Fix test to use anyio.run() pattern and add edge case tests

- Convert async test to use anyio.run() pattern consistent with other tests
- Remove unused CLIJSONDecodeError import
- Add tests for JSON with embedded newlines
- Add tests for multiple newlines between objects
- All tests passing

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/test_subprocess_buffering.py

@@ -5,9 +5,8 @@ from collections.abc import AsyncIterator
 from typing import Any
 from unittest.mock import AsyncMock, MagicMock
 
-import pytest
+import anyio
 
-from claude_code_sdk._errors import CLIJSONDecodeError
 from claude_code_sdk._internal.transport.subprocess_cli import SubprocessCLITransport
 from claude_code_sdk.types import ClaudeCodeOptions
 
@@ -33,47 +32,113 @@ class MockTextReceiveStream:
 class TestSubprocessBuffering:
     """Test subprocess transport handling of buffered output."""
 
-    @pytest.mark.asyncio
-    async def test_multiple_json_objects_on_single_line(self) -> None:
+    def test_multiple_json_objects_on_single_line(self) -> None:
         """Test parsing when multiple JSON objects are concatenated on a single line.
 
         In some environments, stdout buffering can cause multiple distinct JSON
         objects to be delivered as a single line with embedded newlines.
         """
-        # Two valid JSON objects separated by a newline character
-        json_obj1 = {"type": "message", "id": "msg1", "content": "First message"}
-        json_obj2 = {"type": "result", "id": "res1", "status": "completed"}
+        async def _test() -> None:
+            # Two valid JSON objects separated by a newline character
+            json_obj1 = {"type": "message", "id": "msg1", "content": "First message"}
+            json_obj2 = {"type": "result", "id": "res1", "status": "completed"}
 
-        # Simulate buffered output where both objects appear on one line
-        buffered_line = json.dumps(json_obj1) + '\n' + json.dumps(json_obj2)
+            # Simulate buffered output where both objects appear on one line
+            buffered_line = json.dumps(json_obj1) + '\n' + json.dumps(json_obj2)
 
-        # Create transport
-        transport = SubprocessCLITransport(
-            prompt="test",
-            options=ClaudeCodeOptions(),
-            cli_path="/usr/bin/claude"
-        )
+            # Create transport
+            transport = SubprocessCLITransport(
+                prompt="test",
+                options=ClaudeCodeOptions(),
+                cli_path="/usr/bin/claude"
+            )
 
-        # Mock the process and streams
-        mock_process = MagicMock()
-        mock_process.returncode = None
-        mock_process.wait = AsyncMock(return_value=None)
-        transport._process = mock_process
+            # Mock the process and streams
+            mock_process = MagicMock()
+            mock_process.returncode = None
+            mock_process.wait = AsyncMock(return_value=None)
+            transport._process = mock_process
 
-        # Create mock stream that returns the buffered line
-        transport._stdout_stream = MockTextReceiveStream([buffered_line])  # type: ignore[assignment]
-        transport._stderr_stream = MockTextReceiveStream([])  # type: ignore[assignment]
+            # Create mock stream that returns the buffered line
+            transport._stdout_stream = MockTextReceiveStream([buffered_line])  # type: ignore[assignment]
+            transport._stderr_stream = MockTextReceiveStream([])  # type: ignore[assignment]
 
-        # Collect all messages
-        messages: list[Any] = []
-        async for msg in transport.receive_messages():
-            messages.append(msg)
+            # Collect all messages
+            messages: list[Any] = []
+            async for msg in transport.receive_messages():
+                messages.append(msg)
 
-        # Verify both JSON objects were successfully parsed
-        assert len(messages) == 2
-        assert messages[0]["type"] == "message"
-        assert messages[0]["id"] == "msg1"
-        assert messages[0]["content"] == "First message"
-        assert messages[1]["type"] == "result"
-        assert messages[1]["id"] == "res1"
-        assert messages[1]["status"] == "completed"
+            # Verify both JSON objects were successfully parsed
+            assert len(messages) == 2
+            assert messages[0]["type"] == "message"
+            assert messages[0]["id"] == "msg1"
+            assert messages[0]["content"] == "First message"
+            assert messages[1]["type"] == "result"
+            assert messages[1]["id"] == "res1"
+            assert messages[1]["status"] == "completed"
+
+        anyio.run(_test)
+
+    def test_json_with_embedded_newlines(self) -> None:
+        """Test parsing JSON objects that contain newline characters in string values."""
+        async def _test() -> None:
+            # JSON objects with newlines in string values
+            json_obj1 = {"type": "message", "content": "Line 1\nLine 2\nLine 3"}
+            json_obj2 = {"type": "result", "data": "Some\nMultiline\nContent"}
+            
+            buffered_line = json.dumps(json_obj1) + '\n' + json.dumps(json_obj2)
+            
+            transport = SubprocessCLITransport(
+                prompt="test",
+                options=ClaudeCodeOptions(),
+                cli_path="/usr/bin/claude"
+            )
+            
+            mock_process = MagicMock()
+            mock_process.returncode = None
+            mock_process.wait = AsyncMock(return_value=None)
+            transport._process = mock_process
+            transport._stdout_stream = MockTextReceiveStream([buffered_line])
+            transport._stderr_stream = MockTextReceiveStream([])
+            
+            messages: list[Any] = []
+            async for msg in transport.receive_messages():
+                messages.append(msg)
+            
+            assert len(messages) == 2
+            assert messages[0]["content"] == "Line 1\nLine 2\nLine 3"
+            assert messages[1]["data"] == "Some\nMultiline\nContent"
+
+        anyio.run(_test)
+
+    def test_multiple_newlines_between_objects(self) -> None:
+        """Test parsing with multiple newlines between JSON objects."""
+        async def _test() -> None:
+            json_obj1 = {"type": "message", "id": "msg1"}
+            json_obj2 = {"type": "result", "id": "res1"}
+            
+            # Multiple newlines between objects
+            buffered_line = json.dumps(json_obj1) + '\n\n\n' + json.dumps(json_obj2)
+            
+            transport = SubprocessCLITransport(
+                prompt="test",
+                options=ClaudeCodeOptions(),
+                cli_path="/usr/bin/claude"
+            )
+            
+            mock_process = MagicMock()
+            mock_process.returncode = None
+            mock_process.wait = AsyncMock(return_value=None)
+            transport._process = mock_process
+            transport._stdout_stream = MockTextReceiveStream([buffered_line])
+            transport._stderr_stream = MockTextReceiveStream([])
+            
+            messages: list[Any] = []
+            async for msg in transport.receive_messages():
+                messages.append(msg)
+            
+            assert len(messages) == 2
+            assert messages[0]["id"] == "msg1"
+            assert messages[1]["id"] == "res1"
+
+        anyio.run(_test)