jsnap.js

#!/usr/bin/env node
var fs = require('fs')
var program = require('commander')
var instrument = require('./lib/instrument')
var spawn = require('child_process').spawn
var temp = require('temp')
var phantomjs = require('phantomjs-prebuilt')

temp.track(); // ensure temporary files are deleted on exit

/**
 * Options:
 * - files {string[]} Names of JavaScript files to concatenate and execute
 * - stdio: standard I/O to pass to the subprocess
 * Returns a subprocess
 */
function jsnap(options) {
    var runtime = options.runtime || 'browser';

    var chunks = []

    options.files.forEach(function (file) {
        chunks.push(fs.readFileSync(file, 'utf8'))
    })
    var instrumentedCode = instrument(chunks.join('\n'), {runtime: runtime})

    var tempFilePath;
    if (options.tmp) {
        fs.writeFileSync(options.tmp, instrumentedCode)
        tempFilePath = options.tmp;
    } else {
        var tempFile = temp.openSync('jsnap')
        fs.writeSync(tempFile.fd, instrumentedCode)
        tempFilePath = tempFile.path;
    }

    var subproc;

    if (runtime === 'node') {
        subproc = spawn('node', [tempFilePath], {stdio: options.stdio})
    } else if (runtime === 'browser') {
        subproc = spawn(phantomjs.path, [__dirname + '/lib/jsnap.phantom.js', tempFilePath], {stdio: options.stdio})
    } else {
        throw new Error("Invalid runtime: " + runtime)
    }

    return subproc;
}
module.exports = jsnap


function main() {
    program.version('0.1')
        .option('--runtime [node|browser]', 'Runtime environment to use (default: browser)', String, 'browser')
        .option('--tmp [FILE]', 'Use the given file as temporary')
        .parse(process.argv)

    var options = {
        runtime: program.runtime,
        tmp: program.tmp,
        stdio: ['ignore', 1, 2],
        files: program.args
    }
    var subproc = jsnap(options)
    subproc.on('error', function(e) {
        console.error(e)
    })
}


if (require.main === module) {
    main();
}