src/utils/CharMeasure.test.ts

   1 /**
   2  * @license MIT
   3  */
   4 import jsdom = require('jsdom');
   5 import { assert } from 'chai';
   6 import { ICharMeasure, ITerminal } from '../Interfaces';
   7 import { CharMeasure } from './CharMeasure';
   8
   9 describe('CharMeasure', () => {
  10   let window: Window;
  11   let document: Document;
  12
  13   let container: HTMLElement;
  14   let charMeasure: ICharMeasure;
  15
  16   beforeEach(done => {
  17     jsdom.env('', (err, w) => {
  18       window = w;
  19       document = window.document;
  20       container = document.createElement('div');
  21       document.body.appendChild(container);
  22       charMeasure = new CharMeasure(document, container);
  23       done();
  24     });
  25   });
  26
  27   describe('measure', () => {
  28     it('should set _measureElement on first call', () => {
  29       charMeasure.measure();
  30       assert.isDefined((<any>charMeasure)._measureElement, 'CharMeasure.measure should have created _measureElement');
  31     });
  32
  33     it('should be performed async on first call', done => {
  34       assert.equal(charMeasure.width, null);
  35       charMeasure.measure();
  36       // Mock getBoundingClientRect since jsdom doesn't have a layout engine
  37       (<any>charMeasure)._measureElement.getBoundingClientRect = () => {
  38         return { width: 1, height: 1 };
  39       };
  40       assert.equal(charMeasure.width, null);
  41       setTimeout(() => {
  42         assert.equal(charMeasure.width, 1);
  43         done();
  44       }, 0);
  45     });
  46
  47     it('should be performed sync on successive calls', done => {
  48       charMeasure.measure();
  49       // Mock getBoundingClientRect since jsdom doesn't have a layout engine
  50       (<any>charMeasure)._measureElement.getBoundingClientRect = () => {
  51         return { width: 1, height: 1 };
  52       };
  53       setTimeout(() => {
  54         const firstWidth = charMeasure.width;
  55         // Mock getBoundingClientRect since jsdom doesn't have a layout engine
  56         (<any>charMeasure)._measureElement.getBoundingClientRect = () => {
  57           return { width: 2, height: 2 };
  58         };
  59         charMeasure.measure();
  60         assert.equal(charMeasure.width, firstWidth * 2);
  61         done();
  62       }, 0);
  63     });
  64
  65     it('should NOT do a measure when the parent is hidden', done => {
  66       charMeasure.measure();
  67       setTimeout(() => {
  68         const firstWidth = charMeasure.width;
  69         container.style.display = 'none';
  70         container.style.fontSize = '2em';
  71         charMeasure.measure();
  72         assert.equal(charMeasure.width, firstWidth);
  73         done();
  74       }, 0);
  75     });
  76   });
  77 });