Add latest changes from gitlab-org/gitlab@master

4 files changed, 104 insertions, 3 deletions

diff --git a/app/assets/javascripts/lib/gfm/constants.js b/app/assets/javascripts/lib/gfm/constants.js
new file mode 100644
index 00000000000..eaabeb2a767
--- /dev/null
+++ b/app/assets/javascripts/lib/gfm/constants.js
@@ -0,0 +1,10 @@
+export const TABLE_OF_CONTENTS_DOUBLE_BRACKET_OPEN_TOKEN = '[[';
+export const TABLE_OF_CONTENTS_DOUBLE_BRACKET_MIDDLE_TOKEN = 'TOC';
+export const TABLE_OF_CONTENTS_DOUBLE_BRACKET_CLOSE_TOKEN = ']]';
+export const TABLE_OF_CONTENTS_SINGLE_BRACKET_TOKEN = '[TOC]';
+
+export const MDAST_TEXT_NODE = 'text';
+export const MDAST_EMPHASIS_NODE = 'emphasis';
+export const MDAST_PARAGRAPH_NODE = 'paragraph';
+
+export const GLFM_TABLE_OF_CONTENTS_NODE = 'tableOfContents';
diff --git a/app/assets/javascripts/lib/gfm/glfm_extensions/table_of_contents.js b/app/assets/javascripts/lib/gfm/glfm_extensions/table_of_contents.js
new file mode 100644
index 00000000000..4d2484a657a
--- /dev/null
+++ b/app/assets/javascripts/lib/gfm/glfm_extensions/table_of_contents.js
@@ -0,0 +1,85 @@
+import { first, last } from 'lodash';
+import { u } from 'unist-builder';
+import { visitParents, SKIP, CONTINUE } from 'unist-util-visit-parents';
+import {
+  TABLE_OF_CONTENTS_DOUBLE_BRACKET_CLOSE_TOKEN,
+  TABLE_OF_CONTENTS_DOUBLE_BRACKET_MIDDLE_TOKEN,
+  TABLE_OF_CONTENTS_DOUBLE_BRACKET_OPEN_TOKEN,
+  TABLE_OF_CONTENTS_SINGLE_BRACKET_TOKEN,
+  MDAST_TEXT_NODE,
+  MDAST_EMPHASIS_NODE,
+  MDAST_PARAGRAPH_NODE,
+  GLFM_TABLE_OF_CONTENTS_NODE,
+} from '../constants';
+
+const isTOCTextNode = ({ type, value }) =>
+  type === MDAST_TEXT_NODE && value === TABLE_OF_CONTENTS_DOUBLE_BRACKET_MIDDLE_TOKEN;
+
+const isTOCEmphasisNode = ({ type, children }) =>
+  type === MDAST_EMPHASIS_NODE && children.length === 1 && isTOCTextNode(first(children));
+
+const isTOCDoubleSquareBracketOpenTokenTextNode = ({ type, value }) =>
+  type === MDAST_TEXT_NODE && value.trim() === TABLE_OF_CONTENTS_DOUBLE_BRACKET_OPEN_TOKEN;
+
+const isTOCDoubleSquareBracketCloseTokenTextNode = ({ type, value }) =>
+  type === MDAST_TEXT_NODE && value.trim() === TABLE_OF_CONTENTS_DOUBLE_BRACKET_CLOSE_TOKEN;
+
+/*
+ * Detects table of contents declaration with syntax [[_TOC_]]
+ */
+const isTableOfContentsDoubleSquareBracketSyntax = ({ children }) => {
+  if (children.length !== 3) {
+    return false;
+  }
+
+  const [firstChild, middleChild, lastChild] = children;
+
+  return (
+    isTOCDoubleSquareBracketOpenTokenTextNode(firstChild) &&
+    isTOCEmphasisNode(middleChild) &&
+    isTOCDoubleSquareBracketCloseTokenTextNode(lastChild)
+  );
+};
+
+/*
+ * Detects table of contents declaration with syntax [TOC]
+ */
+const isTableOfContentsSingleSquareBracketSyntax = ({ children }) => {
+  if (children.length !== 1) {
+    return false;
+  }
+
+  const [firstChild] = children;
+  const { type, value } = firstChild;
+
+  return type === MDAST_TEXT_NODE && value.trim() === TABLE_OF_CONTENTS_SINGLE_BRACKET_TOKEN;
+};
+
+const isTableOfContentsNode = (node) =>
+  node.type === MDAST_PARAGRAPH_NODE &&
+  (isTableOfContentsDoubleSquareBracketSyntax(node) ||
+    isTableOfContentsSingleSquareBracketSyntax(node));
+
+export default () => {
+  return (tree) => {
+    visitParents(tree, (node, ancestors) => {
+      const parent = last(ancestors);
+
+      if (!parent) {
+        return CONTINUE;
+      }
+
+      if (isTableOfContentsNode(node)) {
+        const index = parent.children.indexOf(node);
+
+        parent.children[index] = u(GLFM_TABLE_OF_CONTENTS_NODE, {
+          position: node.position,
+        });
+      }
+
+      return SKIP;
+    });
+
+    return tree;
+  };
+};
diff --git a/app/assets/javascripts/lib/gfm/index.js b/app/assets/javascripts/lib/gfm/index.js
index eaf653e9924..fad73f93c1a 100644
--- a/app/assets/javascripts/lib/gfm/index.js
+++ b/app/assets/javascripts/lib/gfm/index.js
@@ -6,6 +6,8 @@ import remarkFrontmatter from 'remark-frontmatter';
 import remarkGfm from 'remark-gfm';
 import remarkRehype, { all } from 'remark-rehype';
 import rehypeRaw from 'rehype-raw';
+import glfmTableOfContents from './glfm_extensions/table_of_contents';
+import * as glfmMdastToHastHandlers from './mdast_to_hast_handlers/glfm_mdast_to_hast_handlers';
 
 const skipFrontmatterHandler = (language) => (h, node) =>
   h(node.position, 'frontmatter', { language }, [{ type: 'text', value: node.value }]);
@@ -65,19 +67,22 @@ const skipRenderingHandlers = {
       all(h, node),
     );
   },
+  tableOfContents: (h, node) => h(node.position, 'tableOfContents'),
   toml: skipFrontmatterHandler('toml'),
   yaml: skipFrontmatterHandler('yaml'),
   json: skipFrontmatterHandler('json'),
 };
 
-const createParser = ({ skipRendering = [] }) => {
+const createParser = ({ skipRendering }) => {
   return unified()
     .use(remarkParse)
     .use(remarkGfm)
     .use(remarkFrontmatter, ['yaml', 'toml', { type: 'json', marker: ';' }])
+    .use(glfmTableOfContents)
     .use(remarkRehype, {
       allowDangerousHtml: true,
       handlers: {
+        ...glfmMdastToHastHandlers,
         ...pick(skipRenderingHandlers, skipRendering),
       },
     })
@@ -99,13 +104,13 @@ const compilerFactory = (renderer) =>
  * tree in any desired representation
  *
  * @param {String} params.markdown Markdown to parse
- * @param {(tree: MDast -> any)} params.renderer A function that accepts mdast
+ * @param {Function} params.renderer A function that accepts mdast
  * AST tree and returns an object of any type that represents the result of
  * rendering the tree. See the references below to for more information
  * about MDast.
  *
  * MDastTree documentation https://github.com/syntax-tree/mdast
- * @returns {Promise<any>} Returns a promise with the result of rendering
+ * @returns {Promise} Returns a promise with the result of rendering
  * the MDast tree
  */
 export const render = async ({ markdown, renderer, skipRendering = [] }) => {
diff --git a/app/assets/javascripts/lib/gfm/mdast_to_hast_handlers/glfm_mdast_to_hast_handlers.js b/app/assets/javascripts/lib/gfm/mdast_to_hast_handlers/glfm_mdast_to_hast_handlers.js
new file mode 100644
index 00000000000..91b09e69405
--- /dev/null
+++ b/app/assets/javascripts/lib/gfm/mdast_to_hast_handlers/glfm_mdast_to_hast_handlers.js
@@ -0,0 +1 @@
+export const tableOfContents = (h, node) => h(node.position, 'nav');