Fix duplicate item in protected branch/tag dropdown

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/42157
Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/41989

app/assets/javascripts/create_item_dropdown.js

@@ -65,7 +65,17 @@ export default class CreateItemDropdown {
   getData(term, callback) {
     this.getDataOption(term, (data = []) => {
-      callback(data.concat(this.selectedItem || []));
+      // Ensure the selected item isn't already in the data to avoid duplicates
+      const alreadyHasSelectedItem = this.selectedItem && data.some(item =>
+        item.id === this.selectedItem.id,
+      );
+
+      let uniqueData = data;
+      if (!alreadyHasSelectedItem) {
+        uniqueData = data.concat(this.selectedItem || []);
+      }
+
+      callback(uniqueData);
     });
   }

changelogs/unreleased/42157-41989-fix-duplicate-in-create-item-dropdown.yml

+---
+title: Fix duplicate item in protected branch/tag dropdown
+merge_request:
+author:
+type: fixed

spec/javascripts/create_item_dropdown_spec.js

+import CreateItemDropdown from '~/create_item_dropdown';
+
+const DROPDOWN_ITEM_DATA = [{
+  title: 'one',
+  id: 'one',
+  text: 'one',
+}, {
+  title: 'two',
+  id: 'two',
+  text: 'two',
+}, {
+  title: 'three',
+  id: 'three',
+  text: 'three',
+}];
+
+describe('CreateItemDropdown', () => {
+  preloadFixtures('static/create_item_dropdown.html.raw');
+
+  let $wrapperEl;
+
+  beforeEach(() => {
+    loadFixtures('static/create_item_dropdown.html.raw');
+    $wrapperEl = $('.js-create-item-dropdown-fixture-root');
+
+    // eslint-disable-next-line no-new
+    new CreateItemDropdown({
+      $dropdown: $wrapperEl.find('.js-dropdown-menu-toggle'),
+      defaultToggleLabel: 'All variables',
+      fieldName: 'variable[environment]',
+      getData: (term, callback) => {
+        callback(DROPDOWN_ITEM_DATA);
+      },
+    });
+  });
+
+  afterEach(() => {
+    $wrapperEl.remove();
+  });
+
+  it('should have a dropdown item for each piece of data', () => {
+    // Get the data in the dropdown
+    $('.js-dropdown-menu-toggle').click();
+
+    const $itemEls = $wrapperEl.find('.js-dropdown-content a');
+    expect($itemEls.length).toEqual(DROPDOWN_ITEM_DATA.length);
+  });
+
+  describe('created items', () => {
+    const NEW_ITEM_TEXT = 'foobarbaz';
+
+    function createItemAndClearInput(text) {
+      // Filter for the new item
+      $wrapperEl.find('.dropdown-input-field')
+        .val(text)
+        .trigger('input');
+
+      // Create the new item
+      const $createButton = $wrapperEl.find('.js-dropdown-create-new-item');
+      $createButton.click();
+
+      // Clear out the filter
+      $wrapperEl.find('.dropdown-input-field')
+        .val('')
+        .trigger('input');
+    }
+
+    beforeEach(() => {
+      // Open the dropdown
+      $('.js-dropdown-menu-toggle').click();
+
+      // Filter for the new item
+      $wrapperEl.find('.dropdown-input-field')
+        .val(NEW_ITEM_TEXT)
+        .trigger('input');
+    });
+
+    it('create new item button should include the filter text', () => {
+      expect($wrapperEl.find('.js-dropdown-create-new-item code').text()).toEqual(NEW_ITEM_TEXT);
+    });
+
+    it('should update the dropdown with the newly created item', () => {
+      // Create the new item
+      const $createButton = $wrapperEl.find('.js-dropdown-create-new-item');
+      $createButton.click();
+
+      expect($wrapperEl.find('.dropdown-toggle-text').text()).toEqual(NEW_ITEM_TEXT);
+      expect($wrapperEl.find('input[name="variable[environment]"]').val()).toEqual(NEW_ITEM_TEXT);
+    });
+
+    it('should include newly created item in dropdown list', () => {
+      createItemAndClearInput(NEW_ITEM_TEXT);
+
+      const $itemEls = $wrapperEl.find('.js-dropdown-content a');
+      expect($itemEls.length).toEqual(1 + DROPDOWN_ITEM_DATA.length);
+      expect($($itemEls.get(DROPDOWN_ITEM_DATA.length)).text()).toEqual(NEW_ITEM_TEXT);
+    });
+
+    it('should not duplicate an item when trying to create an existing item', () => {
+      createItemAndClearInput(DROPDOWN_ITEM_DATA[0].text);
+
+      const $itemEls = $wrapperEl.find('.js-dropdown-content a');
+      expect($itemEls.length).toEqual(DROPDOWN_ITEM_DATA.length);
+    });
+  });
+});

spec/javascripts/fixtures/create_item_dropdown.html.haml

+.js-create-item-dropdown-fixture-root
+  %input{ name: 'variable[environment]', type: 'hidden' }
+  = dropdown_tag('some label',
+                   options: { toggle_class: 'js-dropdown-menu-toggle',
+                              content_class: 'js-dropdown-content',
+                              filter: true,
+                              dropdown_class: "dropdown-menu-selectable",
+                              footer_content: true }) do
+    %ul.dropdown-footer-list
+      %li
+        %button{ class: "dropdown-create-new-item-button js-dropdown-create-new-item" }
+          Create wildcard
+          %code