Beginnings of a node-based bootstrapper for apps, abandoned for better bash scripting but there is a handy log function here and a few patterns useful when working with child_process sync

wip-abandoned-node-app-bootstrapper.js

const fs = require('fs')
const exec = (cmd) => require('child_process').execSync(cmd, { shell: '/bin/bash' })

try {
	let nodePath = exec('which node').toString().replace('\n', '')
	let nodeVer = exec('node -v').toString().replace('\n', '')
	const expectedNodeVer = fs.readFileSync('.nvmrc', 'utf-8').replace('\n', '')
	const npmVer = exec('npm -v').toString().replace('\n', '')
	const nodeVerComparison = versionCompare(nodeVer.substring(1), expectedNodeVer.substring(1))

	log('INFO', `Detected node ${nodeVer} at ${nodePath}`)
	log('INFO', `Detected npm ${npmVer}`)

	if (nodeVerComparison === -1) {
		log('ERROR', `Using node ${bold(nodeVer)}, expected ${bold(expectedNodeVer)}`)

		log('>', 'Checking for Node Version Manager (nvm)...')
		const nvmInfo = exec('command -v nvm').toString().replace('\n', '')
		log('>', `Detected nvm at ${nvmInfo}`)
		log('>', `nvm: Switching to ${expectedNodeVer}...`)
		exec(`npm run setup-env`)
		// execSync(`nvm use ${expectedNodeVer}`)
		// let exitCode = spawn(`nvm install ${expectedNodeVer}`)

		log(
			'INFO',
			`Detected node ${exec('source ~/.bashrc && node -v')
				.toString()
				.replace('\n', '')} at ${nodePath}`,
		)
	} else if (nodeVerComparison === 1) {
		log('WARN', `node ${bold(nodeVer)} is newer, expected ${bold(expectedNodeVer)} in .nvmrc`)
	} else {
		log('OK', `Using node ${bold(nodeVer)} (npm ${npmVer}) at ${ul(nodePath)}`)
	}

	log('OK', nodeVer)
	log('OK', expectedNodeVer)
	log(exec('which bash && $0'))
} catch (err) {
	log('ERROR', err)
}

function log(level, msg) {
	const levels = {
		INFO: `\x1b[37m[INFO]\x1b[0m`,
		OK: '[\x1b[32mOK\x1b[0m]',
		WARN: '[\x1b[33mWARN\x1b[0m]',
		ERROR: '[\x1b[31mERROR\x1b[0m]',
	}
	const timestamp = new Date().toISOString().slice(11).substring(8, 0)
	console.log(`${levels[level] || `[${level}]`} ${msg || ''}`)
}

function ul(str) {
	return `\x1b[4m${str}\x1b[0m`
}

function bold(str) {
	return `\x1b[1m${str}\x1b[0m`
}

function versionCompare(v1, v2) {
	const v1Parts = v1.split('.')
	const v2Parts = v2.split('.')
	const length = Math.max(v1Parts.length, v2Parts.length)
	for (let i = 0; i < length; i++) {
		const value = (parseInt(v1Parts[i]) || 0) - (parseInt(v2Parts[i]) || 0)
		if (value < 0) return -1
		if (value > 0) return 1
	}
	return 0
}