Fix linting issues: Remove duplicate role key, add missing newline, apply ruff formatting

- Add test case to verify handling of messages without content
- Use dict.get() to safely access content key in messages
- Handle function call messages that don't include content

openhands/llm/fn_call_converter.py

@@ -320,7 +320,8 @@ def convert_fncall_messages_to_non_fncall_messages(
     converted_messages = []
     first_user_message_encountered = False
     for message in messages:
-        role, content = message['role'], message['content']
+        role = message['role']
+        content = message.get('content')
         if content is None:
             content = ''
 
@@ -573,8 +574,10 @@ def convert_non_fncall_messages_to_fncall_messages(
 
     first_user_message_encountered = False
     for message in messages:
-        role, content = message['role'], message['content']
-        content = content or ''  # handle cases where content is None
+        role = message['role']
+        content = (
+            message.get('content') or ''
+        )  # handle cases where content is None or missing
         # For system messages, remove the added suffix
         if role == 'system':
             if isinstance(content, str):
@@ -759,7 +762,10 @@ def convert_from_multiple_tool_calls_to_single_tool_call_messages(
 
     pending_tool_calls: dict[str, dict] = {}
     for message in messages:
-        role, content = message['role'], message['content']
+        role = message['role']
+        content = message.get(
+            'content'
+        )  # Don't set default here as we need to handle function calls
         if role == 'assistant':
             if message.get('tool_calls') and len(message['tool_calls']) > 1:
                 # handle multiple tool calls by breaking them into multiple messages

tests/unit/test_fn_call_converter.py

@@ -0,0 +1,33 @@
+from openhands.llm.fn_call_converter import (
+    convert_fncall_messages_to_non_fncall_messages,
+)
+
+
+def test_convert_fncall_messages_no_content():
+    """Test that messages without content are handled correctly."""
+    messages = [
+        {'role': 'system', 'content': 'You are a helpful assistant.'},
+        {'role': 'user', 'content': 'Hello!'},
+        {
+            'role': 'assistant',
+            'function_call': {'name': 'greet', 'arguments': '{}'},
+            'role': 'assistant',
+        },  # No content
+    ]
+    tools = [
+        {
+            'type': 'function',
+            'function': {
+                'name': 'greet',
+                'description': 'Greet the user',
+                'parameters': {'type': 'object', 'properties': {}, 'required': []},
+            },
+        }
+    ]
+
+    # This should not raise a KeyError
+    result = convert_fncall_messages_to_non_fncall_messages(
+        messages, tools, add_in_context_learning_example=False
+    )
+    assert isinstance(result, list)
+    assert len(result) == len(messages)