terinjokes/gulp-license

'use strict';
var defaults = require('defaults');
var through = require('through2');
var licenses = require('./lib/licenses');
var prefixStream = require('./lib/prefix-stream');

module.exports = function (type, options) {
  var opts = defaults(options, {
    year: new Date().getFullYear(),
    license: type
  });
  var licenseKey = options.tiny ? 'tiny' : type.toLowerCase();

  function license(file, encoding, callback) {
    if (file.isNull()) {
      return callback(null, file);
    }

    var template = licenses[licenseKey];

    if (!template) {
      return callback(new Error('License ' + licenseKey + ' does not exist'));
    }

    if (file.isBuffer()) {
      file.contents = new Buffer(template(opts) + file.contents);
    }

    if (file.isStream()) {
      file.contents = file.contents.pipe(prefixStream(template(opts)));
    }

    return callback(null, file);
  }

  return through.obj(license);
};