Add support for lists of extensions

Author: wooorm

dev/lib/index.js

@@ -68,7 +68,7 @@
  * @property {NormalizedExtension} config
  *   Configuration.
  *
- * @typedef {{mdastExtensions?: Array.<Extension>}} FromMarkdownOptions
+ * @typedef {{mdastExtensions?: Array.<Extension|Array.<Extension>>}} FromMarkdownOptions
  * @typedef {ParseOptions & FromMarkdownOptions} Options
  */
 
@@ -1048,14 +1048,20 @@ function compiler(options = {}) {
 
 /**
  * @param {Extension} combined
- * @param {Array.<Extension>} extensions
+ * @param {Array.<Extension|Array.<Extension>>} extensions
  * @returns {Extension}
  */
 function configure(combined, extensions) {
   let index = -1
 
   while (++index < extensions.length) {
-    extension(combined, extensions[index])
+    const value = extensions[index]
+
+    if (Array.isArray(value)) {
+      configure(combined, value)
+    } else {
+      extension(combined, value)
+    }
   }
 
   return combined
@@ -1072,12 +1078,14 @@ function extension(combined, extension) {
 
   for (key in extension) {
     if (own.call(extension, key)) {
+      const list = key === 'canContainEols' || key === 'transforms'
       const maybe = own.call(combined, key) ? combined[key] : undefined
-      const left = maybe || (combined[key] = {})
+      /* c8 ignore next */
+      const left = maybe || (combined[key] = list ? [] : {})
       const right = extension[key]
 
       if (right) {
-        if (key === 'canContainEols' || key === 'transforms') {
+        if (list) {
           // @ts-expect-error: `left` is an array.
           combined[key] = [...left, ...right]
         } else {

test/index.js

@@ -127,6 +127,55 @@ test('mdast-util-from-markdown', (t) => {
     'should support extensions'
   )
 
+  t.deepEqual(
+    fromMarkdown('a\nb', {
+      mdastExtensions: [
+        [
+          {
+            enter: {
+              lineEnding(token) {
+                this.enter({type: 'break'}, token)
+              }
+            }
+          },
+          {
+            exit: {
+              lineEnding(token) {
+                this.exit(token)
+              }
+            }
+          }
+        ]
+      ]
+    }).children[0].children,
+    [
+      {
+        type: 'text',
+        value: 'a',
+        position: {
+          start: {line: 1, column: 1, offset: 0},
+          end: {line: 1, column: 2, offset: 1}
+        }
+      },
+      {
+        type: 'break',
+        position: {
+          start: {line: 1, column: 2, offset: 1},
+          end: {line: 2, column: 1, offset: 2}
+        }
+      },
+      {
+        type: 'text',
+        value: 'b',
+        position: {
+          start: {line: 2, column: 1, offset: 2},
+          end: {line: 2, column: 2, offset: 3}
+        }
+      }
+    ],
+    'should support multiple extensions'
+  )
+
   t.deepEqual(
     fromMarkdown('*a*', {
       mdastExtensions: [