Fix to create empty cells for nest tables

While tables in tables have no nice mdast representation, their
previous behavior was significantly broken, and this commit improves
that.

Closes GH-65.

Author: wooorm

lib/handlers/table.js

@@ -12,7 +12,9 @@
  */
 
 import {convertElement} from 'hast-util-is-element'
-import {visit} from 'unist-util-visit'
+import {toText} from 'hast-util-to-text'
+import {visit, SKIP} from 'unist-util-visit'
+import {wrapText} from '../util/wrap-text.js'
 import {all} from '../all.js'
 
 const thead = convertElement('thead')
@@ -24,6 +26,12 @@ const cell = convertElement(['th', 'td'])
  * @param {Element} node
  */
 export function table(h, node) {
+  if (h.inTable) {
+    return h(node, 'text', wrapText(h, toText(node)))
+  }
+
+  h.inTable = true
+
   const {headless, align} = inspect(node)
   const rows = toRows(all(h, node), headless)
   let columns = 1
@@ -91,6 +99,8 @@ export function table(h, node) {
     align.push(null)
   }
 
+  h.inTable = false
+
   return h(node, 'table', {align}, rows)
 }
 
@@ -108,6 +118,10 @@ function inspect(node) {
   const align = [null]
 
   visit(node, 'element', (child) => {
+    if (child.tagName === 'table' && node !== child) {
+      return SKIP
+    }
+
     // If there is a `thead`, assume there is a header row.
     if (cell(child) && child.properties) {
       if (!align[cellIndex]) {

lib/index.js

@@ -81,6 +81,7 @@ export function toMdast(tree, options = {}) {
     {
       nodeById: byId,
       baseFound: false,
+      inTable: false,
       wrapText: true,
       /** @type {string|null} */
       frozenBaseUrl: null,

lib/types.js

@@ -37,6 +37,7 @@
  * @property {boolean} baseFound
  * @property {string|null} frozenBaseUrl
  * @property {boolean} wrapText
+ * @property {boolean} inTable
  * @property {number} qNesting
  * @property {Object.<string, Handle>} handlers
  * @property {boolean|undefined} document

test/fixtures/table-in-table/index.html

@@ -0,0 +1,40 @@
+<table>
+  <tr>
+    <th>outer 1</th>
+    <th>outer 2</th>
+  </tr>
+  <tr>
+    <td>
+      <table>
+        <tr>
+          <td>inner a</td>
+          <td>inner b</td>
+          <td>inner c</td>
+        </tr>
+      </table>
+    </td>
+    <td>outer 3</td>
+  </tr>
+</table>
+
+<table>
+  <tr>
+    <td>
+      <table>
+        <tr>
+          <td>inner a</td>
+          <td>inner b</td>
+        </tr>
+        <tr>
+          <td>inner c</td>
+          <td>inner d</td>
+        </tr>
+        <tr>
+          <td>inner e</td>
+          <td>inner f</td>
+        </tr>
+      </table>
+    </td>
+    <td>outer 1</td>
+  </tr>
+</table>

test/fixtures/table-in-table/index.json

@@ -0,0 +1,3 @@
+{
+  "fragment": true
+}

test/fixtures/table-in-table/index.md

@@ -0,0 +1,7 @@
+| outer 1                 | outer 2 |
+| ----------------------- | ------- |
+| inner a	inner b	inner c | outer 3 |
+
+|                                                 |         |
+| ----------------------------------------------- | ------- |
+| inner a	inner b inner c	inner d inner e	inner f | outer 1 |