 1024) / 100;
      const outSize =
        Math.round((100 * fs.statSync(destFile).size) / 1024) / 100;

      sizes.push({ inSize, outSize, file });
    }
  }

  console.table(sizes);
};

compress().then(() => null);

[lukeed]

Technically this means sirv is doing more checks on every request (< 1ms) but that's totally fine 😆 If this part of the app were ever to be exposed to the config layer, it'd be a good thing to expose (with some forced SK overrides)

[benmccann]

@istarkov can you add a patch changeset so that this PR can be merged and released? (pnpx changeset)

[benmccann]

I'm curious if there's any Vite or Rollup plugin that you could use rather than a custom script

[istarkov]

I'm curious if there's any Vite or Rollup plugin that you could use rather than a custom script

Yes some plugins exists https://www.npmjs.com/package/rollup-plugin-brotli and same for gzip,
custom script just allows to use it not only for build assets and for other things too.