add fullscreen partial test

tests/plugins/plugin-fullscreen.test.js

@@ -0,0 +1,41 @@
+const root = '../../';
+
+jest.useFakeTimers();
+
+describe('fullscreen plugin', function(){
+
+  beforeEach(function(){
+    require(root + 'jspsych.js');
+    require(root + 'plugins/jspsych-fullscreen.js');
+    require(root + 'plugins/jspsych-text.js');
+  });
+
+  test('loads correctly', function(){
+    expect(typeof window.jsPsych.plugins['fullscreen']).not.toBe('undefined');
+  });
+
+  // can't test this right now because jsdom doesn't support fullscreen API.
+
+  /*test('launches fullscreen mode by default', function(){
+    var trial = {
+      type: 'fullscreen',
+      delay_after: 0
+    }
+
+    var text = {
+      type: 'text',
+      text: 'fullscreen'
+    }
+
+    jsPsych.init({
+      timeline: [trial, text]
+    });
+
+    expect(document.fullscreenElement).toBeUndefined();
+    console.log(jsPsych.getDisplayElement().requestFullscreen);
+    document.querySelector('#jspsych-fullscreen-btn').dispatchEvent(new MouseEvent('click', {}));
+
+    expect(document.fullscreenElement).not.toBeUndefined();
+  });*/
+
+});