Add IssuableEditForm component

Adds IssuableEditForm component to use with
Issuable Show app.

app/assets/javascripts/issuable_show/components/issuable_edit_form.vue

+<script>
+import $ from 'jquery';
+import { GlForm, GlFormGroup, GlFormInput } from '@gitlab/ui';
+
+import Autosave from '~/autosave';
+import MarkdownField from '~/vue_shared/components/markdown/field.vue';
+
+import eventHub from '../event_hub';
+
+export default {
+  components: {
+    GlForm,
+    GlFormGroup,
+    GlFormInput,
+    MarkdownField,
+  },
+  props: {
+    issuable: {
+      type: Object,
+      required: true,
+    },
+    enableAutocomplete: {
+      type: Boolean,
+      required: true,
+    },
+    descriptionPreviewPath: {
+      type: String,
+      required: true,
+    },
+    descriptionHelpPath: {
+      type: String,
+      required: true,
+    },
+  },
+  data() {
+    const { title, description } = this.issuable;
+
+    return {
+      title,
+      description,
+    };
+  },
+  created() {
+    eventHub.$on('update.issuable', this.resetAutosave);
+    eventHub.$on('close.form', this.resetAutosave);
+  },
+  mounted() {
+    this.initAutosave();
+  },
+  beforeDestroy() {
+    eventHub.$off('update.issuable', this.resetAutosave);
+    eventHub.$off('close.form', this.resetAutosave);
+  },
+  methods: {
+    initAutosave() {
+      const { titleInput, descriptionInput } = this.$refs;
+
+      if (!titleInput || !descriptionInput) return;
+
+      this.autosaveTitle = new Autosave($(titleInput.$el), [
+        document.location.pathname,
+        document.location.search,
+        'title',
+      ]);
+
+      this.autosaveDescription = new Autosave($(descriptionInput.$el), [
+        document.location.pathname,
+        document.location.search,
+        'description',
+      ]);
+    },
+    resetAutosave() {
+      this.autosaveTitle.reset();
+      this.autosaveDescription.reset();
+    },
+  },
+};
+</script>
+
+<template>
+  <gl-form>
+    <gl-form-group
+      data-testid="title"
+      :label="__('Title')"
+      :label-sr-only="true"
+      label-for="issuable-title"
+      class="col-12"
+    >
+      <gl-form-input
+        id="issuable-title"
+        ref="titleInput"
+        v-model.trim="title"
+        :placeholder="__('Title')"
+        :aria-label="__('Title')"
+        :autofocus="true"
+        class="qa-title-input"
+      />
+    </gl-form-group>
+    <gl-form-group
+      data-testid="description"
+      :label="__('Description')"
+      :label-sr-only="true"
+      label-for="issuable-description"
+      class="col-12 common-note-form"
+    >
+      <markdown-field
+        :markdown-preview-path="descriptionPreviewPath"
+        :markdown-docs-path="descriptionHelpPath"
+        :enable-autocomplete="enableAutocomplete"
+        :textarea-value="description"
+      >
+        <template #textarea>
+          <textarea
+            id="issuable-description"
+            ref="descriptionInput"
+            v-model="description"
+            :data-supports-quick-actions="enableAutocomplete"
+            :aria-label="__('Description')"
+            :placeholder="__('Write a comment or drag your files here…')"
+            class="note-textarea js-gfm-input js-autosize markdown-area
+          qa-description-textarea"
+            dir="auto"
+          ></textarea>
+        </template>
+      </markdown-field>
+    </gl-form-group>
+    <div data-testid="actions" class="col-12 gl-mt-3 gl-mb-3 clearfix">
+      <slot
+        name="edit-form-actions"
+        :issuable-title="title"
+        :issuable-description="description"
+      ></slot>
+    </div>
+  </gl-form>
+</template>

app/assets/javascripts/issuable_show/event_hub.js

+import createEventHub from '~/helpers/event_hub_factory';
+
+export default createEventHub();

spec/frontend/issuable_show/components/issuable_edit_form_spec.js

+import { shallowMount } from '@vue/test-utils';
+import { GlFormInput } from '@gitlab/ui';
+import MarkdownField from '~/vue_shared/components/markdown/field.vue';
+
+import IssuableEditForm from '~/issuable_show/components/issuable_edit_form.vue';
+import IssuableEventHub from '~/issuable_show/event_hub';
+
+import { mockIssuableShowProps, mockIssuable } from '../mock_data';
+
+const issuableEditFormProps = {
+  issuable: mockIssuable,
+  ...mockIssuableShowProps,
+};
+
+const createComponent = ({ propsData = issuableEditFormProps } = {}) =>
+  shallowMount(IssuableEditForm, {
+    propsData,
+    stubs: {
+      MarkdownField,
+    },
+    slots: {
+      'edit-form-actions': `
+        <button class="js-save">Save changes</button>
+        <button class="js-cancel">Cancel</button>
+      `,
+    },
+  });
+
+describe('IssuableEditForm', () => {
+  let wrapper;
+  const assertEvent = eventSpy => {
+    expect(eventSpy).toHaveBeenNthCalledWith(1, 'update.issuable', expect.any(Function));
+    expect(eventSpy).toHaveBeenNthCalledWith(2, 'close.form', expect.any(Function));
+  };
+
+  beforeEach(() => {
+    wrapper = createComponent();
+  });
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  describe('created', () => {
+    it('binds `update.issuable` and `close.form` event listeners', () => {
+      const eventOnSpy = jest.spyOn(IssuableEventHub, '$on');
+      const wrapperTemp = createComponent();
+
+      assertEvent(eventOnSpy);
+
+      wrapperTemp.destroy();
+    });
+  });
+
+  describe('beforeDestroy', () => {
+    it('unbinds `update.issuable` and `close.form` event listeners', () => {
+      const wrapperTemp = createComponent();
+      const eventOffSpy = jest.spyOn(IssuableEventHub, '$off');
+
+      wrapperTemp.destroy();
+
+      assertEvent(eventOffSpy);
+    });
+  });
+
+  describe('methods', () => {
+    describe('initAutosave', () => {
+      it('initializes `autosaveTitle` and `autosaveDescription` props', () => {
+        expect(wrapper.vm.autosaveTitle).toBeDefined();
+        expect(wrapper.vm.autosaveDescription).toBeDefined();
+      });
+    });
+
+    describe('resetAutosave', () => {
+      it('calls `reset` on `autosaveTitle` and `autosaveDescription` props', () => {
+        jest.spyOn(wrapper.vm.autosaveTitle, 'reset').mockImplementation(jest.fn);
+        jest.spyOn(wrapper.vm.autosaveDescription, 'reset').mockImplementation(jest.fn);
+
+        wrapper.vm.resetAutosave();
+
+        expect(wrapper.vm.autosaveTitle.reset).toHaveBeenCalled();
+        expect(wrapper.vm.autosaveDescription.reset).toHaveBeenCalled();
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('renders title input field', () => {
+      const titleInputEl = wrapper.find('[data-testid="title"]');
+
+      expect(titleInputEl.exists()).toBe(true);
+      expect(titleInputEl.find(GlFormInput).attributes()).toMatchObject({
+        'aria-label': 'Title',
+        placeholder: 'Title',
+      });
+    });
+
+    it('renders description textarea field', () => {
+      const descriptionEl = wrapper.find('[data-testid="description"]');
+
+      expect(descriptionEl.exists()).toBe(true);
+      expect(descriptionEl.find(MarkdownField).props()).toMatchObject({
+        markdownPreviewPath: issuableEditFormProps.descriptionPreviewPath,
+        markdownDocsPath: issuableEditFormProps.descriptionHelpPath,
+        enableAutocomplete: issuableEditFormProps.enableAutocomplete,
+        textareaValue: mockIssuable.description,
+      });
+      expect(descriptionEl.find('textarea').attributes()).toMatchObject({
+        'data-supports-quick-actions': 'true',
+        'aria-label': 'Description',
+        placeholder: 'Write a comment or drag your files here…',
+      });
+    });
+
+    it('renders form actions', () => {
+      const actionsEl = wrapper.find('[data-testid="actions"]');
+
+      expect(actionsEl.find('button.js-save').exists()).toBe(true);
+      expect(actionsEl.find('button.js-cancel').exists()).toBe(true);
+    });
+  });
+});