Fix: Do not convert URLs in Markdown to auto links

Auto links (<http://example.com>) are rendered as JSX tags, which results in an error.

Close #793

loaders/utils/__tests__/noAutoLinkRemarkPlugin.spec.js

@@ -0,0 +1,20 @@
+import remark from 'remark';
+import noAutoLink from '../noAutoLinkRemarkPlugin';
+
+const transform = markdown =>
+	remark()
+		.use(noAutoLink)
+		.processSync(markdown)
+		.toString();
+
+it('should not convert URLs to auto links', () => {
+	const markdown = 'http://example.com';
+	const result = transform(markdown);
+	expect(result.trim()).toBe('[http://example.com](http://example.com "http://example.com")');
+});
+
+it('should keep full inks as is', () => {
+	const markdown = '[Pizza](http://example.com)';
+	const result = transform(markdown);
+	expect(result.trim()).toBe(markdown);
+});

loaders/utils/highlightCodeInMarkdown.js

@@ -1,6 +1,7 @@
 const remark = require('remark');
 const visit = require('unist-util-visit');
 const highlightCode = require('./highlightCode');
+const noAutoLink = require('./noAutoLinkRemarkPlugin');
 
 function highlight() {
 	return ast => {
@@ -19,6 +20,7 @@ function highlight() {
 module.exports = function highlightCodeInMarkdown(markdown) {
 	return remark()
 		.use(highlight)
+		.use(noAutoLink)
 		.processSync(markdown)
 		.toString();
 };

loaders/utils/noAutoLinkRemarkPlugin.js

@@ -0,0 +1,30 @@
+const visit = require('unist-util-visit');
+
+// Return a Remark AST link node's link text
+const getLinkValue = node =>
+	node.children.reduce((value, child) => {
+		if (child.type === 'text') {
+			value += child.value;
+		}
+		return value;
+	}, '');
+
+/**
+ * Prevent printing URLs as auto links (<http://example.com>).
+ * Remark prints all links without a text as auto links, so we're adding a URL
+ * as a title. It has an unfortunate side effect: a link has a title of
+ * "http&#x3A;//..."
+ *
+ * @return {Object}
+ */
+module.exports = function noAutoLinkRemarkPlugin() {
+	return ast => {
+		visit(ast, 'link', node => {
+			const value = getLinkValue(node);
+
+			if (value === node.url) {
+				node.title = node.url;
+			}
+		});
+	};
+};