Fix support for spaces in class names

Related-to: 6fc783a.

Author: wooorm

lib/handlers/code.js

@@ -18,9 +18,12 @@ export function code(state, node) {
   const value = node.value ? node.value + '\n' : ''
   /** @type {Properties} */
   const properties = {}
+  // Someone can write `js python	ruby`.
+  const language = node.lang ? node.lang.split(/\s+/) : []
 
-  if (node.lang) {
-    properties.className = ['language-' + node.lang]
+  // GH/CM still drop the non-first languages.
+  if (language.length > 0) {
+    properties.className = ['language-' + language[0]]
   }
 
   // Create `<code>`.

test/code.js

@@ -34,6 +34,13 @@ test('code', async function (t) {
     }
   )
 
+  await t.test('should transform `lang` w/ spaces', async function () {
+    assert.deepEqual(
+      toHast({type: 'code', lang: 'js python\truby', value: 'echo()'}),
+      h('pre', [h('code', {className: ['language-js']}, 'echo()\n')])
+    )
+  })
+
   await t.test('should support `meta`', async function () {
     assert.deepEqual(
       toHast({type: 'code', lang: 'js', meta: 'echo', value: 'foxtrot()'}),