"""Shared pytest fixtures for mcp_json_yaml_toml testing.
This module provides reusable test infrastructure following modern pytest patterns
with comprehensive type hints, proper fixture scoping, and external fixture files
for better maintainability.
"""
from __future__ import annotations
import json
from pathlib import Path
from typing import TYPE_CHECKING, Any
import pytest
from mcp_json_yaml_toml.tests.mcp_protocol_client import MCPClient
if TYPE_CHECKING:
from collections.abc import Generator
from pytest_mock import MockerFixture
# ==============================================================================
# Test Configuration
# ==============================================================================
FIXTURES_DIR = Path(__file__).parent / "fixtures"
# ==============================================================================
# Sample Config Fixtures
# ==============================================================================
@pytest.fixture
def sample_json_config(tmp_path: Path) -> Path:
"""Create sample JSON file for testing.
Tests: JSON format handling
How: Write sample JSON config to temp file
Why: Enable testing without hardcoded paths
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created JSON file
"""
config_data = {
"name": "test-app",
"version": "1.0.0",
"database": {
"host": "localhost",
"port": 5432,
"credentials": {"username": "admin", "password": "secret"},
},
"features": {"enabled": True, "beta": False},
"servers": ["server1.example.com", "server2.example.com"],
}
file_path = tmp_path / "config.json"
file_path.write_text(json.dumps(config_data, indent=2), encoding="utf-8")
return file_path
@pytest.fixture
def sample_yaml_config(tmp_path: Path) -> Path:
"""Create sample YAML file for testing.
Tests: YAML format handling
How: Write sample YAML config to temp file
Why: Enable testing YAML-specific features
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created YAML file
"""
yaml_content = """name: test-app
version: 1.0.0
database:
host: localhost
port: 5432
credentials:
username: admin
password: secret
features:
enabled: true
beta: false
servers:
- server1.example.com
- server2.example.com
"""
file_path = tmp_path / "config.yaml"
file_path.write_text(yaml_content, encoding="utf-8")
return file_path
@pytest.fixture
def sample_toml_config(tmp_path: Path) -> Path:
"""Create sample TOML file for testing.
Tests: TOML format handling
How: Write sample TOML config to temp file
Why: Enable testing TOML-specific features
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created TOML file
"""
toml_content = """name = "test-app"
version = "1.0.0"
[database]
host = "localhost"
port = 5432
[database.credentials]
username = "admin"
password = "secret"
[features]
enabled = true
beta = false
servers = ["server1.example.com", "server2.example.com"]
"""
file_path = tmp_path / "config.toml"
file_path.write_text(toml_content, encoding="utf-8")
return file_path
@pytest.fixture
def sample_xml_config(tmp_path: Path) -> Path:
"""Create sample XML file for testing.
Tests: XML format handling
How: Write sample XML config to temp file
Why: Enable testing XML-specific features
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created XML file
"""
xml_content = """<?xml version="1.0" encoding="UTF-8"?>
<config>
<name>test-app</name>
<version>1.0.0</version>
<database>
<host>localhost</host>
<port>5432</port>
<credentials>
<username>admin</username>
<password>secret</password>
</credentials>
</database>
<features>
<enabled>true</enabled>
<beta>false</beta>
</features>
<servers>
<server>server1.example.com</server>
<server>server2.example.com</server>
</servers>
</config>
"""
file_path = tmp_path / "config.xml"
file_path.write_text(xml_content, encoding="utf-8")
return file_path
# ==============================================================================
# Schema Fixtures
# ==============================================================================
@pytest.fixture
def sample_json_schema(tmp_path: Path) -> Path:
"""Create sample JSON schema file for validation testing.
Tests: Schema validation functionality
How: Write JSON schema to temp file
Why: Enable testing schema validation
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created JSON schema file
"""
schema_data = {
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"name": {"type": "string"},
"version": {"type": "string"},
"database": {
"type": "object",
"properties": {"host": {"type": "string"}, "port": {"type": "number"}},
"required": ["host", "port"],
},
},
"required": ["name", "version"],
}
schema_path = tmp_path / "config.schema.json"
schema_path.write_text(json.dumps(schema_data, indent=2), encoding="utf-8")
return schema_path
# ==============================================================================
# Invalid Config Fixtures
# ==============================================================================
@pytest.fixture
def invalid_json_config(tmp_path: Path) -> Path:
"""Create invalid JSON file for error testing.
Tests: JSON syntax error handling
How: Write malformed JSON to temp file
Why: Verify error handling for invalid syntax
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created invalid JSON file
"""
file_path = tmp_path / "invalid.json"
file_path.write_text('{"name": "test", "unclosed": ', encoding="utf-8")
return file_path
@pytest.fixture
def invalid_yaml_config(tmp_path: Path) -> Path:
"""Create invalid YAML file for error testing.
Tests: YAML syntax error handling
How: Write malformed YAML to temp file
Why: Verify error handling for invalid syntax
Args:
tmp_path: Pytest temporary directory
Returns:
Path to created invalid YAML file
"""
file_path = tmp_path / "invalid.yaml"
file_path.write_text(
"name: test\n bad_indent: value\nmore: [unclosed", encoding="utf-8"
)
return file_path
# ==============================================================================
# Mock Subprocess Fixtures
# ==============================================================================
@pytest.fixture
def mock_yq_success(mocker: MockerFixture) -> Any:
"""Mock successful yq subprocess execution.
Tests: Successful yq execution path
How: Mock subprocess.run to return successful result
Why: Enable unit testing without real yq binary
Args:
mocker: pytest-mock fixture
Returns:
Mocked subprocess.run function
"""
mock_result = mocker.Mock()
mock_result.returncode = 0
mock_result.stdout = b'{"result": "success"}'
mock_result.stderr = b""
return mocker.patch("subprocess.run", return_value=mock_result)
@pytest.fixture
def mock_yq_failure(mocker: MockerFixture) -> Any:
"""Mock failed yq subprocess execution.
Tests: Failed yq execution path
How: Mock subprocess.run to return error result
Why: Enable testing error handling without triggering real errors
Args:
mocker: pytest-mock fixture
Returns:
Mocked subprocess.run function
"""
mock_result = mocker.Mock()
mock_result.returncode = 1
mock_result.stdout = b""
mock_result.stderr = b"Error: invalid expression"
return mocker.patch("subprocess.run", return_value=mock_result)
# ==============================================================================
# Environment Variable Fixtures
# ==============================================================================
@pytest.fixture
def clean_environment(monkeypatch: pytest.MonkeyPatch) -> None:
"""Clean environment variables for isolated testing.
Tests: Environment variable isolation
How: Remove MCP_CONFIG_FORMATS env var
Why: Ensure tests don't interfere with each other
Args:
monkeypatch: Pytest monkeypatch fixture
"""
monkeypatch.delenv("MCP_CONFIG_FORMATS", raising=False)
@pytest.fixture
def json_only_environment(monkeypatch: pytest.MonkeyPatch) -> None:
"""Set environment to enable only JSON format.
Tests: Format filtering via environment
How: Set MCP_CONFIG_FORMATS to "json"
Why: Test format-specific behavior
Args:
monkeypatch: Pytest monkeypatch fixture
"""
monkeypatch.setenv("MCP_CONFIG_FORMATS", "json")
@pytest.fixture
def multi_format_environment(monkeypatch: pytest.MonkeyPatch) -> None:
"""Set environment to enable multiple formats.
Tests: Multiple format configuration
How: Set MCP_CONFIG_FORMATS to "json,yaml,toml"
Why: Test multi-format scenarios
Args:
monkeypatch: Pytest monkeypatch fixture
"""
monkeypatch.setenv("MCP_CONFIG_FORMATS", "json,yaml,toml")
# ==============================================================================
# Pytest Configuration
# ==============================================================================
def pytest_configure(config: Any) -> None:
"""Configure pytest with custom markers.
Args:
config: Pytest config object
"""
config.addinivalue_line(
"markers", "unit: marks unit tests with mocked dependencies"
)
config.addinivalue_line(
"markers", "integration: marks integration tests with real yq binary"
)
config.addinivalue_line(
"markers", "slow: marks tests as slow (deselect with '-m \"not slow\"')"
)
config.addinivalue_line(
"markers", "protocol: marks tests that use actual MCP JSON-RPC protocol"
)
# ==============================================================================
# MCP Protocol Client Fixtures
# ==============================================================================
@pytest.fixture
def mcp_client() -> Generator[MCPClient, None, None]:
"""Provide an MCP client connected via JSON-RPC protocol.
Tests: MCP protocol communication
How: Spawn MCP server subprocess, yield initialized client, cleanup on exit
Why: Enable tests to verify actual protocol behavior including serialization
This fixture spawns a new MCP server process for each test function,
ensuring complete isolation. The server communicates via stdin/stdout
using JSON-RPC 2.0 protocol.
Yields:
MCPClient: Initialized client ready for tool calls
"""
client = MCPClient()
client.start()
yield client
client.stop()
@pytest.fixture(scope="module")
def mcp_client_module() -> Generator[MCPClient, None, None]:
"""Provide an MCP client shared across a test module.
Tests: MCP protocol communication (shared instance)
How: Spawn MCP server subprocess once per module
Why: Improve test performance when isolation per-test is not needed
Use this fixture when tests within a module don't modify shared state
and can safely reuse the same MCP server process.
Yields:
MCPClient: Initialized client ready for tool calls
"""
client = MCPClient()
client.start()
yield client
client.stop()
