fix parsing role in prompt issue

src/promptflow-tools/promptflow/tools/common.py

@@ -98,8 +98,10 @@ def parse_function_role_prompt(function_str):
 
 def parse_chat(chat_str):
     # openai chat api only supports below roles.
-    separator = r"(?i)\n*(system|user|assistant|function)\s*:\s*\n"
-    chunks = re.split(separator, chat_str)
+    separator = r"(?i)\n+\s*(system|user|assistant|function)\s*:\s*\n"
+    # Add a newline at the beginning to ensure consistent formatting of role lines.
+    # extra new line is removed when appending to the chat list.
+    chunks = re.split(separator, '\n'+chat_str)
     chat_list = []
     for chunk in chunks:
         last_message = chat_list[-1] if len(chat_list) > 0 else None

src/promptflow-tools/tests/test_common.py

@@ -1,7 +1,7 @@
 import pytest
 
 from promptflow.tools.common import parse_function_role_prompt, ChatAPIInvalidFunctions, validate_functions, \
-    process_function_call
+    process_function_call, parse_chat
 
 
 class TestCommon:
@@ -50,3 +50,22 @@ def test_parse_function_role_prompt(self):
         result = parse_function_role_prompt(function_str)
         assert result[0] == "get_location"
         assert result[1] == 'Boston\nabc'
+
+    @pytest.mark.parametrize(
+        "chat_str, expected_result",
+        [
+            ("system:\nthis is my function:\ndef hello", [
+                {'role': 'system', 'content': 'this is my function:\ndef hello'}]),
+            (" \n system:\nthis is my function:\ndef hello", [
+                {'role': 'system', 'content': 'this is my function:\ndef hello'}]),
+            ("user:\nhi\nassistant:\nanswer\nfunction:\nname:\nn\ncontent:\nbla", [
+                {'role': 'user', 'content': 'hi'},
+                {'role': 'assistant', 'content': 'answer'},
+                {'role': 'function', 'name': 'n', 'content': 'bla'}]),
+            ("\nsystem:\nfirst\n\nsystem:\nsecond", [
+                {'role': 'system', 'content': 'first'}, {'role': 'system', 'content': 'second'}])
+        ]
+    )
+    def test_success_parse_role_prompt(self, chat_str, expected_result):
+        actual_result = parse_chat(chat_str)
+        assert actual_result == expected_result