systemjs/lib/cjs.js

/*
  SystemJS CommonJS Format
*/
(function() {
  // CJS Module Format
  // require('...') || exports[''] = ... || exports.asd = ... || module.exports = ...
  var cjsExportsRegEx = /(?:^\uFEFF?|[^$_a-zA-Z\xA0-\uFFFF.]|module\.)exports\s*(\[['"]|\.)|(?:^\uFEFF?|[^$_a-zA-Z\xA0-\uFFFF.])module\.exports\s*[=,]/;
  // RegEx adjusted from https://github.com/jbrantly/yabble/blob/master/lib/yabble.js#L339
  var cjsRequireRegEx = /(?:^\uFEFF?|[^$_a-zA-Z\xA0-\uFFFF."'])require\s*\(\s*("[^"\\]*(?:\\.[^"\\]*)*"|'[^'\\]*(?:\\.[^'\\]*)*')\s*\)/g;
  var commentRegEx = /(\/\*([\s\S]*?)\*\/|([^:]|^)\/\/(.*)$)/mg;

  function getCJSDeps(source) {
    cjsRequireRegEx.lastIndex = commentRegEx.lastIndex = 0;

    var deps = [];

    // track comments in the source
    var match;
    
    var commentLocations = [];
    if (source.length / source.split('\n').length < 200) {
      while (match = commentRegEx.exec(source))
        commentLocations.push([match.index, match.index + match[0].length]);
    }

    while (match = cjsRequireRegEx.exec(source)) {
      // ensure we're not in a comment location
      var inComment = false;
      for (var i = 0; i < commentLocations.length; i++) {
        if (commentLocations[i][0] < match.index && commentLocations[i][1] > match.index + match[0].length)
          inComment = true;
      }
      if (!inComment)
        deps.push(match[1].substr(1, match[1].length - 2));
    }

    return deps;
  }

  if (typeof window != 'undefined' && typeof document != 'undefined' && window.location)
    var windowOrigin = location.protocol + '//' + (location.protocol == 'file:' && location.hostname[0] != '/' ? '/' : '') + location.hostname + (location.port ? ':' + location.port : '');

  hookConstructor(function(constructor) {
    return function() {
      constructor.call(this);

      // include the node require since we're overriding it
      if (typeof require != 'undefined' && require.resolve && typeof process != 'undefined')
        this._nodeRequire = require;
    };
  });

  hook('normalize', function(normalize) {
    return function (name, parentName) {
      // dynamically load node-core modules when requiring `@node/fs` for example
      if (name.substr(0, 6) == '@node/') {
        if (!this._nodeRequire)
          throw new TypeError('Can only load node core modules in Node.');
        this.set(name, this.newModule(getESModule(this._nodeRequire(name.substr(6)))));
      }
      return normalize.apply(this, arguments);
    };
  });

  hook('instantiate', function(instantiate) {
    return function(load) {
      var loader = this;
      if (!load.metadata.format) {
        cjsExportsRegEx.lastIndex = 0;
        cjsRequireRegEx.lastIndex = 0;
        if (cjsRequireRegEx.exec(load.source) || cjsExportsRegEx.exec(load.source))
          load.metadata.format = 'cjs';
      }

      if (load.metadata.format == 'cjs') {
        var metaDeps = load.metadata.deps || [];
        load.metadata.deps = metaDeps.concat(getCJSDeps(load.source));

        for (var g in load.metadata.globals)
          load.metadata.deps.push(load.metadata.globals[g]);

        load.metadata.executingRequire = true;

        load.metadata.execute = function(require, exports, module) {
          // ensure meta deps execute first
          for (var i = 0; i < metaDeps.length; i++)
            require(metaDeps[i]);
          var address = load.address || '';

          var dirname = address.split('/');
          dirname.pop();
          dirname = dirname.join('/');

          if (windowOrigin && address.substr(0, windowOrigin.length) === windowOrigin) {
            address = address.substr(windowOrigin.length);
            dirname = dirname.substr(windowOrigin.length);
          }
          else if (address.substr(0, 8) == 'file:///') {
            address = address.substr(7);
            dirname = dirname.substr(7);

            // on windows remove leading '/'
            if (isWindows) {
              address = address.substr(1);
              dirname = dirname.substr(1);
            }
          }

          // disable AMD detection
          var define = __global.define;
          __global.define = undefined;

          __global.__cjsWrapper = {
            exports: exports,
            args: [require, exports, module, address, dirname, __global, __global]
          };

          var globals = '';
          if (load.metadata.globals) {
            for (var g in load.metadata.globals)
              globals += 'var ' + g + ' = require("' + load.metadata.globals[g] + '");';
          }

          load.source = "(function(require, exports, module, __filename, __dirname, global, GLOBAL) {" + globals
              + load.source + "\n}).apply(__cjsWrapper.exports, __cjsWrapper.args);";

          __exec.call(loader, load);

          __global.__cjsWrapper = undefined;
          __global.define = define;
        };
      }

      return instantiate.call(loader, load);
    };
  });
})();