test(pandoc-partition): cover a fence closed by an indented marker

Distinct from the indented-open case already covered: opening fence
at column 0, closing marker indented, followed by a real heading.
Confirms the indented fence-close fix also resolves the case where a
heading after such a fence would otherwise never be reached.

Author: cderv

tests/unit/pandoc-partition.test.ts

@@ -161,6 +161,21 @@ unitTest(
   },
 );
 
+// deno-lint-ignore require-await
+unitTest(
+  "markdownWithExtractedHeading - closes a fence whose closing marker is indented, then extracts the following heading",
+  async () => {
+    const markdown = [
+      "```python",
+      "code",
+      "   ```",
+      "# Real Heading",
+    ].join("\n");
+    const result = markdownWithExtractedHeading(markdown);
+    assertEquals(result.headingText, "Real Heading");
+  },
+);
+
 // deno-lint-ignore require-await
 unitTest(
   "markdownWithExtractedHeading - extracts a setext-style heading",