compeko.js

// compeko - pack JavaScript into a self-extracting html+deflate
// v1.1.0

// Copyright (c) 2022 0b5vr
// SPDX-License-Identifier: MIT

// Usage:
// - prepare a js code, which will be fed into `eval`
// - install `node-zopfli` as your (dev-) dependency
// - run: `node compeko.js input.js output.html`

// Shoutouts to:
// - gasman, for pnginator ... https://gist.github.com/gasman/2560551
// - Charles Boccato, for JsExe ... https://www.pouet.net/prod.php?which=59298
// - subzey, for fetchcrunch ... https://github.com/subzey/fetchcrunch
//   - Achieves almost the same concept. Referred several tricks of the header code

// Source: https://gist.github.com/0b5vr/09ee96ca2efbe5bf9d64dad7220e923b
// Small modifications made
// =================================================================================================

// -- sanity check ---------------------------------------------------------------------------------
try {
    require( 'node-zopfli' );
  } catch ( e ) {
    console.error( e );
    console.error( `
  \x1b[31mMake sure you installed \x1b[35mnode-zopfli\x1b[31m !\x1b[0m` );
    process.exit( 1 );
  }
  
  if ( process.argv[ 3 ] == null ) {
    console.error( '\x1b[31mUsage: \x1b[35mnode compeko.js input.js output.html\x1b[0m' );
    process.exit( 1 );
  }
  
  // -- modules --------------------------------------------------------------------------------------
  const fs = require( 'fs' );
  const { resolve } = require( 'path' );
  const zopfli = require( 'node-zopfli' );
  
  // -- main -----------------------------------------------------------------------------------------
  console.info( 'Compressing the file...' );
  
  ( async () => {
    const inputPath = resolve( process.cwd(), process.argv[ 2 ] );
    const outputPath = resolve( process.cwd(), process.argv[ 3 ] );
  
    const inputFile = await fs.promises.readFile( inputPath );
    const inputSize = inputFile.length;
    console.info( `Input size: \x1b[32m${ inputSize.toLocaleString() } bytes\x1b[0m` );
  
    const compressed = await zopfli.deflate( inputFile, {
      numiterations: 100, // increase this number to shave your last bytes
      blocksplitting: true,
    } );
  
    // extra: output deflate
    {
      const outputPathBase = outputPath.match( /(.*)\..+$/ )[ 1 ];
      const deflatePath = `${ outputPathBase }.deflate.bin`;
      await fs.promises.writeFile( deflatePath, compressed );
    }
  
    const header = `<svg onload="fetch('#').then(t=>t.blob()).then(t=>new Response(t.slice(158).stream().pipeThrough(new DecompressionStream('deflate-raw'))).text()).then(eval)">`;
    const headerBuffer = Buffer.alloc( header.length );
    headerBuffer.write( header );
  
    const concated = Buffer.concat( [ headerBuffer, compressed ] );
  
    const outputSize = concated.length;
    const percentage = ( 100.0 * ( outputSize / inputSize ) ).toFixed( 3 );
    console.info( `Output size: \x1b[32m${ outputSize.toLocaleString() } bytes\x1b[0m (${ percentage } %)` );
  
    await fs.promises.writeFile( outputPath, concated );
  
    console.info( 'Done \x1b[32m✓\x1b[0m' );
  } )();