Add fork suggestion component

Added a fork suggestion component

app/assets/javascripts/repository/components/fork_suggestion.vue

+<script>
+import { GlButton } from '@gitlab/ui';
+import { __ } from '~/locale';
+
+export default {
+  i18n: {
+    message: __(
+      'You can’t edit files directly in this project. Fork this project and submit a merge request with your changes.',
+    ),
+    fork: __('Fork'),
+    cancel: __('Cancel'),
+  },
+  components: {
+    GlButton,
+  },
+  props: {
+    forkPath: {
+      type: String,
+      required: true,
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="file-fork-suggestion">
+    <span class="file-fork-suggestion-note" data-testid="message">{{ $options.i18n.message }}</span>
+
+    <gl-button
+      class="gl-mr-3"
+      category="secondary"
+      variant="confirm"
+      :href="forkPath"
+      data-testid="fork"
+    >
+      {{ $options.i18n.fork }}
+    </gl-button>
+
+    <gl-button class="gl-mr-3" data-testid="cancel" @click="$emit('cancel')">
+      {{ $options.i18n.cancel }}
+    </gl-button>
+  </div>
+</template>

locale/gitlab.pot

@@ -38773,6 +38773,9 @@ msgstr ""
 msgid "You can’t %{tag_start}edit%{tag_end} files directly in this project. Fork this project and submit a merge request with your changes."
 msgstr ""
 
+msgid "You can’t edit files directly in this project. Fork this project and submit a merge request with your changes."
+msgstr ""
+
 msgid "You could not create a new trigger."
 msgstr ""
 

spec/frontend/repository/components/fork_suggestion_spec.js

+import { shallowMount } from '@vue/test-utils';
+import ForkSuggestion from '~/repository/components/fork_suggestion.vue';
+
+const DEFAULT_PROPS = { forkPath: 'some_file.js/fork' };
+
+describe('ForkSuggestion component', () => {
+  let wrapper;
+
+  const createComponent = () => {
+    wrapper = shallowMount(ForkSuggestion, {
+      propsData: { ...DEFAULT_PROPS },
+    });
+  };
+
+  beforeEach(() => createComponent());
+
+  afterEach(() => wrapper.destroy());
+
+  const findMessage = () => wrapper.find('[data-testid="message"]');
+  const findForkButton = () => wrapper.find('[data-testid="fork"]');
+  const findCancelButton = () => wrapper.find('[data-testid="cancel"]');
+
+  it('renders a message', () => {
+    expect(findMessage().exists()).toBe(true);
+    expect(findMessage().text()).toBe(
+      'You can’t edit files directly in this project. Fork this project and submit a merge request with your changes.',
+    );
+  });
+
+  it('renders component', () => {
+    const { forkPath } = DEFAULT_PROPS;
+
+    expect(wrapper.props()).toMatchObject({ forkPath });
+  });
+
+  it('renders a Fork button', () => {
+    expect(findForkButton().exists()).toBe(true);
+    expect(findForkButton().text()).toBe('Fork');
+    expect(findForkButton().attributes('href')).toBe(DEFAULT_PROPS.forkPath);
+  });
+
+  it('renders a Cancel button', () => {
+    expect(findCancelButton().exists()).toBe(true);
+    expect(findCancelButton().text()).toBe('Cancel');
+  });
+
+  it('emits a cancel event when Cancel button is clicked', () => {
+    findCancelButton().vm.$emit('click');
+
+    expect(wrapper.emitted('cancel')).toEqual([[]]);
+  });
+});