/*

  * Copyright (c) 2011 David Saff

  * Copyright (c) 2011 Christian Gruber

  *

  * 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 org.truth0.subjects;

 import org.truth0.FailureStrategy;

 import org.truth0.util.ReflectionUtil;

 import com.google.common.annotations.GwtCompatible;

 import com.google.common.annotations.GwtIncompatible;

 @GwtCompatible

 public class ClassSubject extends Subject<ClassSubject, Class<?>> {

   public ClassSubject(FailureStrategy failureStrategy, Class<?> o) {

     super(failureStrategy, o);

   }

   // TODO(cgruber): Create an alternative implementation using JSNI.

   @GwtIncompatible("Reflection. ")

   public void declaresField(String fieldName) {

     if (getSubject() == null) {

       failureStrategy.fail("Cannot determine a field name from a null class.");

       return; // not all failures throw exceptions.

     }

     try {

       ReflectionUtil.getField(getSubject(), fieldName);

     } catch (NoSuchFieldException e) {

       StringBuilder message = new StringBuilder("Not true that ");

       message.append("<").append(getSubject().getSimpleName()).append(">");

       message.append(" has a field named <").append(fieldName).append(">");

       failureStrategy.fail(message.toString());

     }

   }

 }