TestReverseStringFilter.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.lucene.analysis.reverse;

import java.io.StringReader;

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.WhitespaceTokenizer;
import org.apache.lucene.analysis.tokenattributes.TermAttribute;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;

public class TestReverseStringFilter extends BaseTokenStreamTestCase {
  public void testFilter() throws Exception {
    TokenStream stream = new WhitespaceTokenizer(
        new StringReader("Do have a nice day"));     // 1-4 length string
    ReverseStringFilter filter = new ReverseStringFilter(stream);
    TermAttribute text = filter.getAttribute(TermAttribute.class);
    assertTrue(filter.incrementToken());
    assertEquals("oD", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("evah", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("a", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("ecin", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("yad", text.term());
    assertFalse(filter.incrementToken());
  }
  
  public void testFilterWithMark() throws Exception {
    TokenStream stream = new WhitespaceTokenizer(new StringReader(
        "Do have a nice day")); // 1-4 length string
    ReverseStringFilter filter = new ReverseStringFilter(stream, '\u0001');
    TermAttribute text = filter
        .getAttribute(TermAttribute.class);
    assertTrue(filter.incrementToken());
    assertEquals("\u0001oD", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("\u0001evah", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("\u0001a", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("\u0001ecin", text.term());
    assertTrue(filter.incrementToken());
    assertEquals("\u0001yad", text.term());
    assertFalse(filter.incrementToken());
  }

  public void testReverseString() throws Exception {
    assertEquals( "A", ReverseStringFilter.reverse( "A" ) );
    assertEquals( "BA", ReverseStringFilter.reverse( "AB" ) );
    assertEquals( "CBA", ReverseStringFilter.reverse( "ABC" ) );
  }
  
  public void testReverseChar() throws Exception {
    char[] buffer = { 'A', 'B', 'C', 'D', 'E', 'F' };
    ReverseStringFilter.reverse( buffer, 2, 3 );
    assertEquals( "ABEDCF", new String( buffer ) );
  }
}