Unwrapped snippet_edit from DOMContentLoaded handler

Also removed the redundant Jest spec

app/assets/javascripts/snippet/snippet_edit.js

 import ZenMode from '~/zen_mode';
-import { SnippetEditInit } from '~/snippets';
+import SnippetsEdit from '~/snippets/components/edit.vue';
+import SnippetsAppFactory from '~/snippets';
 
-document.addEventListener('DOMContentLoaded', () => {
-  SnippetEditInit();
-  new ZenMode(); // eslint-disable-line no-new
-});
+SnippetsAppFactory(document.getElementById('js-snippet-edit'), SnippetsEdit);
+new ZenMode(); // eslint-disable-line no-new

app/assets/javascripts/snippets/index.js

@@ -44,11 +44,3 @@ export default function appFactory(el, Component) {
     },
   });
 }
-
-export const SnippetEditInit = () => {
-  import('./components/edit.vue')
-    .then(({ default: SnippetsEdit }) => {
-      appFactory(document.getElementById('js-snippet-edit'), SnippetsEdit);
-    })
-    .catch(() => {});
-};

spec/frontend/snippet/snippet_edit_spec.js

-import '~/snippet/snippet_edit';
-import { triggerDOMEvent } from 'jest/helpers/dom_events_helper';
-import { SnippetEditInit } from '~/snippets';
-
-jest.mock('~/snippets');
-jest.mock('~/gl_form');
-
-describe('Snippet edit form initialization', () => {
-  beforeEach(() => {
-    setFixtures('<div class="snippet-form"></div>');
-  });
-
-  it('correctly initializes Vue Snippet Edit form', () => {
-    SnippetEditInit.mockClear();
-
-    triggerDOMEvent('DOMContentLoaded');
-
-    expect(SnippetEditInit).toHaveBeenCalled();
-  });
-});