Deprecate unicodeSetFilter in favour of unicode_set_filter (#29215)

Author: Ke Li

docs/plugins/analysis-icu.asciidoc

@@ -38,7 +38,7 @@ normalization can be specified with the `name` parameter, which accepts `nfc`,
 convert `nfc` to `nfd` or `nfkc` to `nfkd` respectively:
 
 Which letters are normalized can be controlled by specifying the
-`unicodeSetFilter` parameter, which accepts a
+`unicode_set_filter` parameter, which accepts a
 http://icu-project.org/apiref/icu4j/com/ibm/icu/text/UnicodeSet.html[UnicodeSet].
 
 Here are two examples, the default usage and a customised character filter:
@@ -194,7 +194,7 @@ with the `name` parameter, which accepts `nfc`, `nfkc`, and `nfkc_cf`
 (default).
 
 Which letters are normalized can be controlled by specifying the
-`unicodeSetFilter` parameter, which accepts a
+`unicode_set_filter` parameter, which accepts a
 http://icu-project.org/apiref/icu4j/com/ibm/icu/text/UnicodeSet.html[UnicodeSet].
 
 You should probably prefer the <<analysis-icu-normalization-charfilter,Normalization character filter>>.
@@ -273,7 +273,7 @@ The ICU folding token filter already does Unicode normalization, so there is
 no need to use Normalize character or token filter as well.
 
 Which letters are folded can be controlled by specifying the
-`unicodeSetFilter` parameter, which accepts a
+`unicode_set_filter` parameter, which accepts a
 http://icu-project.org/apiref/icu4j/com/ibm/icu/text/UnicodeSet.html[UnicodeSet].
 
 The following example exempts Swedish characters from folding. It is important
@@ -300,7 +300,7 @@ PUT icu_sample
         "filter": {
           "swedish_folding": {
             "type": "icu_folding",
-            "unicodeSetFilter": "[^åäöÅÄÖ]"
+            "unicode_set_filter": "[^åäöÅÄÖ]"
           }
         }
       }

plugins/analysis-icu/src/main/java/org/elasticsearch/index/analysis/IcuFoldingTokenFilterFactory.java

@@ -50,7 +50,7 @@ public class IcuFoldingTokenFilterFactory extends AbstractTokenFilterFactory imp
 
     public IcuFoldingTokenFilterFactory(IndexSettings indexSettings, Environment environment, String name, Settings settings) {
         super(indexSettings, name, settings);
-        this.normalizer = IcuNormalizerTokenFilterFactory.wrapWithUnicodeSetFilter(ICU_FOLDING_NORMALIZER, settings);
+        this.normalizer = IcuNormalizerTokenFilterFactory.wrapWithUnicodeSetFilter(indexSettings, ICU_FOLDING_NORMALIZER, settings);
     }
 
     @Override

plugins/analysis-icu/src/main/java/org/elasticsearch/index/analysis/IcuNormalizerCharFilterFactory.java

@@ -49,7 +49,7 @@ public IcuNormalizerCharFilterFactory(IndexSettings indexSettings, Environment e
         }
         Normalizer2 normalizer = Normalizer2.getInstance(
             null, method, "compose".equals(mode) ? Normalizer2.Mode.COMPOSE : Normalizer2.Mode.DECOMPOSE);
-        this.normalizer = IcuNormalizerTokenFilterFactory.wrapWithUnicodeSetFilter(normalizer, settings);
+        this.normalizer = IcuNormalizerTokenFilterFactory.wrapWithUnicodeSetFilter(indexSettings, normalizer, settings);
     }
 
     @Override

plugins/analysis-icu/src/main/java/org/elasticsearch/index/analysis/IcuNormalizerTokenFilterFactory.java

@@ -23,7 +23,10 @@
 import com.ibm.icu.text.Normalizer2;
 import com.ibm.icu.text.UnicodeSet;
 
+import org.apache.logging.log4j.LogManager;
 import org.apache.lucene.analysis.TokenStream;
+import org.elasticsearch.Version;
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
@@ -35,14 +38,15 @@
  * <p>The {@code unicodeSetFilter} attribute can be used to provide the UniCodeSet for filtering.</p>
  */
 public class IcuNormalizerTokenFilterFactory extends AbstractTokenFilterFactory implements MultiTermAwareComponent {
-
+    private final static DeprecationLogger deprecationLogger =
+        new DeprecationLogger(LogManager.getLogger(IcuNormalizerTokenFilterFactory.class));
     private final Normalizer2 normalizer;
 
     public IcuNormalizerTokenFilterFactory(IndexSettings indexSettings, Environment environment, String name, Settings settings) {
         super(indexSettings, name, settings);
         String method = settings.get("name", "nfkc_cf");
         Normalizer2 normalizer = Normalizer2.getInstance(null, method, Normalizer2.Mode.COMPOSE);
-        this.normalizer = wrapWithUnicodeSetFilter(normalizer, settings);
+        this.normalizer = wrapWithUnicodeSetFilter(indexSettings, normalizer, settings);
     }
 
     @Override
@@ -55,8 +59,17 @@ public Object getMultiTermComponent() {
         return this;
     }
 
-    static Normalizer2 wrapWithUnicodeSetFilter(final Normalizer2 normalizer, Settings settings) {
+    static Normalizer2 wrapWithUnicodeSetFilter(final IndexSettings indexSettings,
+                                                final Normalizer2 normalizer,
+                                                final Settings settings) {
         String unicodeSetFilter = settings.get("unicodeSetFilter");
+        if (indexSettings.getIndexVersionCreated().onOrAfter(Version.V_7_0_0_alpha1)) {
+            if (unicodeSetFilter != null) {
+                deprecationLogger.deprecated("[unicodeSetFilter] has been deprecated in favor of [unicode_set_filter]");
+            } else {
+                unicodeSetFilter = settings.get("unicode_set_filter");
+            }
+        }
         if (unicodeSetFilter != null) {
             UnicodeSet unicodeSet = new UnicodeSet(unicodeSetFilter);
 

plugins/analysis-icu/src/test/resources/rest-api-spec/test/analysis_icu/10_basic.yml

@@ -48,6 +48,61 @@
 ---
 "Normalization with a UnicodeSet Filter":
     - do:
+        indices.create:
+            index:  test
+            body:
+                settings:
+                    index:
+                        analysis:
+                            char_filter:
+                                charfilter_icu_normalizer:
+                                    type: icu_normalizer
+                                    unicode_set_filter: "[^ß]"
+                            filter:
+                                tokenfilter_icu_normalizer:
+                                    type: icu_normalizer
+                                    unicode_set_filter: "[^ßB]"
+                                tokenfilter_icu_folding:
+                                    type: icu_folding
+                                    unicode_set_filter: "[^â]"
+    - do:
+        indices.analyze:
+          index:    test
+          body:
+            char_filter: ["charfilter_icu_normalizer"]
+            tokenizer:  keyword
+            text:     charfilter Föo Bâr Ruß
+    - length: { tokens: 1 }
+    - match:  { tokens.0.token: charfilter föo bâr ruß }
+    - do:
+        indices.analyze:
+          index:    test
+          body:
+            tokenizer:  keyword
+            filter: ["tokenfilter_icu_normalizer"]
+            text:     tokenfilter Föo Bâr Ruß
+    - length: { tokens: 1 }
+    - match:  { tokens.0.token: tokenfilter föo Bâr ruß }
+    - do:
+        indices.analyze:
+          index:    test
+          body:
+            tokenizer:  keyword
+            filter: ["tokenfilter_icu_folding"]
+            text:     icufolding Föo Bâr Ruß
+    - length: { tokens: 1 }
+    - match:  { tokens.0.token: icufolding foo bâr russ }
+
+---
+"Normalization with a CamcelCase UnicodeSet Filter":
+    - skip:
+        version: " - 6.99.99"
+        reason:  unicodeSetFilter deprecated in 7.0.0, replaced by unicode_set_filter
+        features: "warnings"
+
+    - do:
+        warnings:
+          - "[unicodeSetFilter] has been deprecated in favor of [unicode_set_filter]"
         indices.create:
             index:  test
             body: