using System;

using System.Collections.Generic;

using System.Linq;

using Lucene.Net.Analysis;

using Lucene.Net.Analysis.En;

using Lucene.Net.Documents;

using Lucene.Net.Index;

using Lucene.Net.QueryParsers.Classic;

using Lucene.Net.Search;

using Lucene.Net.Store;

using Lucene.Net.Util;

​

using NUnit.Framework;

​

internal static class Program

{

    private static void Main()

    {

        var x = new NUnitLite.AutoRun().Execute(new string[]{"--test:TestAnalyzers", "--noc"});

        Console.WriteLine("");

        Console.WriteLine("----------------------------------------------");

        Console.WriteLine(x==0?"All Test Passed... :¬)": string.Format("{0} tests failed... :¬(", x));

        Console.WriteLine("----------------------------------------------");

    }

}

​

[TestFixture]

public class TestAnalyzers

{

    private const string FieldName = "CustomFieldName"; 

​

    public Directory CreateDirectory(IEnumerable<string> documents, Analyzer analyzer)

    {

        var directory = new RAMDirectory();

        var iwc = new IndexWriterConfig(LuceneVersion.LUCENE_48, analyzer)

        {

            OpenMode = OpenMode.CREATE_OR_APPEND,

        };

        var writer = new IndexWriter(directory, iwc);

        writer.Commit();

        foreach(var doc in documents) {

            var document = new Document();

            document.AddTextField(FieldName, doc, StoredField.Store.YES);

            writer.AddDocument(document);

        }

​

        writer.Flush(true, true);

        writer.Commit();

        return directory;

    }

​

    private QueryParser CreateQueryParser(Analyzer analyzer) 

        => new MultiFieldQueryParser(

        LuceneVersion.LUCENE_48,

        GetSearchFields(),

        analyzer);

​

    private string[] GetSearchFields() => new [] { FieldName };

​

​

​

    [TestCase("for", "for")]

    [TestCase("for", "forward")]

    [TestCase("forward", "for")]

    //[TestCase("retire", "retirement")]

    [TestCase("retirement", "retire")]

    [Test]

    public void TestPartialWordsStandard(string fieldValue, string query)

    {

        var analyzer = new EnglishAnalyzer(LuceneVersion.LUCENE_48);

        var directory = CreateDirectory(new [] { fieldValue }, analyzer);

​

        var indexReader = DirectoryReader.Open(directory);

        Assert.AreEqual(1, indexReader.NumDocs);

        var doc = indexReader.Document(0);

        Assert.NotNull(doc);

        Assert.AreEqual(fieldValue, doc.GetField(FieldName).GetStringValue());

​

​

        var searcher = new IndexSearcher(indexReader);

​

        var queryObj = CreateQueryParser(analyzer).Parse(query);

​

        var results = searcher.Search(queryObj, 2);

​

        Assert.AreEqual(1, results.TotalHits);

        doc = indexReader.Document(results.ScoreDocs.First().Doc);

        Assert.AreEqual(fieldValue, doc.GetField(FieldName).GetStringValue());

​

    }

}