String distance algorithms cleanup

core/src/main/java/org/elasticsearch/search/suggest/phrase/DirectCandidateGeneratorBuilder.java

@@ -464,19 +464,13 @@ private static SuggestMode resolveSuggestMode(String suggestMode) {
     }
 
     static StringDistance resolveDistance(String distanceVal) {
-        distanceVal = distanceVal.toLowerCase(Locale.US);
+        distanceVal = distanceVal.toLowerCase(Locale.ROOT);
         if ("internal".equals(distanceVal)) {
             return DirectSpellChecker.INTERNAL_LEVENSHTEIN;
-        } else if ("damerau_levenshtein".equals(distanceVal) || "damerauLevenshtein".equals(distanceVal)) {
+        } else if ("damerau_levenshtein".equals(distanceVal)) {
             return new LuceneLevenshteinDistance();
-        } else if ("levenstein".equals(distanceVal)) {
-            DEPRECATION_LOGGER.deprecated("Deprecated distance [levenstein] used, replaced by [levenshtein]");
-            return new LevensteinDistance();
         } else if ("levenshtein".equals(distanceVal)) {
             return new LevensteinDistance();
-        } else if ("jarowinkler".equals(distanceVal)) {
-            DEPRECATION_LOGGER.deprecated("Deprecated distance [jarowinkler] used, replaced by [jaro_winkler]");
-            return new JaroWinklerDistance();
         } else if ("jaro_winkler".equals(distanceVal)) {
             return new JaroWinklerDistance();
         } else if ("ngram".equals(distanceVal)) {

core/src/main/java/org/elasticsearch/search/suggest/term/TermSuggestionBuilder.java

@@ -581,23 +581,16 @@ public static StringDistanceImpl readFromStream(final StreamInput in) throws IOE
 
         public static StringDistanceImpl resolve(final String str) {
             Objects.requireNonNull(str, "Input string is null");
-            final String distanceVal = str.toLowerCase(Locale.US);
+            final String distanceVal = str.toLowerCase(Locale.ROOT);
             switch (distanceVal) {
                 case "internal":
                     return INTERNAL;
                 case "damerau_levenshtein":
-                case "damerauLevenshtein":
                     return DAMERAU_LEVENSHTEIN;
-                case "levenstein":
-                    DEPRECATION_LOGGER.deprecated("Deprecated distance [levenstein] used, replaced by [levenshtein]");
-                    return LEVENSHTEIN;
                 case "levenshtein":
                     return LEVENSHTEIN;
                 case "ngram":
                     return NGRAM;
-                case "jarowinkler":
-                    DEPRECATION_LOGGER.deprecated("Deprecated distance [jarowinkler] used, replaced by [jaro_winkler]");
-                    return JARO_WINKLER;
                 case "jaro_winkler":
                     return JARO_WINKLER;
                 default: throw new IllegalArgumentException("Illegal distance option " + str);

core/src/test/java/org/elasticsearch/search/suggest/phrase/DirectCandidateGeneratorTests.java

@@ -83,16 +83,6 @@ public void testFromString() {
         expectThrows(NullPointerException.class, () -> DirectCandidateGeneratorBuilder.resolveDistance(null));
     }
 
-    public void testLevensteinDeprecation() {
-        assertThat(DirectCandidateGeneratorBuilder.resolveDistance("levenstein"), instanceOf(LevensteinDistance.class));
-        assertWarnings("Deprecated distance [levenstein] used, replaced by [levenshtein]");
-    }
-
-    public void testJaroWinklerDeprecation() {
-        assertThat(DirectCandidateGeneratorBuilder.resolveDistance("jaroWinkler"), instanceOf(JaroWinklerDistance.class));
-        assertWarnings("Deprecated distance [jarowinkler] used, replaced by [jaro_winkler]");
-    }
-
     private static DirectCandidateGeneratorBuilder mutate(DirectCandidateGeneratorBuilder original) throws IOException {
         DirectCandidateGeneratorBuilder mutation = copy(original);
         List<Supplier<DirectCandidateGeneratorBuilder>> mutators = new ArrayList<>();

core/src/test/java/org/elasticsearch/search/suggest/term/StringDistanceImplTests.java

@@ -58,16 +58,6 @@ public void testFromString() {
         assertThat(e.getMessage(), equalTo("Input string is null"));
     }
 
-    public void testLevensteinDeprecation() {
-        assertThat(StringDistanceImpl.resolve("levenstein"), equalTo(StringDistanceImpl.LEVENSHTEIN));
-        assertWarnings("Deprecated distance [levenstein] used, replaced by [levenshtein]");
-    }
-
-    public void testJaroWinklerDeprecation() {
-        assertThat(StringDistanceImpl.resolve("jaroWinkler"), equalTo(StringDistanceImpl.JARO_WINKLER));
-        assertWarnings("Deprecated distance [jarowinkler] used, replaced by [jaro_winkler]");
-    }
-
     @Override
     public void testWriteTo() throws IOException {
         assertWriteToStream(StringDistanceImpl.INTERNAL, 0);
@@ -85,5 +75,4 @@ public void testReadFrom() throws IOException {
         assertReadFromStream(3, StringDistanceImpl.JARO_WINKLER);
         assertReadFromStream(4, StringDistanceImpl.NGRAM);
     }
-
 }

docs/reference/migration/migrate_7_0/search.asciidoc

@@ -35,8 +35,17 @@ The Search API returns `400 - Bad request` while it would previously return
 *   number of filters in the adjacency matrix aggregation is too large
 
 
-==== Scroll queries cannot use the request_cache anymore
+==== Scroll queries cannot use the `request_cache` anymore
 
-Setting `request_cache:true` on a query that creates a scroll ('scroll=1m`)
+Setting `request_cache:true` on a query that creates a scroll (`scroll=1m`)
 has been deprecated in 6 and will now return a `400 - Bad request`.
 Scroll queries are not meant to be cached.
+
+==== Term Suggesters supported distance algorithms
+
+The following string distance algorithms were given additional names in 6.2 and
+their existing names were deprecated. The deprecated names have now been
+removed.
+
+* 	`levenstein` - replaced by `levenshtein`
+* 	`jarowinkler` - replaced by `jaro_winkler`