Add support for inferring phrasing of embedded hast

Related-to: syntax-tree/unist#75.
Closes GH-74.

Reviewed-by: Titus Wormer <tituswormer@gmail.com>

Co-authored-by: Titus Wormer <tituswormer@gmail.com>

Author: triaeiou

lib/util/wrap.js

@@ -5,7 +5,23 @@
  */
 
 import extend from 'extend'
-import {phrasing} from 'mdast-util-phrasing'
+import {phrasing as hastPhrasing} from 'hast-util-phrasing'
+import {phrasing as mdastPhrasing} from 'mdast-util-phrasing'
+
+/**
+ * @param {MdastNode} node
+ * @returns {node is MdastPhrasingContent}
+ */
+function phrasing(node) {
+  return node.data && node.data.hName
+    ? hastPhrasing({
+        type: 'element',
+        tagName: node.data.hName,
+        properties: {},
+        children: []
+      })
+    : mdastPhrasing(node)
+}
 
 /**
  * @param {Array.<MdastNode>} nodes
@@ -80,7 +96,7 @@ function runs(nodes, onphrasing, onnonphrasing) {
 
     if (phrasing(node)) {
       if (!queue) queue = []
-      queue.push(node)
+      queue.push(/** @type {MdastPhrasingContent} */ (node))
     } else {
       if (queue) {
         result = result.concat(onphrasing(queue))

package.json

@@ -45,6 +45,7 @@
     "hast-util-is-element": "^2.0.0",
     "hast-util-to-text": "^3.0.0",
     "mdast-util-phrasing": "^3.0.0",
+    "hast-util-phrasing": "^2.0.1",
     "mdast-util-to-string": "^3.0.0",
     "rehype-minify-whitespace": "^5.0.0",
     "trim-trailing-lines": "^2.0.0",

test/index.js

@@ -19,9 +19,36 @@ import remarkStringify from 'remark-stringify'
 import {assert} from 'mdast-util-assert'
 import {removePosition} from 'unist-util-remove-position'
 import {one, all, defaultHandlers, toMdast} from '../index.js'
+import {wrapNeeded} from '../lib/util/wrap.js'
 
 const fixtures = path.join('test', 'fixtures')
 
+test('custom nodes', (t) => {
+  t.deepEqual(
+    wrapNeeded([
+      {type: 'text', value: 'some '},
+      {
+        // @ts-expect-error - custom node type
+        type: 'superscript',
+        data: {hName: 'sup'},
+        children: [{type: 'text', value: 'test'}]
+      },
+      {type: 'text', value: ' text'}
+    ]),
+    wrapNeeded([
+      {type: 'text', value: 'some '},
+      {
+        type: 'emphasis',
+        children: [{type: 'text', value: 'test'}]
+      },
+      {type: 'text', value: ' text'}
+    ]),
+    'should support `node.data.hName` to infer phrasing'
+  )
+
+  t.end()
+})
+
 test('exports', (t) => {
   t.assert(one, 'should export `one`')