Fix beidermorse phonetic token filter for unspecified languageset (#27112)

Currently, when we create a BeiderMorseFilter with an unspecified `languageset`,
the filter will not guess the language, which should be the default behaviour.
This change fixes this and adds a simple test for the cases with and without
provided `languageset` settings.

Closes #26771

Author: cbuescher

plugins/analysis-phonetic/src/main/java/org/elasticsearch/index/analysis/PhoneticTokenFilterFactory.java

@@ -19,9 +19,6 @@
 
 package org.elasticsearch.index.analysis;
 
-import java.util.HashSet;
-import java.util.List;
-
 import org.apache.commons.codec.Encoder;
 import org.apache.commons.codec.language.Caverphone1;
 import org.apache.commons.codec.language.Caverphone2;
@@ -45,6 +42,9 @@
 import org.elasticsearch.index.analysis.phonetic.KoelnerPhonetik;
 import org.elasticsearch.index.analysis.phonetic.Nysiis;
 
+import java.util.HashSet;
+import java.util.List;
+
 public class PhoneticTokenFilterFactory extends AbstractTokenFilterFactory {
 
     private final Encoder encoder;
@@ -116,11 +116,11 @@ public PhoneticTokenFilterFactory(IndexSettings indexSettings, Environment envir
     public TokenStream create(TokenStream tokenStream) {
         if (encoder == null) {
             if (ruletype != null && nametype != null) {
-                if (languageset != null) {
-                    final LanguageSet languages = LanguageSet.from(new HashSet<>(languageset));
-                    return new BeiderMorseFilter(tokenStream, new PhoneticEngine(nametype, ruletype, true), languages);
+                LanguageSet langset = null;
+                if (languageset != null && languageset.size() > 0) {
+                    langset = LanguageSet.from(new HashSet<>(languageset));
                 }
-                return new BeiderMorseFilter(tokenStream, new PhoneticEngine(nametype, ruletype, true));
+                return new BeiderMorseFilter(tokenStream, new PhoneticEngine(nametype, ruletype, true), langset);
             }
             if (maxcodelength > 0) {
                 return new DoubleMetaphoneFilter(tokenStream, maxcodelength, !replace);

plugins/analysis-phonetic/src/test/java/org/elasticsearch/index/analysis/SimplePhoneticAnalysisTests.java

@@ -19,26 +19,57 @@
 
 package org.elasticsearch.index.analysis;
 
+import org.apache.lucene.analysis.BaseTokenStreamTestCase;
+import org.apache.lucene.analysis.Tokenizer;
+import org.apache.lucene.analysis.core.WhitespaceTokenizer;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.plugin.analysis.AnalysisPhoneticPlugin;
 import org.elasticsearch.test.ESTestCase;
 import org.hamcrest.MatcherAssert;
+import org.junit.Before;
 
 import java.io.IOException;
+import java.io.StringReader;
 
 import static org.hamcrest.Matchers.instanceOf;
 
 public class SimplePhoneticAnalysisTests extends ESTestCase {
-    public void testPhoneticTokenFilterFactory() throws IOException {
+
+    private TestAnalysis analysis;
+
+    @Before
+    public void setup() throws IOException {
         String yaml = "/org/elasticsearch/index/analysis/phonetic-1.yml";
         Settings settings = Settings.builder().loadFromStream(yaml, getClass().getResourceAsStream(yaml), false)
                 .put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT)
                 .build();
-        TestAnalysis analysis = createTestAnalysis(new Index("test", "_na_"), settings, new AnalysisPhoneticPlugin());
+        this.analysis = createTestAnalysis(new Index("test", "_na_"), settings, new AnalysisPhoneticPlugin());
+    }
+
+    public void testPhoneticTokenFilterFactory() throws IOException {
         TokenFilterFactory filterFactory = analysis.tokenFilter.get("phonetic");
         MatcherAssert.assertThat(filterFactory, instanceOf(PhoneticTokenFilterFactory.class));
     }
+
+    public void testPhoneticTokenFilterBeiderMorseNoLanguage() throws IOException {
+        TokenFilterFactory filterFactory = analysis.tokenFilter.get("beidermorsefilter");
+        Tokenizer tokenizer = new WhitespaceTokenizer();
+        tokenizer.setReader(new StringReader("ABADIAS"));
+        String[] expected = new String[] { "abYdias", "abYdios", "abadia", "abadiaS", "abadias", "abadio", "abadioS", "abadios", "abodia",
+                "abodiaS", "abodias", "abodio", "abodioS", "abodios", "avadias", "avadios", "avodias", "avodios", "obadia", "obadiaS",
+                "obadias", "obadio", "obadioS", "obadios", "obodia", "obodiaS", "obodias", "obodioS" };
+        BaseTokenStreamTestCase.assertTokenStreamContents(filterFactory.create(tokenizer), expected);
+    }
+
+    public void testPhoneticTokenFilterBeiderMorseWithLanguage() throws IOException {
+        TokenFilterFactory filterFactory = analysis.tokenFilter.get("beidermorsefilterfrench");
+        Tokenizer tokenizer = new WhitespaceTokenizer();
+        tokenizer.setReader(new StringReader("Rimbault"));
+        String[] expected = new String[] { "rimbD", "rimbDlt", "rimba", "rimbalt", "rimbo", "rimbolt", "rimbu", "rimbult", "rmbD", "rmbDlt",
+                "rmba", "rmbalt", "rmbo", "rmbolt", "rmbu", "rmbult" };
+        BaseTokenStreamTestCase.assertTokenStreamContents(filterFactory.create(tokenizer), expected);
+    }
 }

plugins/analysis-phonetic/src/test/resources/org/elasticsearch/index/analysis/phonetic-1.yml

@@ -19,6 +19,10 @@ index:
       beidermorsefilter:
         type: phonetic
         encoder: beidermorse
+      beidermorsefilterfrench:
+        type: phonetic
+        encoder: beidermorse
+        languageset : [ "french" ]
       koelnerphonetikfilter:
         type: phonetic
         encoder: koelnerphonetik