Ember Source Code Reading

detect-ie11-edge.ts

// `window.ActiveXObject` is "falsey" in IE11 (but not `undefined` or `false`)
// `"ActiveXObject" in window` returns `true` in all IE versions
// only IE11 will pass _both_ of these conditions

declare global {
  interface Window {
    ActiveXObject: any;
  }
}
export const isIE11 = !window.ActiveXObject && 'ActiveXObject' in window;
export const isEdge = /Edge/.test(navigator.userAgent);

detect-nodejs.js

let isNode =
    typeof window === 'undefined' &&
    typeof process !== 'undefined' &&
    {}.toString.call(process) === '[object process]';

ember-snippets.js

// I have made an attempt to go through ember.js source code.
// Below snippets are taken from the same which do specific tasks.

empty-object.js

// Creates object with no constructor
let empty1 = Object.create(null);

// Outputs: undefined
console.log(empty2.constructor)

let empty2 = {};

// Outputs: ƒ Object() { [native code] }
console.log(empty2.constructor)

/*
* Reference Link
* http://adripofjavascript.com/blog/drips/creating-objects-without-prototypes.html
*/

has-dom.ts

// check if window exists and actually is the global
export default typeof self === 'object' &&
  self !== null &&
  (self as any).Object === Object &&
  typeof Window !== 'undefined' &&
  self.constructor === Window &&
  typeof document === 'object' &&
  document !== null &&
  self.document === document &&
  typeof location === 'object' &&
  location !== null &&
  self.location === location &&
  typeof history === 'object' &&
  history !== null &&
  self.history === history &&
  typeof navigator === 'object' &&
  navigator !== null &&
  self.navigator === navigator &&
  typeof navigator.userAgent === 'string';