GuiceBerryRule.java

/*
 * Copyright (C) 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.guiceberry.junit4;

import com.google.guiceberry.DefaultEnvSelector;
import com.google.guiceberry.GuiceBerry;
import com.google.guiceberry.GuiceBerry.GuiceBerryWrapper;
import com.google.guiceberry.GuiceBerryEnvSelector;
import com.google.guiceberry.TestDescription;
import com.google.inject.Module;
import org.junit.rules.MethodRule;
import org.junit.rules.TestRule;
import org.junit.runners.model.FrameworkMethod;
import org.junit.runners.model.Statement;

/**
 * {@link GuiceBerry} adapter for JUnit4 tests.
 *
 * <p>If you are looking for a {@link TestRule}, see {@link GuiceBerryTestRule}. Note that the
 * {@link MethodRule} is the preferred implementation to use for being less error-prone.
 *
 * @author Luiz-Otavio "Z" Zorzella
 */
public class GuiceBerryRule implements MethodRule {

  private final GuiceBerryEnvSelector guiceBerryEnvSelector;

  public GuiceBerryRule(Class<? extends Module> envClass) {
    this(DefaultEnvSelector.of(envClass));
  }

  public GuiceBerryRule(GuiceBerryEnvSelector guiceBerryEnvSelector) {
    this.guiceBerryEnvSelector = guiceBerryEnvSelector;
  }

  public Statement apply(final Statement base, final FrameworkMethod method, final Object target) {
    return buildStatement(base, guiceBerryEnvSelector, target, method.getName());
  }

  static Statement buildStatement(
      final Statement base,
      final GuiceBerryEnvSelector guiceBerryEnvSelector,
      final Object target,
      final String suffix) {
    return new Statement() {
      @Override
      public void evaluate() throws Throwable {
        final GuiceBerryWrapper setupAndTearDown =
          GuiceBerry.INSTANCE.buildWrapper(
              new TestDescription(target, target.getClass().getName() + "." + suffix),
              guiceBerryEnvSelector);
        try {
          setupAndTearDown.runBeforeTest();
          base.evaluate();
        } finally {
          setupAndTearDown.runAfterTest();
        }
      }
    };
  }
}