src/Lucene.Net.Tests.Analysis.Phonetic/Language/NysiisTest.cs

using NUnit.Framework;
using System;
using Assert = Lucene.Net.TestFramework.Assert;

namespace Lucene.Net.Analysis.Phonetic.Language
{
    /*
     * 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.
     */

    public class NysiisTest : StringEncoderAbstractTest<Nysiis>
    {
        private readonly Nysiis fullNysiis = new Nysiis(false);

        /**
         * Takes an array of String pairs where each pair's first element is the input and the second element the expected
         * encoding.
         *
         * @param testValues
         *            an array of String pairs where each pair's first element is the input and the second element the
         *            expected encoding.
         * @throws EncoderException
         */
        private void AssertEncodings(params String[][] testValues)
        {
            foreach (String[]
                arr in testValues)
            {
                Assert.AreEqual(arr[1], this.fullNysiis.Encode(arr[0]), "Problem with " + arr[0]);
            }
        }

        protected override Nysiis CreateStringEncoder()
        {
            return new Nysiis();
        }

        private void EncodeAll(String[] strings, String expectedEncoding)
        {
            foreach (String str in strings)
            {
                Assert.AreEqual(expectedEncoding, StringEncoder.Encode(str), "Problem with " + str);
            }
        }

        [Test]
        public void TestBran()
        {
            EncodeAll(new String[] { "Brian", "Brown", "Brun" }, "BRAN");
        }

        [Test]
        public void TestCap()
        {
            this.EncodeAll(new String[] { "Capp", "Cope", "Copp", "Kipp" }, "CAP");
        }

        [Test]
        public void TestDad()
        {
            // Data Quality and Record Linkage Techniques P.121 claims this is DAN,
            // but it should be DAD, verified also with dropby.com
            this.EncodeAll(new String[] { "Dent" }, "DAD");
        }

        [Test]
        public void TestDan()
        {
            this.EncodeAll(new String[] { "Dane", "Dean", "Dionne" }, "DAN");
        }

        /**
         * Tests data gathered from around the internet.
         *
         * @see <a href="http://www.dropby.com/NYSIISTextStrings.html">http://www.dropby.com/NYSIISTextStrings.html</a>
         * @throws EncoderException
         */
        [Test]
        public void TestDropBy()
        {
            // Explanation of differences between this implementation and the one at dropby.com is
            // prepended to the test string. The referenced rules refer to the outlined steps the
            // class description for Nysiis.

            this.AssertEncodings(
                    // 1. Transcode first characters of name
                    new String[] { "MACINTOSH", "MCANT" },
                    // violates 4j: the second N should not be added, as the first
                    //              key char is already a N
                    new String[] { "KNUTH", "NAT" },           // Original: NNAT; modified: NATH
                                                               // O and E are transcoded to A because of rule 4a
                                                               // H also to A because of rule 4h
                                                               // the N gets mysteriously lost, maybe because of a wrongly implemented rule 4h
                                                               // that skips the next char in such a case?
                                                               // the remaining A is removed because of rule 7
                    new String[] { "KOEHN", "CAN" },           // Original: C
                                                               // violates 4j: see also KNUTH
                    new String[] { "PHILLIPSON", "FALAPSAN" }, // Original: FFALAP[SAN]
                                                               // violates 4j: see also KNUTH
                    new String[] { "PFEISTER", "FASTAR" },     // Original: FFASTA[R]
                                                               // violates 4j: see also KNUTH
                    new String[] { "SCHOENHOEFT", "SANAFT" },  // Original: SSANAF[T]
                                                               // 2. Transcode last characters of name:
                    new String[] { "MCKEE", "MCY" },
                    new String[] { "MACKIE", "MCY" },
                    new String[] { "HEITSCHMIDT", "HATSNAD" },
                    new String[] { "BART", "BAD" },
                    new String[] { "HURD", "HAD" },
                    new String[] { "HUNT", "HAD" },
                    new String[] { "WESTERLUND", "WASTARLAD" },
                    // 4. Transcode remaining characters by following these rules,
                    //    incrementing by one character each time:
                    new String[] { "CASSTEVENS", "CASTAFAN" },
                    new String[] { "VASQUEZ", "VASG" },
                    new String[] { "FRAZIER", "FRASAR" },
                    new String[] { "BOWMAN", "BANAN" },
                    new String[] { "MCKNIGHT", "MCNAGT" },
                    new String[] { "RICKERT", "RACAD" },
                    // violates 5: the last S is not removed
                    // when comparing to DEUTS, which is phonetically similar
                    // the result it also DAT, which is correct for DEUTSCH too imo
                    new String[] { "DEUTSCH", "DAT" },         // Original: DATS
                    new String[] { "WESTPHAL", "WASTFAL" },
                    // violates 4h: the H should be transcoded to S and thus ignored as
                    // the first key character is also S
                    new String[] { "SHRIVER", "SRAVAR" },      // Original: SHRAVA[R]
                                                               // same as KOEHN, the L gets mysteriously lost
                    new String[] { "KUHL", "CAL" },            // Original: C
                    new String[] { "RAWSON", "RASAN" },
                    // If last character is S, remove it
                    new String[] { "JILES", "JAL" },
                    // violates 6: if the last two characters are AY, remove A
                    new String[] { "CARRAWAY", "CARY" },       // Original: CARAY
                    new String[] { "YAMADA", "YANAD" });
        }

        [Test]
        public void TestFal()
        {
            this.EncodeAll(new String[] { "Phil" }, "FAL");
        }

        /**
         * Tests data gathered from around the internets.
         *
         * @throws EncoderException
         */
        [Test]
        public void TestOthers()
        {
            this.AssertEncodings(
                    new String[] { "O'Daniel", "ODANAL" },
                    new String[] { "O'Donnel", "ODANAL" },
                    new String[] { "Cory", "CARY" },
                    new String[] { "Corey", "CARY" },
                    new String[] { "Kory", "CARY" },
                    //
                    new String[] { "FUZZY", "FASY" });
        }

        /**
         * Tests rule 1: Translate first characters of name: MAC → MCC, KN → N, K → C, PH, PF → FF, SCH → SSS
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule1()
        {
            this.AssertEncodings(
                    new String[] { "MACX", "MCX" },
                    new String[] { "KNX", "NX" },
                    new String[] { "KX", "CX" },
                    new String[] { "PHX", "FX" },
                    new String[] { "PFX", "FX" },
                    new String[] { "SCHX", "SX" });
        }

        /**
         * Tests rule 2: Translate last characters of name: EE → Y, IE → Y, DT, RT, RD, NT, ND → D
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule2()
        {
            this.AssertEncodings(
                    new String[] { "XEE", "XY" },
                    new String[] { "XIE", "XY" },
                    new String[] { "XDT", "XD" },
                    new String[] { "XRT", "XD" },
                    new String[] { "XRD", "XD" },
                    new String[] { "XNT", "XD" },
                    new String[] { "XND", "XD" });
        }

        /**
         * Tests rule 4.1: EV → AF else A, E, I, O, U → A
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule4Dot1()
        {
            this.AssertEncodings(
                    new String[] { "XEV", "XAF" },
                    new String[] { "XAX", "XAX" },
                    new String[] { "XEX", "XAX" },
                    new String[] { "XIX", "XAX" },
                    new String[] { "XOX", "XAX" },
                    new String[] { "XUX", "XAX" });
        }

        /**
         * Tests rule 4.2: Q → G, Z → S, M → N
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule4Dot2()
        {
            this.AssertEncodings(
                    new String[] { "XQ", "XG" },
                    new String[] { "XZ", "X" },
                    new String[] { "XM", "XN" });
        }

        /**
         * Tests rule 5: If last character is S, remove it.
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule5()
        {
            this.AssertEncodings(
                    new String[] { "XS", "X" },
                    new String[] { "XSS", "X" });
        }

        /**
         * Tests rule 6: If last characters are AY, replace with Y.
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule6()
        {
            this.AssertEncodings(
                    new String[] { "XAY", "XY" },
                    new String[] { "XAYS", "XY" }); // Rules 5, 6
        }

        /**
         * Tests rule 7: If last character is A, remove it.
         *
         * @throws EncoderException
         */
        [Test]
        public void TestRule7()
        {
            this.AssertEncodings(
                    new String[] { "XA", "X" },
                    new String[] { "XAS", "X" }); // Rules 5, 7
        }
        [Test]
        public void TestSnad()
        {
            // Data Quality and Record Linkage Techniques P.121 claims this is SNAT,
            // but it should be SNAD
            this.EncodeAll(new String[] { "Schmidt" }, "SNAD");
        }

        [Test]
        public void TestSnat()
        {
            this.EncodeAll(new String[] { "Smith", "Schmit" }, "SNAT");
        }

        [Test]
        public void TestSpecialBranches()
        {
            this.EncodeAll(new String[] { "Kobwick" }, "CABWAC");
            this.EncodeAll(new String[] { "Kocher" }, "CACAR");
            this.EncodeAll(new String[] { "Fesca" }, "FASC");
            this.EncodeAll(new String[] { "Shom" }, "SAN");
            this.EncodeAll(new String[] { "Ohlo" }, "OL");
            this.EncodeAll(new String[] { "Uhu" }, "UH");
            this.EncodeAll(new String[] { "Um" }, "UN");
        }

        [Test]
        public void TestTranan()
        {
            this.EncodeAll(new String[] { "Trueman", "Truman" }, "TRANAN");
        }

        [Test]
        public void TestTrueVariant()
        {
            Nysiis encoder = new Nysiis(true);

            String encoded = encoder.Encode("WESTERLUND");
            Assert.True(encoded.Length <= 6);
            Assert.AreEqual("WASTAR", encoded);
        }
    }
}