harmonious/index.js

Ensure that node is run as the correct version, and uses --harmony, if needed

var log = require('npmlog');
var semver = require('semver');
var spawn = require('child_process').spawn;
var path = require('path');
var pkg = require(path.resolve(path.dirname(module.parent.filename), 'package'));

log.heading = pkg.name;
log.level = process.env.LOG_LEVEL || 'info';

module.exports = function (_id) {
  var id = require.resolve(path.resolve(path.dirname(module.parent.filename), _id));
  var child;

  if (!~process.execArgv.indexOf('--harmony') && semver.lt(process.version, '0.12.0')) {
    log.verbose('harmonious', 'spawning.', 'harmony required for', process.version);
    log.verbose('harmonious', pkg.engines.node);
    log.verbose('harmonious', process.version);

    if (!pkg.engines || !pkg.engines.node) {
      log.verbose('harmonious', 'no valid pkg.engines.node found');
      child = spawn('n', [ 'latest' ]);
      child.on('exit', function (code, signal) {
        reSpawn(id);
      });
    }

    else if (semver.satisfies(process.version, pkg.engines.node)) {
      log.verbose('harmonious', 'version already satisfied');
      reSpawn(id);
    }

    else if (semver.gtr('0.12.0', pkg.engines.node) && semver.satisfies('0.11.13', pkg.engines.node)) {
      child = spawn('n', [ '0.11' ]);
      child.on('exit', function (code, signal) {
        reSpawn(id);
      });
    }

    else if (semver.gtr('0.11.0', pkg.engines.node) && semver.satisfies('0.10.29', pkg.engines.node)) {
      child = spawn('n', [ '0.10' ]);
      child.on('exit', function (code, signal) {
        reSpawn(id);
      });
    }

    else if (semver.gtr('0.10.0', pkg.engines.node) && semver.satisfies('0.8.27', pkg.engines.node)) {
      child = spawn('n', [ '0.8' ]);
      child.on('exit', function (code, signal) {
        reSpawn(id);
      });
    }

    else if (semver.gtr('0.8.6', pkg.engines.node)) {
      log.error('range', 'I\'m not going to load anything older than 0.8.6. sorry');
    }

    else {
      // default case: load latest
      child = spawn('n', [ 'latest' ]);
      child.on('exit', function (code, signal) {
        reSpawn(id);
      });
    }
  }
  else {
    reSpawn(id);
  }
};

function reSpawn (id) {
  var child = spawn(process.execPath, [ "--harmony", id ].concat(process.argv.slice(2)), {
    cwd: process.cwd(),
    stdio: 'inherit'
  });
}