Disable create list button after clicked once

Changelog: changed

app/assets/javascripts/boards/components/board_add_new_column_trigger.vue

 <script>
-import { GlButton } from '@gitlab/ui';
-import { mapActions } from 'vuex';
+import { GlButton, GlTooltipDirective } from '@gitlab/ui';
+import { mapActions, mapState } from 'vuex';
+import { __ } from '~/locale';
 import Tracking from '~/tracking';
 
 export default {
   components: {
     GlButton,
   },
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
   mixins: [Tracking.mixin()],
+  computed: {
+    ...mapState({ isNewListShowing: ({ addColumnForm }) => addColumnForm.visible }),
+    tooltip() {
+      return this.isNewListShowing ? __('The list creation wizard is already open') : '';
+    },
+  },
   methods: {
     ...mapActions(['setAddColumnFormVisibility']),
     handleClick() {
@@ -19,7 +29,14 @@ export default {
 </script>
 
 <template>
-  <div class="gl-ml-3 gl-display-flex gl-align-items-center" data-testid="boards-create-list">
-    <gl-button variant="confirm" @click="handleClick">{{ __('Create list') }} </gl-button>
+  <div
+    v-gl-tooltip="tooltip"
+    :tabindex="isNewListShowing ? '0' : undefined"
+    class="gl-ml-3 gl-display-flex gl-align-items-center"
+    data-testid="boards-create-list"
+  >
+    <gl-button :disabled="isNewListShowing" variant="confirm" @click="handleClick"
+      >{{ __('Create list') }}
+    </gl-button>
   </div>
 </template>

locale/gitlab.pot

@@ -34029,6 +34029,9 @@ msgstr ""
 msgid "The license was successfully uploaded and will be active from %{starts_at}. You can see the details below."
 msgstr ""
 
+msgid "The list creation wizard is already open"
+msgstr ""
+
 msgid "The maximum file size allowed is %{size}."
 msgstr ""
 

spec/frontend/boards/components/board_add_new_column_trigger_spec.js

+import { GlButton } from '@gitlab/ui';
+import Vue from 'vue';
+import Vuex from 'vuex';
+import { mountExtended } from 'helpers/vue_test_utils_helper';
+import BoardAddNewColumnTrigger from '~/boards/components/board_add_new_column_trigger.vue';
+import { createStore } from '~/boards/stores';
+import { createMockDirective, getBinding } from 'helpers/vue_mock_directive';
+
+Vue.use(Vuex);
+
+describe('BoardAddNewColumnTrigger', () => {
+  let wrapper;
+
+  const findBoardsCreateList = () => wrapper.findByTestId('boards-create-list');
+  const findTooltipText = () => getBinding(findBoardsCreateList().element, 'gl-tooltip');
+
+  const mountComponent = () => {
+    wrapper = mountExtended(BoardAddNewColumnTrigger, {
+      directives: {
+        GlTooltip: createMockDirective(),
+      },
+      store: createStore(),
+    });
+  };
+
+  beforeEach(() => {
+    mountComponent();
+  });
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  describe('when button is active', () => {
+    it('does not show the tooltip', () => {
+      const tooltip = findTooltipText();
+
+      expect(tooltip.value).toBe('');
+    });
+
+    it('renders an enabled button', () => {
+      const button = wrapper.find(GlButton);
+
+      expect(button.props('disabled')).toBe(false);
+    });
+  });
+
+  describe('when button is disabled', () => {
+    it('shows the tooltip', async () => {
+      wrapper.find(GlButton).vm.$emit('click');
+
+      await wrapper.vm.$nextTick();
+
+      const tooltip = findTooltipText();
+
+      expect(tooltip.value).toBe('The list creation wizard is already open');
+    });
+  });
+});