Pipes are binary safe

compress.js

// Compress a given string using the lzma program, and return the compressed contents.

const { spawn } = require('child_process')


const compress = str => new Promise((resolve, reject) => {

    const lzma = spawn('cat',
        { stdio: ["pipe", "pipe", "inherit"] })

    lzma.on('error', err => {
        reject(err)
    })

    lzma.on('exit', (code, signal) => {
        if (code) {
            reject(code)
        }
        else if (signal) {
            reject(signal)
        }
        else {
            resolve(Buffer.concat(compressed))
        }
    })

    lzma.stdin.write(str)
    lzma.stdin.end()

    const compressed = []
    lzma.stdout.on('data', data => { compressed.push(data) })

})

module.exports = compress

const b = Buffer.alloc(256)
for (let i = 0; i < 256; i++) { b[i] = i }
compress(b).then(c => console.log(c.toString('hex')))