johnny-cli/src/helpers/spawn-npm.js

CLI for Johnny Deps

// @flow
import R from 'ramda';
import {spawn} from 'child_process';

export default async (args: Array<string>) => new Promise(async (resolve, reject) => {
	const
		spawned = spawn('npm', args);

	let
		stderrData = '',
		stdoutData = '';

	spawned.stdout.on('data', data => stdoutData += data);
	spawned.stderr.on('data', data => stderrData += data);
	spawned.on('close', resolve);

	stderrData = (
		await new Promise(stdErrResolve => spawned.stderr.on('end', () => stdErrResolve(stderrData)))
	).replace(/\n+$/, '');

	stdoutData = (
		await new Promise(stdOutResolve => spawned.stdout.on('end', () => stdOutResolve(stdoutData)))
	).replace(/\n+$/, '');

	if(stdoutData)
		console.log('\n' + stdoutData);

	// Ignore output with only WARNs and empty lines
	if(stderrData && !R.all(line => !line || line.match(/^npm WARN.*/gi), stderrData.split('\n')))
		reject(stderrData);
	else if(stderrData)
		console.log(`\n${stderrData}\n`);
});