react.dev/extractCode.js

var argv = require('optimist').argv;
var fs = require('fs');

var CODE_SAMPLE = /```[\S]+\s*[\s\S]*?```/g;
var PARTS = /```[\S]+\s*\/\/\s+(.+?)\n([\s\S]*?)```/;

function truncate(s, n) {
    n = n || 256
    if (s.length < n) {
	return s;
    }
    return s.substring(0, n) + '...';
}

function main(dest, filenames) {
    if (!dest) {
	throw new Error('no dest provided');
    }
    console.log(filenames);
    
    filenames.map(function (filename) {
		var content = fs.readFileSync(filename).toString('utf8');
		var codeSamples = content.match(CODE_SAMPLE);

		
		codeSamples.map(function (codeSample) {
		    // Do a little jank preprocessing
		    codeSample = codeSample.replace('<!--', '//').replace(' -->', '');
		    var extracted = codeSample.match(PARTS);
		    if (!extracted) {
			throw new Error('Code sample did not match correct format in ' + filename + ': ' + truncate(codeSample));
		    }
		    var filename = extracted[1];
		    var content = extracted[2].replace(/\*\*/g, '');
		    fs.writeFileSync(argv.dest + '/' + filename, content);
		});
    });
}

main(argv.dest, argv._);