ohif-viewer/platform/viewer/cypress/support/index.js

// ***********************************************************
// This example support/index.js is processed and
// loaded automatically before your test files.
//
// This is a great place to put global configuration and
// behavior that modifies Cypress.
//
// You can change the location of this file or turn off
// automatically serving support files with the
// 'supportFile' configuration option.
//
// You can read more here:
// https://on.cypress.io/configuration
// ***********************************************************

import './commands';

Cypress.on('window:before:load', window => {
  // Override our `getContext` function so all contexts that are webGl are
  // Created with `preserveDrawingBuffer = true`; this is required for percy
  // Snapshot
  window.HTMLCanvasElement.prototype.getContext = (function(oldGetContextFn) {
    return function(type, attrs) {
      attrs = attrs || {};
      if (
        type === 'webgl' ||
        type === 'webgl2' ||
        type === 'experimental-webgl'
      ) {
        attrs.preserveDrawingBuffer = true;
      }
      return oldGetContextFn.apply(this, [type, attrs]);
    };
  })(HTMLCanvasElement.prototype.getContext);
});