Remove `token_filter` in _analyze API

Remove the param and change docs

Closes #20283

core/src/main/java/org/elasticsearch/rest/action/admin/indices/RestAnalyzeAction.java

@@ -50,7 +50,7 @@ public class RestAnalyzeAction extends BaseRestHandler {
         public static final ParseField TEXT = new ParseField("text");
         public static final ParseField FIELD = new ParseField("field");
         public static final ParseField TOKENIZER = new ParseField("tokenizer");
-        public static final ParseField TOKEN_FILTERS = new ParseField("filter", "token_filter");
+        public static final ParseField TOKEN_FILTERS = new ParseField("filter");
         public static final ParseField CHAR_FILTERS = new ParseField("char_filter");
         public static final ParseField EXPLAIN = new ParseField("explain");
         public static final ParseField ATTRIBUTES = new ParseField("attributes");
@@ -77,7 +77,7 @@ public class RestAnalyzeAction extends BaseRestHandler {
         if (request.hasParam("tokenizer")) {
             analyzeRequest.tokenizer(request.param("tokenizer"));
         }
-        for (String filter : request.paramAsStringArray("filter", request.paramAsStringArray("token_filter", Strings.EMPTY_ARRAY))) {
+        for (String filter : request.paramAsStringArray("filter", Strings.EMPTY_ARRAY)) {
             analyzeRequest.addTokenFilter(filter);
         }
         for (String charFilter : request.paramAsStringArray("char_filter", Strings.EMPTY_ARRAY)) {
@@ -144,7 +144,7 @@ public class RestAnalyzeAction extends BaseRestHandler {
                                 analyzeRequest.addTokenFilter(parser.map());
                             } else {
                                 throw new IllegalArgumentException(currentFieldName
-                                        + " array element should contain token_filter's name or setting");
+                                        + " array element should contain filter's name or setting");
                             }
                         }
                     } else if (parseFieldMatcher.match(currentFieldName, Fields.CHAR_FILTERS)

core/src/test/java/org/elasticsearch/rest/action/admin/indices/RestAnalyzeActionTests.java

@@ -181,6 +181,21 @@ public class RestAnalyzeActionTests extends ESTestCase {
             assertThat(e.getMessage(), startsWith("Unknown parameter [char_filters]"));
         }
 
+        content =  XContentFactory.jsonBuilder()
+            .startObject()
+            .field("text", "THIS IS A TEST")
+            .field("tokenizer", "keyword")
+            .array("token_filter", "lowercase")
+            .endObject().bytes();
+
+        analyzeRequest = new AnalyzeRequest("for test");
+
+        try {
+            RestAnalyzeAction.buildFromContent(content, analyzeRequest, new ParseFieldMatcher(Settings.EMPTY));
+        } catch (Exception e) {
+            assertThat(e, instanceOf(IllegalArgumentException.class));
+            assertThat(e.getMessage(), startsWith("Unknown parameter [token_filter]"));
+        }
     }
 
 }

docs/reference/indices/analyze.asciidoc

@@ -43,13 +43,13 @@ curl -XGET 'localhost:9200/_analyze' -d '
 curl -XGET 'localhost:9200/_analyze' -d '
 {
   "tokenizer" : "keyword",
-  "token_filter" : ["lowercase"],
+  "filter" : ["lowercase"],
   "char_filter" : ["html_strip"],
   "text" : "this is a <b>test</b>"
 }'
 --------------------------------------------------
 
-deprecated[5.0.0, Use `filter`/`token_filter`/`char_filter` instead of `filters`/`token_filters`/`char_filters`]
+deprecated[5.0.0, Use `filter`/`char_filter` instead of `filters`/`char_filters` and `token_filters` has been removed]
 
 Custom tokenizers, token filters, and character filters can be specified in the request body as follows:
 
@@ -112,7 +112,7 @@ provided it doesn't start with `{` :
 
 [source,js]
 --------------------------------------------------
-curl -XGET 'localhost:9200/_analyze?tokenizer=keyword&token_filter=lowercase&char_filter=html_strip' -d 'this is a <b>test</b>'
+curl -XGET 'localhost:9200/_analyze?tokenizer=keyword&filter=lowercase&char_filter=html_strip' -d 'this is a <b>test</b>'
 --------------------------------------------------
 
 === Explain Analyze

docs/reference/migration/migrate_5_0/rest.asciidoc

@@ -67,8 +67,8 @@ removed in Elasticsearch 6.0.0.
 
 ==== Analyze API changes
 
-The deprecated `filters`/`token_filters`/`char_filters` parameter has been
-renamed `filter`/`token_filter`/`char_filter`.
+The deprecated `filters`/`char_filters` parameter has been
+renamed `filter`/`char_filter` and `token_filters` parameter has been removed.
 
 ==== `DELETE /_query` endpoint removed