lucene/analysis/common/src/test/org/apache/lucene/analysis/snowball/TestSnowballPorterFilterFactory.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.snowball;

import java.io.Reader;
import java.io.StringReader;
import org.apache.lucene.analysis.BaseTokenStreamFactoryTestCase;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.util.StringMockResourceLoader;
import org.apache.lucene.util.Version;
import org.tartarus.snowball.ext.EnglishStemmer;

public class TestSnowballPorterFilterFactory extends BaseTokenStreamFactoryTestCase {

  public void test() throws Exception {
    String text = "The fledgling banks were counting on a big boom in banking";
    EnglishStemmer stemmer = new EnglishStemmer();
    String[] test = text.split("\\s");
    String[] gold = new String[test.length];
    for (int i = 0; i < test.length; i++) {
      stemmer.setCurrent(test[i]);
      stemmer.stem();
      gold[i] = stemmer.getCurrent();
    }

    Reader reader = new StringReader(text);
    TokenStream stream = whitespaceMockTokenizer(reader);
    stream = tokenFilterFactory("SnowballPorter", "language", "English").create(stream);
    assertTokenStreamContents(stream, gold);
  }

  /** Test the protected words mechanism of SnowballPorterFilterFactory */
  public void testProtected() throws Exception {
    Reader reader = new StringReader("ridding of some stemming");
    TokenStream stream = whitespaceMockTokenizer(reader);
    stream =
        tokenFilterFactory(
                "SnowballPorter",
                Version.LATEST,
                new StringMockResourceLoader("ridding"),
                "protected",
                "protwords.txt",
                "language",
                "English")
            .create(stream);

    assertTokenStreamContents(stream, new String[] {"ridding", "of", "some", "stem"});
  }

  /** Test that bogus arguments result in exception */
  public void testBogusArguments() throws Exception {
    IllegalArgumentException expected =
        expectThrows(
            IllegalArgumentException.class,
            () -> {
              tokenFilterFactory("SnowballPorter", "bogusArg", "bogusValue");
            });
    assertTrue(expected.getMessage().contains("Unknown parameters"));
  }
}