Updates based on PR feedback

Author: SamRemis

packages/smithy-http/src/smithy_http/aio/crt.py

@@ -341,10 +341,9 @@ async def _marshal_request(
         :py:class:`smithy_http.aio.HTTPRequest`"""
         headers_list = []
         if "host" not in request.fields:
-            host_header = request.destination.host
-            if port := request.destination.port:
-                host_header += f":{port}"
-            request.fields.set_field(Field(name="host", values=[host_header]))
+            request.fields.set_field(
+                Field(name="host", values=[request.destination.netloc])
+            )
 
         if "accept" not in request.fields:
             request.fields.set_field(Field(name="accept", values=["*/*"]))

packages/smithy-http/tests/unit/aio/test_crt.py

@@ -36,18 +36,25 @@ async def test_client_marshal_request() -> None:
     assert crt_request.path == "/path?key1=value1&key2=value2"  # type: ignore
 
 
-async def test_port_included_in_host_header() -> None:
+@pytest.mark.parametrize(
+    "host,expected",
+    [
+        ("example.com", "example.com:8443"),
+        ("2001:db8::1", "[2001:db8::1]:8443"),
+    ],
+)
+async def test_port_included_in_host_header(host: str, expected: str) -> None:
     client = AWSCRTHTTPClient()
     request = HTTPRequest(
         method="GET",
         destination=URI(
-            host="example.com", path="/path", query="key1=value1&key2=value2", port=8443
+            host=host, path="/path", query="key1=value1&key2=value2", port=8443
         ),
         body=BytesIO(),
         fields=Fields(),
     )
     crt_request, _ = await client._marshal_request(request)  # type: ignore
-    assert crt_request.headers.get("host") == "example.com:8443"  # type: ignore
+    assert crt_request.headers.get("host") == expected  # type: ignore
 
 
 def test_stream_write() -> None: