OpenAPI to Model Context Protocol (MCP)

# SPDX-License-Identifier: MIT # Copyright (c) 2025 Roger Gujord # https://github.com/gujord/OpenAPI-MCP """Tests for retry logic in fastmcp_server module.""" import pytest import asyncio import httpx from unittest.mock import Mock, AsyncMock, patch from openapi_mcp.fastmcp_server import ( retry_with_backoff, DEFAULT_MAX_RETRIES, DEFAULT_RETRY_BASE_DELAY, DEFAULT_RETRY_MAX_DELAY, RETRYABLE_STATUS_CODES, ) class TestRetryWithBackoff: """Tests for retry_with_backoff function.""" @pytest.mark.asyncio async def test_successful_first_attempt(self): """Test successful execution on first attempt.""" call_count = 0 async def success_func(): nonlocal call_count call_count += 1 return "success" result = await retry_with_backoff(success_func, max_retries=3) assert result == "success" assert call_count == 1 @pytest.mark.asyncio async def test_retry_on_connect_error(self): """Test retry on ConnectError.""" call_count = 0 async def failing_then_success(): nonlocal call_count call_count += 1 if call_count < 3: raise httpx.ConnectError("Connection failed") return "success" with patch("asyncio.sleep", new_callable=AsyncMock): result = await retry_with_backoff(failing_then_success, max_retries=3, base_delay=0.01) assert result == "success" assert call_count == 3 @pytest.mark.asyncio async def test_retry_on_timeout(self): """Test retry on TimeoutException.""" call_count = 0 async def timeout_then_success(): nonlocal call_count call_count += 1 if call_count < 2: raise httpx.TimeoutException("Request timed out") return "success" with patch("asyncio.sleep", new_callable=AsyncMock): result = await retry_with_backoff(timeout_then_success, max_retries=3, base_delay=0.01) assert result == "success" assert call_count == 2 @pytest.mark.asyncio async def test_max_retries_exhausted(self): """Test exception raised when max retries exhausted.""" async def always_failing(): raise httpx.ConnectError("Connection failed") with patch("asyncio.sleep", new_callable=AsyncMock): with pytest.raises(httpx.ConnectError): await retry_with_backoff(always_failing, max_retries=2, base_delay=0.01) @pytest.mark.asyncio async def test_no_retry_on_non_retryable_exception(self): """Test no retry on non-retryable exception.""" call_count = 0 async def value_error_func(): nonlocal call_count call_count += 1 raise ValueError("Not retryable") with pytest.raises(ValueError): await retry_with_backoff(value_error_func, max_retries=3) assert call_count == 1 # Only called once, no retries @pytest.mark.asyncio async def test_retry_on_retryable_status_codes(self): """Test retry on retryable HTTP status codes.""" call_count = 0 # Test each retryable status code for status_code in [429, 500, 502, 503, 504]: call_count = 0 async def retryable_status(): nonlocal call_count call_count += 1 if call_count < 2: response = Mock() response.status_code = status_code response.headers = {} raise httpx.HTTPStatusError( f"HTTP {status_code}", request=Mock(), response=response ) return "success" with patch("asyncio.sleep", new_callable=AsyncMock): result = await retry_with_backoff(retryable_status, max_retries=3, base_delay=0.01) assert result == "success" assert call_count == 2 @pytest.mark.asyncio async def test_no_retry_on_non_retryable_status_code(self): """Test no retry on non-retryable status codes like 400, 401, 404.""" for status_code in [400, 401, 403, 404, 405]: call_count = 0 async def non_retryable_status(): nonlocal call_count call_count += 1 response = Mock() response.status_code = status_code response.headers = {} raise httpx.HTTPStatusError( f"HTTP {status_code}", request=Mock(), response=response ) with pytest.raises(httpx.HTTPStatusError): await retry_with_backoff(non_retryable_status, max_retries=3, base_delay=0.01) assert call_count == 1 # Only one attempt, no retries @pytest.mark.asyncio async def test_retry_after_header_respected(self): """Test that Retry-After header is respected.""" call_count = 0 sleep_durations = [] async def mock_sleep(duration): sleep_durations.append(duration) async def rate_limited_then_success(): nonlocal call_count call_count += 1 if call_count < 2: response = Mock() response.status_code = 429 response.headers = {"Retry-After": "5"} raise httpx.HTTPStatusError( "HTTP 429", request=Mock(), response=response ) return "success" with patch("asyncio.sleep", side_effect=mock_sleep): result = await retry_with_backoff(rate_limited_then_success, max_retries=3, base_delay=0.01) assert result == "success" assert len(sleep_durations) == 1 assert sleep_durations[0] == 5.0 # Respects Retry-After header @pytest.mark.asyncio async def test_logging_on_retry(self): """Test that retries are logged when logger provided.""" logger = Mock() call_count = 0 async def failing_then_success(): nonlocal call_count call_count += 1 if call_count < 2: raise httpx.ConnectError("Connection failed") return "success" with patch("asyncio.sleep", new_callable=AsyncMock): result = await retry_with_backoff( failing_then_success, max_retries=3, base_delay=0.01, logger=logger ) assert result == "success" assert logger.warning.called @pytest.mark.asyncio async def test_logging_on_exhaustion(self): """Test that exhaustion is logged when logger provided.""" logger = Mock() async def always_failing(): raise httpx.ConnectError("Connection failed") with patch("asyncio.sleep", new_callable=AsyncMock): with pytest.raises(httpx.ConnectError): await retry_with_backoff(always_failing, max_retries=1, base_delay=0.01, logger=logger) assert logger.error.called class TestRetryConstants: """Tests for retry constants.""" def test_default_max_retries(self): """Test default max retries value.""" assert DEFAULT_MAX_RETRIES == 3 def test_default_base_delay(self): """Test default base delay value.""" assert DEFAULT_RETRY_BASE_DELAY == 1.0 def test_default_max_delay(self): """Test default max delay value.""" assert DEFAULT_RETRY_MAX_DELAY == 30.0 def test_retryable_status_codes(self): """Test retryable status codes set.""" assert 408 in RETRYABLE_STATUS_CODES # Request Timeout assert 429 in RETRYABLE_STATUS_CODES # Too Many Requests assert 500 in RETRYABLE_STATUS_CODES # Internal Server Error assert 502 in RETRYABLE_STATUS_CODES # Bad Gateway assert 503 in RETRYABLE_STATUS_CODES # Service Unavailable assert 504 in RETRYABLE_STATUS_CODES # Gateway Timeout # Non-retryable codes should not be in the set assert 400 not in RETRYABLE_STATUS_CODES assert 401 not in RETRYABLE_STATUS_CODES assert 404 not in RETRYABLE_STATUS_CODES