Fix support for comments

Closes GH-61.
Closes GH-62.

Co-authored-by: Nauman Umer <[email protected]>

Author: wooorm

packages/rehype-katex/index.js

@@ -39,7 +39,7 @@ export default function rehypeKatex(options) {
         return
       }
 
-      const value = toText(element)
+      const value = toText(element, {whitespace: 'pre'})
 
       /** @type {string} */
       let result

packages/rehype-katex/package.json

@@ -40,7 +40,7 @@
   "dependencies": {
     "@types/hast": "^2.0.0",
     "@types/katex": "^0.11.0",
-    "hast-util-to-text": "^3.0.0",
+    "hast-util-to-text": "^3.1.0",
     "katex": "^0.13.0",
     "rehype-parse": "^8.0.0",
     "unified": "^10.0.0",

packages/rehype-katex/test.js

@@ -189,5 +189,29 @@ test('rehype-katex', (t) => {
     'should support `strict: ignore`'
   )
 
+  t.deepEqual(
+    unified()
+      .use(rehypeParse, {fragment: true})
+      .use(rehypeKatex, {errorColor: 'orange', strict: 'ignore'})
+      .use(rehypeStringify)
+      .processSync(
+        '<div class="math math-display">\\begin{split}\n  f(-2) &= \\sqrt{-2+4} \\\\\n  &= x % Test Comment\n\\end{split}</div>'
+      )
+      .toString(),
+    unified()
+      .use(rehypeParse, {fragment: true})
+      .use(rehypeStringify)
+      .processSync(
+        '<div class="math math-display">' +
+          katex.renderToString(
+            '\\begin{split}\n  f(-2) &= \\sqrt{-2+4} \\\\\n  &= x % Test Comment\n\\end{split}',
+            {displayMode: true}
+          ) +
+          '</div>'
+      )
+      .toString(),
+    'should support comments'
+  )
+
   t.end()
 })

packages/rehype-mathjax/lib/create-renderer.js

@@ -42,9 +42,11 @@ export function createRenderer(options, output) {
 
   return {
     render(node, options) {
-      // @ts-expect-error: assume mathml nodes can be handled by
-      // `hast-util-from-dom`.
-      const domNode = fromDom(doc.convert(toText(node), options))
+      const domNode = fromDom(
+        // @ts-expect-error: assume mathml nodes can be handled by
+        // `hast-util-from-dom`.
+        doc.convert(toText(node, {whitespace: 'pre'}), options)
+      )
       // @ts-expect-error: `fromDom` returns an element for a given element.
       node.children = [domNode]
     },

packages/rehype-mathjax/package.json

@@ -52,7 +52,7 @@
     "@types/mathjax": "^0.0.36",
     "@types/web": "^0.0.15",
     "hast-util-from-dom": "^4.0.0",
-    "hast-util-to-text": "^3.0.0",
+    "hast-util-to-text": "^3.1.0",
     "jsdom": "^16.0.0",
     "mathjax-full": "^3.0.0",
     "unified": "^10.0.0",