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) {
-        // Prevent a form submit from moving us off the testing page
-        return e.preventDefault();
-      });
-      this.spies = {
-        submit: spyOnEvent('form', 'submit')
-      };
+describe('Quick Submit behavior', () => {
+  const keydownEvent = (options = { keyCode: 13, metaKey: true }) => $.Event('keydown', options);
 
-      this.textarea = $('.js-quick-submit textarea').first();
-    });
-    it('does not respond to other keyCodes', function() {
-      this.textarea.trigger(keydownEvent({
-        keyCode: 32
-      }));
-      return expect(this.spies.submit).not.toHaveBeenTriggered();
-    });
-    it('does not respond to Enter alone', function() {
-      this.textarea.trigger(keydownEvent({
-        ctrlKey: false,
-        metaKey: false
-      }));
-      return expect(this.spies.submit).not.toHaveBeenTriggered();
-    });
-    it('does not respond to repeated events', function() {
-      this.textarea.trigger(keydownEvent({
-        repeat: true
-      }));
-      return expect(this.spies.submit).not.toHaveBeenTriggered();
-    });
-    it('disables input of type submit', function() {
-      const submitButton = $('.js-quick-submit input[type=submit]');
-      this.textarea.trigger(keydownEvent());
+  preloadFixtures('merge_requests/merge_request_with_task_list.html.raw');
 
-      expect(submitButton).toBeDisabled();
+  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
+      e.preventDefault();
     });
-    it('disables button of type submit', function() {
-      const submitButton = $('.js-quick-submit input[type=submit]');
-      this.textarea.trigger(keydownEvent());
+    this.spies = {
+      submit: spyOnEvent('form', 'submit'),
+    };
 
-      expect(submitButton).toBeDisabled();
-    });
-    it('only clicks one submit', function() {
-      const existingSubmit = $('.js-quick-submit input[type=submit]');
-      // Add an extra submit button
-      const newSubmit = $('<button type="submit">Submit it</button>');
-      newSubmit.insertAfter(this.textarea);
+    this.textarea = $('.js-quick-submit textarea').first();
+  });
 
-      const oldClick = spyOnEvent(existingSubmit, 'click');
-      const newClick = spyOnEvent(newSubmit, 'click');
+  it('does not respond to other keyCodes', () => {
+    this.textarea.trigger(keydownEvent({
+      keyCode: 32,
+    }));
+    expect(this.spies.submit).not.toHaveBeenTriggered();
+  });
 
-      this.textarea.trigger(keydownEvent());
+  it('does not respond to Enter alone', () => {
+    this.textarea.trigger(keydownEvent({
+      ctrlKey: false,
+      metaKey: false,
+    }));
+    expect(this.spies.submit).not.toHaveBeenTriggered();
+  });
 
-      expect(oldClick).not.toHaveBeenTriggered();
-      expect(newClick).toHaveBeenTriggered();
-    });
-    // 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() {
-        this.textarea.trigger(keydownEvent());
-        return expect(this.spies.submit).toHaveBeenTriggered();
-      });
-      it('excludes other modifier keys', function() {
-        this.textarea.trigger(keydownEvent({
-          altKey: true
-        }));
-        this.textarea.trigger(keydownEvent({
-          ctrlKey: true
-        }));
-        this.textarea.trigger(keydownEvent({
-          shiftKey: true
-        }));
-        return expect(this.spies.submit).not.toHaveBeenTriggered();
-      });
-    } else {
-      it('responds to Ctrl+Enter', function() {
+  it('does not respond to repeated events', () => {
+    this.textarea.trigger(keydownEvent({
+      repeat: true,
+    }));
+    expect(this.spies.submit).not.toHaveBeenTriggered();
+  });
+
+  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', () => {
+    const submitButton = $('.js-quick-submit input[type=submit]');
+    this.textarea.trigger(keydownEvent());
+
+    expect(submitButton).toBeDisabled();
+  });
+  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>');
+    newSubmit.insertAfter(this.textarea);
+
+    const oldClick = spyOnEvent(existingSubmit, 'click');
+    const newClick = spyOnEvent(newSubmit, 'click');
+
+    this.textarea.trigger(keydownEvent());
+
+    expect(oldClick).not.toHaveBeenTriggered();
+    expect(newClick).toHaveBeenTriggered();
+  });
+  // 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/)) {
+    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({
-          metaKey: true
+          ctrlKey: 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);
+    });
+  } else {
+    it('responds to Ctrl+Enter', () => {
+      this.textarea.trigger(keydownEvent());
+      return expect(this.spies.submit).toHaveBeenTriggered();
+    });
+
+    it('excludes other modifier keys', () => {
+      this.textarea.trigger(keydownEvent({
+        altKey: true,
+      }));
+      this.textarea.trigger(keydownEvent({
+        metaKey: true,
+      }));
+      this.textarea.trigger(keydownEvent({
+        shiftKey: true,
+      }));
+      return expect(this.spies.submit).not.toHaveBeenTriggered();
+    });
+  }
+});