fix: inconsistency behavior parsing chat markup

feat: add more unit tests for chat module

python/promplate/prompt/chat.py

@@ -101,4 +101,4 @@ def parse_chat_markup(text: str) -> list[Message]:
         current_message["content"] = "\n".join(buffer)
         messages.append(current_message)
 
-    return messages or [{"role": "user", "content": text}]
+    return messages or [{"role": "user", "content": text.removesuffix("\n")}]

python/tests/test_chat.py

@@ -1,3 +1,5 @@
+from pytest import raises
+
 from promplate.prompt.chat import A, S, U, parse_chat_markup
 
 
@@ -16,3 +18,17 @@ def test_builder_names():
 def test_chat_markup():
     assert parse_chat_markup("hi") == [U > "hi"]
     assert parse_chat_markup("<| user name |>") == [U @ "name" > ""]
+    assert parse_chat_markup("123\n234\n\n345") == [U > "123\n234\n\n345"]
+    assert parse_chat_markup("<|user|>\n123\n<|assistant|>\n456") == [U > "123", A > "456"]
+
+
+def test_auto_trim_trailing_blank_line():
+    assert [U > "123"] == parse_chat_markup("123")
+    assert [U > "123"] == parse_chat_markup("123\n")
+    assert [U > "123"] == parse_chat_markup("<|user|>\n123")
+    assert [U > "123"] == parse_chat_markup("<|user|>\n123\n")
+
+
+def test_immutable_constants():
+    with raises(AssertionError):
+        A.content = "content"