Fixes broken tests of quick_submit_spec and reduces tech debt

spec/javascripts/behaviors/quick_submit_spec.js

-/* eslint-disable space-before-function-paren, no-var, no-return-assign, comma-dangle, jasmine/no-spec-dupes, new-cap, max-len */
-
 import '~/behaviors/quick_submit';
 
-(function() {
-  describe('Quick Submit behavior', function() {
-    var keydownEvent;
-    preloadFixtures('issues/open-issue.html.raw');
-    beforeEach(function() {
-      loadFixtures('issues/open-issue.html.raw');
-      $('form').submit(function(e) {
+describe('Quick Submit behavior', () => {
+  const keydownEvent = (options = { keyCode: 13, metaKey: true }) => $.Event('keydown', options);
+
+  preloadFixtures('merge_requests/merge_request_with_task_list.html.raw');
+
+  beforeEach(() => {
+    loadFixtures('merge_requests/merge_request_with_task_list.html.raw');
+    $('form').submit((e) => {
       // Prevent a form submit from moving us off the testing page
-        return e.preventDefault();
+      e.preventDefault();
     });
     this.spies = {
-        submit: spyOnEvent('form', 'submit')
+      submit: spyOnEvent('form', 'submit'),
     };
 
     this.textarea = $('.js-quick-submit textarea').first();
   });
-    it('does not respond to other keyCodes', function() {
+
+  it('does not respond to other keyCodes', () => {
     this.textarea.trigger(keydownEvent({
-        keyCode: 32
+      keyCode: 32,
     }));
-      return expect(this.spies.submit).not.toHaveBeenTriggered();
+    expect(this.spies.submit).not.toHaveBeenTriggered();
   });
-    it('does not respond to Enter alone', function() {
+
+  it('does not respond to Enter alone', () => {
     this.textarea.trigger(keydownEvent({
       ctrlKey: false,
-        metaKey: false
+      metaKey: false,
     }));
-      return expect(this.spies.submit).not.toHaveBeenTriggered();
+    expect(this.spies.submit).not.toHaveBeenTriggered();
   });
-    it('does not respond to repeated events', function() {
+
+  it('does not respond to repeated events', () => {
     this.textarea.trigger(keydownEvent({
-        repeat: true
+      repeat: true,
     }));
-      return expect(this.spies.submit).not.toHaveBeenTriggered();
+    expect(this.spies.submit).not.toHaveBeenTriggered();
   });
-    it('disables input of type submit', function() {
+
+  it('disables input of type submit', () => {
     const submitButton = $('.js-quick-submit input[type=submit]');
     this.textarea.trigger(keydownEvent());
 
     expect(submitButton).toBeDisabled();
   });
-    it('disables button of type submit', function() {
+  it('disables button of type submit', () => {
     const submitButton = $('.js-quick-submit input[type=submit]');
     this.textarea.trigger(keydownEvent());
 
     expect(submitButton).toBeDisabled();
   });
-    it('only clicks one submit', function() {
+  it('only clicks one submit', () => {
     const existingSubmit = $('.js-quick-submit input[type=submit]');
     // Add an extra submit button
     const newSubmit = $('<button type="submit">Submit it</button>');
@@ -66,54 +69,42 @@ import '~/behaviors/quick_submit';
   // We cannot stub `navigator.userAgent` for CI's `rake karma` task, so we'll
   // only run the tests that apply to the current platform
   if (navigator.userAgent.match(/Macintosh/)) {
-      it('responds to Meta+Enter', function() {
+    describe('In Macintosh', () => {
+      it('responds to Meta+Enter', () => {
         this.textarea.trigger(keydownEvent());
         return expect(this.spies.submit).toHaveBeenTriggered();
       });
-      it('excludes other modifier keys', function() {
+
+      it('excludes other modifier keys', () => {
         this.textarea.trigger(keydownEvent({
-          altKey: true
+          altKey: true,
         }));
         this.textarea.trigger(keydownEvent({
-          ctrlKey: true
+          ctrlKey: true,
         }));
         this.textarea.trigger(keydownEvent({
-          shiftKey: true
+          shiftKey: true,
         }));
         return expect(this.spies.submit).not.toHaveBeenTriggered();
       });
+    });
   } else {
-      it('responds to Ctrl+Enter', function() {
+    it('responds to Ctrl+Enter', () => {
       this.textarea.trigger(keydownEvent());
       return expect(this.spies.submit).toHaveBeenTriggered();
     });
-      it('excludes other modifier keys', function() {
+
+    it('excludes other modifier keys', () => {
       this.textarea.trigger(keydownEvent({
-          altKey: true
+        altKey: true,
       }));
       this.textarea.trigger(keydownEvent({
-          metaKey: true
+        metaKey: true,
       }));
       this.textarea.trigger(keydownEvent({
-          shiftKey: true
+        shiftKey: true,
       }));
       return expect(this.spies.submit).not.toHaveBeenTriggered();
     });
   }
-    return keydownEvent = function(options) {
-      var defaults;
-      if (navigator.userAgent.match(/Macintosh/)) {
-        defaults = {
-          keyCode: 13,
-          metaKey: true
-        };
-      } else {
-        defaults = {
-          keyCode: 13,
-          ctrlKey: true
-        };
-      }
-      return $.Event('keydown', $.extend({}, defaults, options));
-    };
-  });
-}).call(window);
+});