Plugin System

class Plugin:
    """
    Base plugin interface for Poetry extensions.
    
    Abstract base class that all Poetry plugins must implement
    to integrate with Poetry's functionality.
    """
    
    def activate(self, poetry: Poetry, io) -> None:
        """
        Activate plugin with Poetry instance.
        
        Args:
            poetry: Poetry instance
            io: IO interface for output
            
        Raises:
            NotImplementedError: Must be implemented by plugins
        """

class ApplicationPlugin:
    """
    Plugin interface for CLI command extensions.
    
    Allows plugins to register custom commands with Poetry's
    command-line interface.
    """
    
    @property
    def commands(self) -> list:
        """
        List of command classes to register.
        
        Returns:
            List of command class instances
        """
    
    def activate(self, application) -> None:
        """
        Activate plugin with CLI application.
        
        Args:
            application: CLI application instance
        """

class PluginManager:
    """
    Plugin discovery and management system.
    
    Handles loading, activating, and managing Poetry plugins
    with support for entry point discovery and error handling.
    """
    
    def __init__(self, group: str = "poetry.plugin"):
        """
        Initialize plugin manager.
        
        Args:
            group: Entry point group for plugin discovery
        """
    
    def load_plugins(self, env: Env = None) -> None:
        """
        Load plugins from entry points.
        
        Args:
            env: Environment for plugin loading
        """
    
    def activate_plugins(self, poetry: Poetry, io = None) -> None:
        """
        Activate loaded plugins.
        
        Args:
            poetry: Poetry instance
            io: IO interface
        """
    
    def get_plugin(self, name: str):
        """
        Get plugin by name.
        
        Args:
            name: Plugin name
            
        Returns:
            Plugin instance or None
        """
    
    def has_plugins(self) -> bool:
        """
        Check if any plugins are loaded.
        
        Returns:
            True if plugins are available
        """

from poetry.plugins.plugin import Plugin

class MyPlugin(Plugin):
    """Example Poetry plugin."""
    
    def activate(self, poetry, io):
        """Activate plugin functionality."""
        io.write_line("My plugin activated!")
        
        # Access Poetry functionality
        project_name = poetry.package.name
        io.write_line(f"Working with project: {project_name}")
        
        # Plugin-specific initialization
        self.setup_custom_functionality(poetry)
    
    def setup_custom_functionality(self, poetry):
        """Setup plugin-specific functionality."""
        pass

from poetry.plugins.application_plugin import ApplicationPlugin
from poetry.console.commands.command import Command

class MyCommand(Command):
    """Custom Poetry command."""
    
    name = "my-command"
    description = "My custom command"
    
    def handle(self):
        """Handle command execution."""
        self.line("Executing my custom command!")
        
        # Access Poetry instance
        poetry = self.poetry
        self.line(f"Project: {poetry.package.name}")
        
        # Custom command logic
        return 0

class MyCommandPlugin(ApplicationPlugin):
    """Plugin that adds custom commands."""
    
    @property
    def commands(self):
        """Return list of commands to register."""
        return [MyCommand()]
    
    def activate(self, application):
        """Activate plugin with application."""
        pass  # Commands are automatically registered

[tool.poetry.plugins."poetry.plugin"]
my-plugin = "my_package.plugins:MyPlugin"

[tool.poetry.plugins."poetry.application.plugin"]
my-commands = "my_package.plugins:MyCommandPlugin"

from poetry.plugins.plugin import Plugin

class ConfigExtensionPlugin(Plugin):
    """Plugin that extends configuration options."""
    
    def activate(self, poetry, io):
        """Add custom configuration handling."""
        config = poetry.config
        
        # Add custom configuration defaults
        custom_config = {
            "my-plugin.enabled": True,
            "my-plugin.custom-setting": "value"
        }
        config.merge(custom_config)
        
        # Register configuration validators
        self.register_validators(config)
    
    def register_validators(self, config):
        """Register custom configuration validators."""
        pass

from poetry.plugins.plugin import Plugin
from poetry.repositories.repository import Repository

class CustomRepository(Repository):
    """Custom repository implementation."""
    
    def __init__(self, name, url, config):
        """Initialize custom repository."""
        super().__init__(name)
        self.url = url
        self.config = config
    
    def find_packages(self, dependency):
        """Find packages in custom repository."""
        # Custom package discovery logic
        return []

class RepositoryPlugin(Plugin):
    """Plugin that adds custom repository support."""
    
    def activate(self, poetry, io):
        """Register custom repository."""
        # Add custom repository to pool
        custom_repo = CustomRepository(
            name="custom",
            url="https://custom-repo.example.com",
            config=poetry.config
        )
        
        poetry.pool.add_repository(custom_repo, priority="supplemental")

from poetry.plugins.plugin import Plugin

class BuildIntegrationPlugin(Plugin):
    """Plugin that integrates with build systems."""
    
    def activate(self, poetry, io):
        """Setup build system integration."""
        # Hook into build process
        self.setup_build_hooks(poetry)
        
        # Add custom build steps
        self.register_build_steps(poetry)
    
    def setup_build_hooks(self, poetry):
        """Setup hooks for build process."""
        # Pre-build hooks
        # Post-build hooks
        pass
    
    def register_build_steps(self, poetry):
        """Register custom build steps."""
        pass

from poetry.plugins.plugin_manager import PluginManager
from poetry.factory import Factory

def test_plugin_activation():
    """Test plugin activation."""
    # Create Poetry instance
    poetry = Factory().create_poetry()
    
    # Create plugin manager
    plugin_manager = PluginManager()
    
    # Load and activate plugins
    plugin_manager.load_plugins()
    plugin_manager.activate_plugins(poetry)
    
    # Test plugin functionality
    assert plugin_manager.has_plugins()

import pytest
from poetry.console.application import Application

def test_command_plugin():
    """Test command plugin integration."""
    # Create application with plugins
    app = Application()
    
    # Test custom command availability
    assert app.has("my-command")
    
    # Test command execution
    tester = ApplicationTester(app)
    tester.execute("my-command")
    
    assert tester.status_code == 0

class PluginError(PoetryError):
    """Base plugin error."""

class PluginLoadError(PluginError):
    """Plugin loading failures."""

class PluginActivationError(PluginError):
    """Plugin activation errors."""

class InvalidPluginError(PluginError):
    """Invalid plugin configuration or implementation."""