Node script to check npm version of package (expects piped in versions from npm)

vcheck.js

'use strict';

const version = process.argv[2];

// Simple script to exit non-zero if the given version
// usage: npm view [package] versions | node vcheck [version]
// eg: npm view synthetix versions | node vcheck 2.4.1
process.stdin
	.resume()
	.setEncoding('utf8')
	.on('data', function(data) {
		const versions = JSON.parse(data.replace(/'/g, '"'));
		if (versions.indexOf(version) >= 0) {
			process.stdout.write(`${version} already published.\n`);
			process.exitCode = 1;
		}
	});