@trinitymirrordigital/dragonfly-jest-config/lib/helpers/sizing.js

Jest config for dragonfly projects

/* eslint-disable no-underscore-dangle */
Object.defineProperty(window.HTMLElement.prototype, 'clientWidth', {
  get() {
    return this._MockClientWidth || parseInt(this.style.width, 10) || 0;
  },
});

Object.defineProperty(window.HTMLElement.prototype, 'clientHeight', {
  get() {
    return this._MockClientHeight || parseInt(this.style.height, 10) || 0;
  },
});

Object.assign(window.HTMLElement.prototype, {
  getBoundingClientRect() {
    return this._MockClientRect;
  },
  _MockClientRect: { left: 0, top: 0, right: 0, bottom: 0, width: 0, height: 0 },
});

/* eslint-enable no-underscore-dangle */