diff --git a/src/streamer/parse/parse.py b/src/streamer/parse/parse.py
index a4c8421..4a8258f 100644
--- a/src/streamer/parse/parse.py
+++ b/src/streamer/parse/parse.py
@@ -20,8 +20,8 @@ def get_line_number(block_token: BlockToken) -> int:
 
 
 def build_shard(
-    start_line,
-    end_line,
+    start_line: int,
+    end_line: int,
     markers: list[str] = [],
     tags: list[str] = [],
     children: list[Shard] = [],
diff --git a/test/parse/test_attach_markdown.py b/test/parse/test_attach_markdown.py
new file mode 100644
index 0000000..21f8a1b
--- /dev/null
+++ b/test/parse/test_attach_markdown.py
@@ -0,0 +1,76 @@
+from faker import Faker
+
+from streamer.parse import Shard, StreamFile
+from streamer.parse.attach_markdown import (
+    ShardWithMarkdown,
+    StreamFileWithMarkdown,
+    attach_markdown,
+)
+
+fake = Faker()
+
+
+class TestAttachMarkdown:
+    file_name: str = fake.file_name(extension="md")
+
+    def test_attach_markdown_with_shard(self):
+        markdown_text = "Hello World\n\nThis is a test."
+        shard = Shard(start_line=1, end_line=3)
+        stream_file = StreamFile(filename=self.file_name, shard=shard)
+
+        result = attach_markdown(stream_file, markdown_text)
+
+        assert result == StreamFileWithMarkdown(
+            filename=self.file_name,
+            shard=ShardWithMarkdown(
+                start_line=1,
+                end_line=3,
+                markdown_content=markdown_text,
+                markers=[],
+                tags=[],
+                children=[],
+            ),
+        )
+
+    def test_attach_markdown_without_shard(self):
+        stream_file = StreamFile(filename=self.file_name, shard=None)
+
+        result = attach_markdown(stream_file, "Some markdown text")
+
+        assert result == StreamFileWithMarkdown(filename=self.file_name, shard=None)
+
+    def test_attach_markdown_with_nested_shards(self):
+        markdown_text = "Header\n\n@Marker1 Content 1\n\n@Marker2 Content 2"
+        shard = Shard(
+            start_line=1,
+            end_line=5,
+            children=[
+                Shard(markers=["Marker1"], start_line=3, end_line=3),
+                Shard(markers=["Marker2"], start_line=5, end_line=5),
+            ],
+        )
+        stream_file = StreamFile(filename=self.file_name, shard=shard)
+
+        result = attach_markdown(stream_file, markdown_text)
+
+        assert result.filename == self.file_name
+        assert result.shard is not None
+        assert result.shard.start_line == 1
+        assert result.shard.end_line == 5
+        assert (
+            result.shard.markdown_content
+            == "Header\n\n@Marker1 Content 1\n\n@Marker2 Content 2"
+        )
+        assert len(result.shard.children) == 2
+
+        # Check first child
+        assert result.shard.children[0].markers == ["Marker1"]
+        assert result.shard.children[0].start_line == 3
+        assert result.shard.children[0].end_line == 3
+        assert result.shard.children[0].markdown_content == "@Marker1 Content 1"
+
+        # Check second child
+        assert result.shard.children[1].markers == ["Marker2"]
+        assert result.shard.children[1].start_line == 5
+        assert result.shard.children[1].end_line == 5
+        assert result.shard.children[1].markdown_content == "@Marker2 Content 2"
diff --git a/test/test_parse.py b/test/parse/test_parse.py
similarity index 99%
rename from test/test_parse.py
rename to test/parse/test_parse.py
index e9c27ba..0a71671 100644
--- a/test/test_parse.py
+++ b/test/parse/test_parse.py
@@ -1,6 +1,7 @@
-from streamer.parse import StreamFile, parse_markdown_file, Shard
 from faker import Faker
 
+from streamer.parse import Shard, StreamFile, parse_markdown_file
+
 fake = Faker()