package org.apidesign.delegatingwriter;

 import java.io.BufferedWriter;

 import java.io.IOException;

 import java.io.StringWriter;

 import org.junit.Before;

 import org.junit.Test;

 import static org.junit.Assert.*;

 /**

  *

  * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  */

 public class BufferedWriterThrowingExceptionTest {

     private StringWriter writer;

     public BufferedWriterThrowingExceptionTest() {

     }

     @Before

     public void setUp() {

         writer = new StringWriter();

     }

     @Test

     public void testBehaviourOfRealBufferInJDK() throws IOException {

         BufferedWriter bufferedWriter = new BufferedWriter(writer);

         doAppendHello(bufferedWriter, "Hello!");

         bufferedWriter.flush();

         assertEquals("Hello!", writer.toString());

     }

     @Test

     public void testBehaviourOfBufferThatThrowsExceptionWhenAppendIsCalled() throws IOException {

         BufferedWriter bufferedWriter = new AltBufferedWriter(writer, AltBufferedWriter.Behaviour.THROW_EXCEPTION);

         doAppendHello(bufferedWriter, "Hello!");

         bufferedWriter.flush();

         assertEquals("Hello!", writer.toString());

     }

     @Test

     public void testBehaviourWhenDelegatingConditionallyIsOK() throws IOException {

         BufferedWriter bufferedWriter = new AltBufferedWriter(writer, AltBufferedWriter.Behaviour.DELEGATE_CONDITIONALLY);

         doAppendHello(bufferedWriter, "Hello!");

         bufferedWriter.flush();

         assertEquals("Hello!", writer.toString());

     }

     private void doAppendHello(BufferedWriter bufferedWriter, CharSequence what) throws IOException {

         // BEGIN: writer.throw.client

         try {

             bufferedWriter.append(what);

         } catch (UnsupportedOperationException ex) {

             bufferedWriter.write(what.toString());

         }

         // END: writer.throw.client

     }

 }