Test Utilities

class CheckerTestCase:
    """
    Base class for checker unit tests.
    
    Provides utilities for testing individual checkers
    with AST nodes and message validation.
    """
    
    CHECKER_CLASS = None  # Set to checker class being tested
    
    def setup_method(self):
        """Setup test environment before each test method."""
    
    def walk(self, node):
        """
        Walk AST node with the checker.
        
        Args:
            node: AST node to walk
        """
    
    def assertNoMessages(self):
        """Assert that no messages were generated."""
    
    def assertAddsMessages(self, *messages):
        """
        Assert that specific messages were added.
        
        Args:
            *messages: Expected MessageTest instances
        """

class MessageTest:
    """
    Test representation of an expected message.
    
    Used to verify that checkers generate expected
    messages for specific code patterns.
    """
    
    def __init__(self, msg_id, node=None, line=None, args=None, 
                 confidence=None, col_offset=None, end_line=None, 
                 end_col_offset=None):
        """
        Initialize message test.
        
        Args:
            msg_id (str): Expected message ID
            node: Expected AST node (optional)
            line (int): Expected line number
            args (tuple): Expected message arguments
            confidence (str): Expected confidence level
            col_offset (int): Expected column offset
            end_line (int): Expected end line
            end_col_offset (int): Expected end column
        """

class FunctionalTestFile:
    """
    Functional test file representation.
    
    Represents a Python file used for functional testing
    with expected messages and configuration.
    """
    
    def __init__(self, directory, filename):
        """
        Initialize functional test file.
        
        Args:
            directory (str): Directory containing test file
            filename (str): Test file name
        """
    
    @property
    def expected_messages(self):
        """
        Get expected messages from test file.
        
        Returns:
            list: Expected message objects
        """
    
    @property 
    def pylintrc(self):
        """
        Get pylintrc path for test.
        
        Returns:
            str: Path to test-specific pylintrc
        """

class LintModuleTest:
    """
    Module linting test utilities.
    
    Provides utilities for testing pylint behavior
    on complete modules and packages.
    """
    
    def __init__(self, test_file):
        """
        Initialize module test.
        
        Args:
            test_file: FunctionalTestFile instance
        """
    
    def runTest(self):
        """Run the functional test."""
    
    def _check_result(self, got_messages, expected_messages):
        """
        Check test results against expectations.
        
        Args:
            got_messages (list): Actual messages from pylint
            expected_messages (list): Expected messages
        """

class UnittestLinter:
    """
    Test-specific linter implementation.
    
    Simplified linter for unit testing that provides
    controlled environment and message collection.
    """
    
    def __init__(self):
        """Initialize unittest linter."""
        self.config = None
        self.reporter = None
    
    def check(self, files_or_modules):
        """
        Check files for testing.
        
        Args:
            files_or_modules: Files or modules to check
        """
    
    def add_message(self, msg_id, line=None, node=None, args=None,
                   confidence=None, col_offset=None):
        """
        Add message during testing.
        
        Args:
            msg_id (str): Message identifier
            line (int): Line number
            node: AST node
            args (tuple): Message arguments  
            confidence (str): Confidence level
            col_offset (int): Column offset
        """

def set_config(**kwargs):
    """
    Set configuration for tests.
    
    Provides a convenient way to set pylint configuration
    options during test execution.
    
    Args:
        **kwargs: Configuration options to set
        
    Example:
        set_config(max_line_length=100, disable=['missing-docstring'])
    """

def tokenize_str(code):
    """
    Tokenize Python code string.
    
    Utility function for testing token-based checkers
    by converting code strings to token streams.
    
    Args:
        code (str): Python code to tokenize
        
    Returns:
        list: Token objects
    """

class GenericTestReporter:
    """
    Generic test reporter.
    
    Collects messages during testing for validation
    and provides access to test results.
    """
    
    def __init__(self):
        """Initialize generic test reporter."""
        self.messages = []
    
    def handle_message(self, msg):
        """
        Handle message during testing.
        
        Args:
            msg: Message to collect
        """
        self.messages.append(msg)
    
    def finalize(self):
        """
        Finalize testing and return results.
        
        Returns:
            list: Collected messages
        """
        return self.messages

class MinimalTestReporter:
    """
    Minimal test reporter.
    
    Provides minimal message collection for
    lightweight testing scenarios.
    """
    
    def __init__(self):
        """Initialize minimal reporter."""
        self.messages = []

class FunctionalTestReporter:
    """
    Functional test reporter.
    
    Specialized reporter for functional testing
    with enhanced message formatting and comparison.
    """
    
    def __init__(self):
        """Initialize functional test reporter."""
        self.messages = []
    
    def display_reports(self, layout):
        """Display functional test reports."""
        pass

import astroid
from pylint.testutils import CheckerTestCase, MessageTest
from my_checkers import FunctionNamingChecker

class TestFunctionNamingChecker(CheckerTestCase):
    """Test cases for function naming checker."""
    
    CHECKER_CLASS = FunctionNamingChecker
    
    def test_function_with_good_name(self):
        """Test that functions with good names pass."""
        node = astroid.extract_node('''
        def get_user_name(): #@
            return "test"
        ''')
        
        with self.assertNoMessages():
            self.walk(node)
    
    def test_function_with_bad_name(self):
        """Test that functions with bad names fail."""
        node = astroid.extract_node('''
        def userName(): #@
            return "test"
        ''')
        
        expected_message = MessageTest(
            msg_id='invalid-function-name',
            node=node,
            args=('userName',),
            line=2,
            col_offset=0
        )
        
        with self.assertAddsMessages(expected_message):
            self.walk(node)
    
    def test_function_with_config(self):
        """Test checker with custom configuration."""
        with self.assertNoMessages():
            # Set custom configuration
            self.checker.config.allowed_function_prefixes = ['create', 'build']
            
            node = astroid.extract_node('''
            def create_object(): #@
                pass
            ''')
            
            self.walk(node)

from pylint.testutils import FunctionalTestFile, LintModuleTest
import os

class TestMyCheckersFunctional:
    """Functional tests for custom checkers."""
    
    def test_complex_scenarios(self):
        """Test complex scenarios with functional tests."""
        test_dir = 'tests/functional'
        test_file = 'my_checker_test.py'
        
        functional_test = FunctionalTestFile(test_dir, test_file)
        test_case = LintModuleTest(functional_test)
        test_case.runTest()
    
    def create_functional_test_file(self):
        """Create a functional test file."""
        test_content = '''
"""Test module for custom checker."""

def bad_function_name():  # [invalid-function-name]
    """This should trigger a naming violation."""
    pass

def get_value():  # No violation expected
    """This should pass naming validation.""" 
    return 42

class BadClassName:  # [invalid-class-name]
    """This should trigger a class naming violation."""
    pass
'''
        
        with open('tests/functional/my_checker_test.py', 'w') as f:
            f.write(test_content)

from pylint.testutils import UnittestLinter, GenericTestReporter

class CustomTestFramework:
    """Custom testing framework for specific needs."""
    
    def __init__(self):
        self.linter = UnittestLinter()
        self.reporter = GenericTestReporter()
        self.linter.set_reporter(self.reporter)
    
    def test_code_snippet(self, code, expected_messages=None):
        """
        Test a code snippet and validate results.
        
        Args:
            code (str): Python code to test
            expected_messages (list): Expected message IDs
        """
        # Create temporary file
        import tempfile
        with tempfile.NamedTemporaryFile(mode='w', suffix='.py', 
                                       delete=False) as f:
            f.write(code)
            temp_file = f.name
        
        try:
            # Run pylint on the code
            self.linter.check([temp_file])
            messages = self.reporter.finalize()
            
            # Validate results
            if expected_messages:
                actual_msg_ids = [msg.msg_id for msg in messages]
                assert set(actual_msg_ids) == set(expected_messages), \
                    f"Expected {expected_messages}, got {actual_msg_ids}"
            
            return messages
        finally:
            # Clean up
            import os
            os.unlink(temp_file)
    
    def assert_no_violations(self, code):
        """Assert that code has no violations."""
        messages = self.test_code_snippet(code)
        assert len(messages) == 0, f"Unexpected violations: {messages}"
    
    def assert_violations(self, code, expected_msg_ids):
        """Assert that code has specific violations."""
        self.test_code_snippet(code, expected_msg_ids)

# Usage example
framework = CustomTestFramework()

# Test clean code
framework.assert_no_violations('''
def get_user_data():
    """Get user data from database."""
    return {"name": "test"}
''')

# Test code with violations
framework.assert_violations('''
def userData():  # Missing docstring, bad naming
    return {"name": "test"}
''', ['missing-docstring', 'invalid-name'])

from unittest.mock import patch, MagicMock
from pylint.testutils import CheckerTestCase

class TestCheckerWithMocks(CheckerTestCase):
    """Test checker using mocks for external dependencies."""
    
    CHECKER_CLASS = MyCustomChecker
    
    @patch('mypackage.external_service.check_api')
    def test_checker_with_external_service(self, mock_api):
        """Test checker that depends on external service."""
        # Setup mock
        mock_api.return_value = True
        
        node = astroid.extract_node('''
        def process_data(): #@
            # This would normally call external service
            pass
        ''')
        
        with self.assertNoMessages():
            self.walk(node)
        
        # Verify mock was called
        mock_api.assert_called_once()
    
    def test_checker_with_mock_config(self):
        """Test checker with mocked configuration."""
        # Mock configuration
        mock_config = MagicMock()
        mock_config.strict_mode = True
        mock_config.threshold = 10
        
        self.checker.config = mock_config
        
        node = astroid.extract_node('''
        def test_function(): #@
            pass
        ''')
        
        # Test behavior changes based on config
        with self.assertAddsMessages(
            MessageTest('strict-mode-violation', node=node)
        ):
            self.walk(node)

import time
from pylint.testutils import CheckerTestCase

class TestCheckerPerformance(CheckerTestCase):
    """Performance tests for checker efficiency."""
    
    CHECKER_CLASS = MyPerformanceChecker
    
    def test_checker_performance(self):
        """Test checker performance on large code."""
        # Generate large test case
        large_code = '''
def large_function():
    """Large function for performance testing."""
''' + '\n'.join([f'    var_{i} = {i}' for i in range(1000)])
        
        node = astroid.parse(large_code)
        
        # Measure execution time
        start_time = time.time()
        self.walk(node)
        end_time = time.time()
        
        execution_time = end_time - start_time
        
        # Assert reasonable performance
        assert execution_time < 1.0, \
            f"Checker too slow: {execution_time:.2f}s"
        
        # Verify functionality still works
        self.assertNoMessages()  # or expected messages
    
    def benchmark_checker(self, iterations=100):
        """Benchmark checker performance."""
        node = astroid.extract_node('''
        def benchmark_function(): #@
            return "test"
        ''')
        
        total_time = 0
        for _ in range(iterations):
            start = time.time()
            self.walk(node)
            total_time += time.time() - start
        
        avg_time = total_time / iterations
        print(f"Average execution time: {avg_time*1000:.2f}ms")
        
        return avg_time

# Configure test environment
from pylint.testutils import set_config

def setup_test_config():
    """Setup common test configuration."""
    set_config(
        disable=['missing-docstring'],  # Disable for test simplicity
        max_line_length=120,            # Longer lines in tests
        good_names=['i', 'j', 'k', 'x', 'y', 'z', 'test_var'],
        reports=False,                  # Disable reports in tests
        score=False                     # Disable scoring in tests
    )

# Test-specific pylintrc
TEST_PYLINTRC = '''
[MAIN]
load-plugins=my_test_plugin

[MESSAGES CONTROL]
disable=missing-docstring,invalid-name

[BASIC]
good-names=i,j,k,x,y,z,test_var,mock_obj

[FORMAT]
max-line-length=120

[REPORTS]
reports=no
score=no
'''

def run_test_suite():
    """Run complete test suite for CI/CD."""
    import unittest
    import sys
    
    # Discover and run all tests
    loader = unittest.TestLoader()
    suite = loader.discover('tests/', pattern='test_*.py')
    
    runner = unittest.TextTestRunner(verbosity=2)
    result = runner.run(suite)
    
    # Exit with error code if tests failed
    if not result.wasSuccessful():
        sys.exit(1)
    
    print(f"All tests passed: {result.testsRun} tests")

# GitHub Actions example
'''
name: Test Custom Checkers
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: [3.8, 3.9, '3.10', 3.11]
    steps:
    - uses: actions/checkout@v2
    - name: Set up Python
      uses: actions/setup-python@v2
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install dependencies
      run: |
        pip install pylint pytest
        pip install -e .
    - name: Run tests
      run: python -m pytest tests/
    - name: Run functional tests
      run: python run_test_suite.py
'''