test(cicd): cover message chunking boundaries

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

Author: anxkhn

tests/integrations/github/cicd/test_github_controller.py

@@ -917,15 +917,32 @@ def test_forward_only_config_falls_back_to_plan_config(
     assert controller.forward_only_plan is False
 
 
-def test_chunk_up_api_message_preserves_multibyte_chars(
+def test_chunk_up_api_message_preserves_ascii_behavior(
     github_client, make_event_issue_comment, make_controller
 ):
     controller = make_controller(make_event_issue_comment("created", "test"), github_client)
 
+    max_bytes = controller.MAX_BYTE_LENGTH
+    message = ("a" * max_bytes) + ("b" * max_bytes) + "c"
+
+    assert controller._chunk_up_api_message("") == []
+    assert controller._chunk_up_api_message(message) == [
+        "a" * max_bytes,
+        "b" * max_bytes,
+        "c",
+    ]
+
+
+@pytest.mark.parametrize("multibyte_char", ["🙂", "界"])
+def test_chunk_up_api_message_preserves_multibyte_chars(
+    github_client, make_event_issue_comment, make_controller, multibyte_char
+):
+    controller = make_controller(make_event_issue_comment("created", "test"), github_client)
+
     max_bytes = controller.MAX_BYTE_LENGTH
     # Place a multibyte character exactly on the byte boundary between two chunks so
     # that byte-oriented slicing would bisect its UTF-8 encoding and drop it.
-    message = ("a" * (max_bytes - 1)) + "é" + ("b" * max_bytes)
+    message = ("a" * (max_bytes - 1)) + multibyte_char + "b"
     assert len(message.encode("utf-8")) > max_bytes
 
     chunks = controller._chunk_up_api_message(message)