Add support for arbitrary indent when w/o codeIntended

Related-to: facebook/docusaurus#10305.

dev/lib/directive-container.js

@@ -197,12 +197,14 @@ function tokenizeDirectiveContainer(effects, ok, nok) {
    */
   function tokenizeClosingFence(effects, ok, nok) {
     let size = 0
-
+    assert(self.parser.constructs.disable.null, 'expected `disable.null`')
     return factorySpace(
       effects,
       closingPrefixAfter,
       types.linePrefix,
-      constants.tabSize
+      self.parser.constructs.disable.null.includes('codeIndented')
+        ? undefined
+        : constants.tabSize
     )
 
     /** @type {State} */

test/index.js

@@ -993,6 +993,20 @@ test('micromark-extension-directive (syntax, container)', async function (t) {
     }
   )
 
+  await t.test(
+    'should strip arbitrary length prefix from closing fence line (codeIndented disabled)',
+    async function () {
+      assert.equal(
+        micromark(':::x\nalpha.\n    :::\n\nbravo.', {
+          allowDangerousHtml: true,
+          extensions: [directive(), {disable: {null: ['codeIndented']}}],
+          htmlExtensions: [directiveHtml()]
+        }),
+        '<p>bravo.</p>'
+      )
+    }
+  )
+
   await t.test(
     'should support a block quote after a container',
     async function () {