NukkitExtension.java

/*
    This file is part of "nukkit xWorlds test tools".

    "nukkit xWorlds test tools" is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    "nukkit xWorlds test tools" is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with "nukkit xWorlds test tools". If not, see <http://www.gnu.org/licenses/>.

 */
package eu.xworlds.nukkit.test;

import java.lang.annotation.Annotation;
import java.lang.reflect.Parameter;

import org.junit.gen5.api.extension.AfterEachExtensionPoint;
import org.junit.gen5.api.extension.BeforeEachExtensionPoint;
import org.junit.gen5.api.extension.ExtensionContext;
import org.junit.gen5.api.extension.ExtensionContext.Namespace;
import org.junit.gen5.api.extension.ExtensionContext.Store;
import org.junit.gen5.api.extension.InstancePostProcessor;
import org.junit.gen5.api.extension.MethodInvocationContext;
import org.junit.gen5.api.extension.MethodParameterResolver;
import org.junit.gen5.api.extension.ParameterResolutionException;
import org.junit.gen5.api.extension.TestExtensionContext;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;

import cn.nukkit.Server;
import cn.nukkit.command.CommandReader;
import cn.nukkit.scheduler.ServerScheduler;
import eu.xworlds.nukkit.test.api.NukkitInject;
import eu.xworlds.nukkit.test.sample.PowermockExtension;
import eu.xworlds.nukkit.test.sample.PowermockState;
import jline.console.ConsoleReader;

/**
 * JUnit5 Extension for nukkit
 * 
 * @author mepeisen
 */
public class NukkitExtension implements InstancePostProcessor, MethodParameterResolver, AfterEachExtensionPoint, BeforeEachExtensionPoint
{
    
    /** the extension namespace */
    private static final Namespace NS = Namespace.of(NukkitExtension.class);
    
    @Override
    public void postProcessTestInstance(TestExtensionContext context) throws Exception
    {
        final PowermockState powermock = PowermockExtension.getState(context);
        powermock.getClassesToPrepare().add(Server.class);
        powermock.getClassesToPrepare().add(ConsoleReader.class);
        powermock.getClassesToPrepare().add(CommandReader.class);
        powermock.getClassesToPrepare().add(ServerScheduler.class);
        powermock.getPackagesToIgnore().add("org.mockito.*");
    }
    
    /**
     * @see org.junit.gen5.api.extension.AfterEachExtensionPoint#afterEach(org.junit.gen5.api.extension.TestExtensionContext)
     */
    @Override
    public void afterEach(TestExtensionContext context) throws Exception
    {
        // currently empty
    }
    
    /**
     * @see org.junit.gen5.api.extension.BeforeEachExtensionPoint#beforeEach(org.junit.gen5.api.extension.TestExtensionContext)
     */
    @Override
    public void beforeEach(TestExtensionContext context) throws Exception
    {
        // mokito support
        // final Class<?> mockitoClazz = context.getTestInstance().getClass().getClassLoader().loadClass(MockitoAnnotations.class.getName());
        // final Method initMocksMethod = mockitoClazz.getDeclaredMethod("initMocks", Object.class);
        // initMocksMethod.invoke(null, context.getTestInstance());
        MockitoAnnotations.initMocks(context.getTestInstance());
    }
    
    @Override
    public Object resolve(Parameter param, MethodInvocationContext methodInvocationContext, ExtensionContext extensionContext) throws ParameterResolutionException
    {
        final Store mocks = extensionContext.getStore(NS);
        return getMockWithoutCast(extensionContext, param.getType(), mocks, methodInvocationContext.getInstance().getClass().getClassLoader());
    }
    
    @Override
    public boolean supports(Parameter param, MethodInvocationContext methodInvocationContext, ExtensionContext extensionContext) throws ParameterResolutionException
    {
        for (final Annotation annot : param.getAnnotations())
        {
            if (annot.annotationType().getName().equals(NukkitInject.class.getName()))
                return true;
        }
        return false;
    }
    
    /**
     * Calculates the mocking class
     * 
     * @param extensionContext
     * @param mockType
     * @param mocks
     * @param loader
     * @return mocking class
     */
    private Object getMockWithoutCast(ExtensionContext extensionContext, Class<?> mockType, Store mocks, ClassLoader loader)
    {
        return mocks.getOrComputeIfAbsent(mockType, type -> mock(extensionContext, mockType, mocks, loader));
    }
    
    /**
     * Creates a mock
     * 
     * @param extensionContext
     * @param mockType
     * @param mocks
     * @param loader
     * @return mocking class
     */
    private Object mock(ExtensionContext extensionContext, Class<?> mockType, Store mocks, ClassLoader loader)
    {
        try
        {
            if (mockType.getName().equals(NukkitTestSession.class.getName()))
            {
                return loader.loadClass(NukkitTestSession.class.getName()).newInstance();
            }
            // TODO support additional nukkit classes
            
            // fall back to mockito
            // final Class<?> mockitoClazz = loader.loadClass(Mockito.class.getName());
            // final Method mockMethod = mockitoClazz.getDeclaredMethod("mock", Class.class);
            // return mockMethod.invoke(null, mockType);
            return Mockito.mock(mockType);
        }
        catch (Exception e)
        {
            throw new IllegalStateException(e);
        }
    }
    
}