named-exports.js

(function(){/*
 * Named exports support for legacy module formats in SystemJS 2.0
 * 
 * Note: This extra is deprecated as the behaviour is now the default in core,
 *       so will be removed in the next major.
 */
(function (global) {
  var systemJSPrototype = global.System.constructor.prototype;

  // hook System.register to know the last declaration binding
  var lastRegisterDeclare;
  var systemRegister = systemJSPrototype.register;
  systemJSPrototype.register = function (name, deps, declare) {
    lastRegisterDeclare = typeof name === 'string' ? declare : deps;
    systemRegister.apply(this, arguments);
  };

  var getRegister = systemJSPrototype.getRegister;
  systemJSPrototype.getRegister = function () {
    var register = getRegister.call(this);
    // if it is an actual System.register call, then its ESM
    // -> dont add named exports
    if (!register || register[1] === lastRegisterDeclare || register[1].length === 0)
      return register;

    // otherwise it was provided by a custom instantiator
    // -> extend the registration with named exports support
    var registerDeclare = register[1];
    register[1] = function (_export, _context) {
      // hook the _export function to note the default export
      var defaultExport, hasDefaultExport = false;
      var declaration = registerDeclare.call(this, function (name, value) {
        if (typeof name === 'object' && name && name.__useDefault)
          defaultExport = name.default, hasDefaultExport = true;
        else if (name === 'default')
          defaultExport = value;
        else if (name === '__useDefault')
          hasDefaultExport = true;
        _export(name, value);
      }, _context);
      // hook the execute function
      var execute = declaration.execute;
      if (execute)
        declaration.execute = function () {
          execute.call(this);
          // do a bulk export of the default export object
          // to export all its names as named exports

          if (hasDefaultExport)
            for (var exportName in defaultExport) {
              if (
                Object.prototype.hasOwnProperty.call(defaultExport,  exportName) // Check if epoxrt name is not inherited, safe for Object.create(null)
                && exportName !== 'default' // default is not a named export
              ) {
                _export(exportName, defaultExport[exportName]);
              }
            }
        };
      return declaration;
    };
    return register;
  };
})(typeof self !== 'undefined' ? self : global);}());