That js file reads a `file.in` input file that contains prop types declarations and outputs an `file.out` file that will act as our shouldComponentUpdate react method.

updater.js

var fs = require('fs');
var lineReader = require('readline').createInterface({
	input: fs.createReadStream('file.in'),
	output: process.stdout,
	terminal: false
});

var fd = fs.openSync('file.out', 'w');
fs.write(fd, 'shouldComponentUpdate(nextProps) {\n  return (\n');
var lineIt = 0;
lineReader.on('line', function (line) {
	if (!line || /^\s*[\/][\/]/.test(line) || line.search(".func") !== -1) {
	    // ^    starting at the beginning of the line
	    // \s*  look for zero or more whitespace characters
	    // [\/]   and then a forward slash /
	    // [\/]   and then another forward slash /
	    // it's a comment so 
	    lineIt ++; // increase the line cnt
	    // and move on
	    if (!line) {
	    	console.log('Found blank row on line: '+lineIt);
	    } else if (line.search(".func") !== -1) {
			console.log('Found function proptype on line: '+lineIt);
	    } else {
	    	console.log('Found comment on line: '+lineIt);
	    }
	} else {
		var lineSplit = line.split(':');
		if (lineSplit) {
			var item = lineSplit[0];
			// console.log('Line from file:', line);
			var lineChangingStr = '';
			if (lineIt !== 0) {
				lineChangingStr = '    ||\n';
			}
			fs.write(fd, lineChangingStr+'    nextProps.'+item+' !== this.props.'+item+'\n');
			lineIt ++;
		}
	}
});
lineReader.on('close', function () {
	fs.write(fd, '  );\n}');
})