Add source viewer component

app/assets/javascripts/repository/components/blob_viewers/index.js

@@ -4,7 +4,10 @@ export const loadViewer = (type) => {
       return () => import(/* webpackChunkName: 'blob_empty_viewer' */ './empty_viewer.vue');
     case 'text':
       return gon.features.highlightJs
-        ? () => import(/* webpackChunkName: 'blob_text_viewer' */ './text_viewer.vue')
+        ? () =>
+            import(
+              /* webpackChunkName: 'blob_text_viewer' */ '~/vue_shared/components/source_viewer.vue'
+            )
         : null;
     case 'download':
       return () => import(/* webpackChunkName: 'blob_download_viewer' */ './download_viewer.vue');
@@ -23,8 +26,7 @@ export const viewerProps = (type, blob) => {
   return {
     text: {
       content: blob.rawTextBlob,
-      fileName: blob.name,
-      readOnly: true,
+      autoDetect: true, // We'll eventually disable autoDetect and pass the language explicitly to reduce the footprint (https://gitlab.com/gitlab-org/gitlab/-/issues/348145)
     },
     download: {
       fileName: blob.name,

app/assets/javascripts/repository/components/blob_viewers/text_viewer.vue

-<script>
-export default {
-  components: {
-    SourceEditor: () =>
-      import(/* webpackChunkName: 'SourceEditor' */ '~/vue_shared/components/source_editor.vue'),
-  },
-  props: {
-    content: {
-      type: String,
-      required: true,
-    },
-    fileName: {
-      type: String,
-      required: true,
-    },
-    readOnly: {
-      type: Boolean,
-      required: true,
-    },
-  },
-};
-</script>
-<template>
-  <source-editor :value="content" :file-name="fileName" :editor-options="{ readOnly }" />
-</template>

app/assets/javascripts/vue_shared/components/line_numbers.vue

+<script>
+import { GlIcon, GlLink } from '@gitlab/ui';
+
+export default {
+  components: {
+    GlIcon,
+    GlLink,
+  },
+  props: {
+    lines: {
+      type: Number,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      currentlyHighlightedLine: null,
+    };
+  },
+  mounted() {
+    this.scrollToLine();
+  },
+  methods: {
+    scrollToLine(hash = window.location.hash) {
+      const lineToHighlight = hash && this.$el.querySelector(hash);
+
+      if (!lineToHighlight) {
+        return;
+      }
+
+      if (this.currentlyHighlightedLine) {
+        this.currentlyHighlightedLine.classList.remove('hll');
+      }
+
+      lineToHighlight.classList.add('hll');
+      this.currentlyHighlightedLine = lineToHighlight;
+      lineToHighlight.scrollIntoView({ behavior: 'smooth', block: 'center' });
+    },
+  },
+};
+</script>
+<template>
+  <div class="line-numbers">
+    <gl-link
+      v-for="line in lines"
+      :id="`L${line}`"
+      :key="line"
+      class="diff-line-num"
+      :href="`#L${line}`"
+      :data-line-number="line"
+      @click="scrollToLine(`#L${line}`)"
+    >
+      <gl-icon :size="12" name="link" />
+      {{ line }}
+    </gl-link>
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/source_viewer.vue

+<script>
+import { GlSafeHtmlDirective } from '@gitlab/ui';
+import LineNumbers from '~/vue_shared/components/line_numbers.vue';
+
+export default {
+  components: {
+    LineNumbers,
+  },
+  directives: {
+    SafeHtml: GlSafeHtmlDirective,
+  },
+  props: {
+    content: {
+      type: String,
+      required: true,
+    },
+    language: {
+      type: String,
+      required: false,
+      default: 'plaintext',
+    },
+    autoDetect: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  data() {
+    return {
+      languageDefinition: null,
+      hljs: null,
+    };
+  },
+  computed: {
+    lineNumbers() {
+      return this.content.split('\n').length;
+    },
+    highlightedContent() {
+      let highlightedContent;
+
+      if (this.hljs) {
+        if (this.autoDetect) {
+          highlightedContent = this.hljs.highlightAuto(this.content).value;
+        } else if (this.languageDefinition) {
+          highlightedContent = this.hljs.highlight(this.content, { language: this.language }).value;
+        }
+      }
+
+      return highlightedContent;
+    },
+  },
+  async mounted() {
+    this.hljs = await this.loadHighlightJS();
+
+    if (!this.autoDetect) {
+      this.languageDefinition = await this.loadLanguage();
+    }
+  },
+  methods: {
+    loadHighlightJS() {
+      // With auto-detect enabled we load all common languages else we load only the core (smallest footprint)
+      return this.autoDetect ? import('highlight.js/lib/common') : import('highlight.js/lib/core');
+    },
+    async loadLanguage() {
+      let languageDefinition;
+
+      try {
+        languageDefinition = await import(`highlight.js/lib/languages/${this.language}`);
+        this.hljs.registerLanguage(this.language, languageDefinition.default);
+      } catch (message) {
+        this.$emit('error', message);
+      }
+
+      return languageDefinition;
+    },
+  },
+  userColorScheme: window.gon.user_color_scheme,
+};
+</script>
+<template>
+  <div class="file-content code" :class="$options.userColorScheme">
+    <line-numbers :lines="lineNumbers" />
+    <pre
+      class="code gl-pl-3!"
+    ><code v-safe-html="highlightedContent" class="gl-white-space-pre-wrap!"></code>
+    </pre>
+  </div>
+</template>

spec/frontend/repository/components/blob_content_viewer_spec.js

@@ -15,7 +15,7 @@ import ForkSuggestion from '~/repository/components/fork_suggestion.vue';
 import { loadViewer, viewerProps } from '~/repository/components/blob_viewers';
 import DownloadViewer from '~/repository/components/blob_viewers/download_viewer.vue';
 import EmptyViewer from '~/repository/components/blob_viewers/empty_viewer.vue';
-import TextViewer from '~/repository/components/blob_viewers/text_viewer.vue';
+import SourceViewer from '~/vue_shared/components/source_viewer.vue';
 import blobInfoQuery from '~/repository/queries/blob_info.query.graphql';
 import { redirectTo } from '~/lib/utils/url_utility';
 import { isLoggedIn } from '~/lib/utils/common_utils';
@@ -215,7 +215,7 @@ describe('Blob content viewer component', () => {
       viewer        | loadViewerReturnValue | viewerPropsReturnValue
       ${'empty'}    | ${EmptyViewer}        | ${{}}
       ${'download'} | ${DownloadViewer}     | ${{ filePath: '/some/file/path', fileName: 'test.js', fileSize: 100 }}
-      ${'text'}     | ${TextViewer}         | ${{ content: 'test', fileName: 'test.js', readOnly: true }}
+      ${'text'}     | ${SourceViewer}       | ${{ content: 'test', autoDetect: true }}
     `(
       'renders viewer component for $viewer files',
       async ({ viewer, loadViewerReturnValue, viewerPropsReturnValue }) => {

spec/frontend/repository/components/blob_viewers/text_viewer_spec.js

-import { shallowMount } from '@vue/test-utils';
-import waitForPromises from 'helpers/wait_for_promises';
-import TextViewer from '~/repository/components/blob_viewers/text_viewer.vue';
-import SourceEditor from '~/vue_shared/components/source_editor.vue';
-
-describe('Text Viewer', () => {
-  let wrapper;
-  const propsData = {
-    content: 'Some content',
-    fileName: 'file_name.js',
-    readOnly: true,
-  };
-
-  const createComponent = () => {
-    wrapper = shallowMount(TextViewer, { propsData });
-  };
-
-  const findEditor = () => wrapper.findComponent(SourceEditor);
-
-  it('renders a Source Editor component', async () => {
-    createComponent();
-
-    await waitForPromises();
-
-    expect(findEditor().exists()).toBe(true);
-    expect(findEditor().props('value')).toBe(propsData.content);
-    expect(findEditor().props('fileName')).toBe(propsData.fileName);
-    expect(findEditor().props('editorOptions')).toEqual({ readOnly: propsData.readOnly });
-  });
-});

spec/frontend/vue_shared/components/line_numbers_spec.js

+import { shallowMount } from '@vue/test-utils';
+import { GlIcon, GlLink } from '@gitlab/ui';
+import LineNumbers from '~/vue_shared/components/line_numbers.vue';
+
+describe('Line Numbers component', () => {
+  let wrapper;
+  const lines = 10;
+
+  const createComponent = () => {
+    wrapper = shallowMount(LineNumbers, { propsData: { lines } });
+  };
+
+  const findGlIcon = () => wrapper.findComponent(GlIcon);
+  const findLineNumbers = () => wrapper.findAllComponents(GlLink);
+  const findFirstLineNumber = () => findLineNumbers().at(0);
+  const findSecondLineNumber = () => findLineNumbers().at(1);
+
+  beforeEach(() => createComponent());
+
+  afterEach(() => wrapper.destroy());
+
+  describe('rendering', () => {
+    it('renders Line Numbers', () => {
+      expect(findLineNumbers().length).toBe(lines);
+      expect(findFirstLineNumber().attributes()).toMatchObject({
+        id: 'L1',
+        href: '#L1',
+      });
+    });
+
+    it('renders a link icon', () => {
+      expect(findGlIcon().props()).toMatchObject({
+        size: 12,
+        name: 'link',
+      });
+    });
+  });
+
+  describe('clicking a line number', () => {
+    let firstLineNumber;
+    let firstLineNumberElement;
+
+    beforeEach(() => {
+      firstLineNumber = findFirstLineNumber();
+      firstLineNumberElement = firstLineNumber.element;
+
+      jest.spyOn(firstLineNumberElement, 'scrollIntoView');
+      jest.spyOn(firstLineNumberElement.classList, 'add');
+      jest.spyOn(firstLineNumberElement.classList, 'remove');
+
+      firstLineNumber.vm.$emit('click');
+    });
+
+    it('adds the highlight (hll) class', () => {
+      expect(firstLineNumberElement.classList.add).toHaveBeenCalledWith('hll');
+    });
+
+    it('removes the highlight (hll) class from a previously highlighted line', () => {
+      findSecondLineNumber().vm.$emit('click');
+
+      expect(firstLineNumberElement.classList.remove).toHaveBeenCalledWith('hll');
+    });
+
+    it('scrolls the line into view', () => {
+      expect(firstLineNumberElement.scrollIntoView).toHaveBeenCalledWith({
+        behavior: 'smooth',
+        block: 'center',
+      });
+    });
+  });
+});

spec/frontend/vue_shared/components/source_viewer_spec.js

+import hljs from 'highlight.js/lib/core';
+import { shallowMountExtended } from 'helpers/vue_test_utils_helper';
+import SourceViewer from '~/vue_shared/components/source_viewer.vue';
+import LineNumbers from '~/vue_shared/components/line_numbers.vue';
+import waitForPromises from 'helpers/wait_for_promises';
+
+jest.mock('highlight.js/lib/core');
+
+describe('Source Viewer component', () => {
+  let wrapper;
+  const content = `// Some source code`;
+  const highlightedContent = `<span data-testid='test-highlighted'>${content}</span>`;
+  const language = 'javascript';
+
+  hljs.highlight.mockImplementation(() => ({ value: highlightedContent }));
+  hljs.highlightAuto.mockImplementation(() => ({ value: highlightedContent }));
+
+  const createComponent = async (props = {}) => {
+    wrapper = shallowMountExtended(SourceViewer, { propsData: { content, language, ...props } });
+    await waitForPromises();
+  };
+
+  const findLineNumbers = () => wrapper.findComponent(LineNumbers);
+  const findHighlightedContent = () => wrapper.findByTestId('test-highlighted');
+
+  beforeEach(() => createComponent());
+
+  afterEach(() => wrapper.destroy());
+
+  describe('highlight.js', () => {
+    it('registers the language definition', async () => {
+      const languageDefinition = await import(`highlight.js/lib/languages/${language}`);
+
+      expect(hljs.registerLanguage).toHaveBeenCalledWith(language, languageDefinition.default);
+    });
+
+    it('highlights the content', () => {
+      expect(hljs.highlight).toHaveBeenCalledWith(content, { language });
+    });
+
+    describe('auto-detect enabled', () => {
+      beforeEach(() => createComponent({ autoDetect: true }));
+
+      it('highlights the content with auto-detection', () => {
+        expect(hljs.highlightAuto).toHaveBeenCalledWith(content);
+      });
+    });
+  });
+
+  describe('rendering', () => {
+    it('renders Line Numbers', () => {
+      expect(findLineNumbers().props('lines')).toBe(1);
+    });
+
+    it('renders the highlighted content', () => {
+      expect(findHighlightedContent().exists()).toBe(true);
+    });
+  });
+});