How to make sure that whitelisted plugin for painless is working?

Hi
I have created a sample whitelist plugin for painless, so that i can use the whitelisted methods in my painless script.
i used the following guide to have custom hexdigest methods compiled in to plugin

Aim of the plugin is to whitelist hexdigest methods so that painless scripts get access, so there is one such example i followed

i have created something like below

i have installed plugin successfully and restarted the es successfully , logs displayed with the plugin i installed after i restarted.
But when i run search it gives me a exception.

curl -XGET -H "Content-Type: application/json"  http://localhost:9200/_search\?size\=10 -d '{"query":{"bool":{"filter":[{"range":{"meta_ts":{"gte":"2021-08-04T13:00:00.000Z","lte":"2021-08-23T13:51:35.698Z"}}},{"script":{"script":{"lang":"painless","source":"\n String convertedHexValue = null; def hd = new HexDigest(); String value = doc[params.field].value; String hex = (params.hex.length() % 2 == 0) ? params.hex : '0' + params.hex; if (value.length() > 0) { convertedHexValue = hd.getHexDigest(params.algorithm,value); } if (hex.equals(convertedHexValue)){ return true; } return false; \n ","params":{"field":"class","algorithm":"MD5","hex":"0449822057c99079dd9dc9818e300eaa"}}}}]}}}' | jq . | less

response form search

    "lang": "painless",
            "caused_by": {
              "type": "illegal_argument_exception",
              "reason": "invalid sequence of tokens near ['HexDigest'].",
              "caused_by": {
                "type": "no_viable_alt_exception",
                "reason": null

elastic search logs are

Caused by: org.antlr.v4.runtime.NoViableAltException
	at org.antlr.v4.runtime.atn.ParserATNSimulator.noViableAlt(ParserATNSimulator.java:1884) ~[?:?]
	at org.antlr.v4.runtime.atn.ParserATNSimulator.execATN(ParserATNSimulator.java:486) ~[?:?]
	at org.antlr.v4.runtime.atn.ParserATNSimulator.adaptivePredict(ParserATNSimulator.java:412) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.unary(PainlessParser.java:2056) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.expression(PainlessParser.java:1716) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.declvar(PainlessParser.java:1466) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.declaration(PainlessParser.java:1342) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.dstatement(PainlessParser.java:964) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.statement(PainlessParser.java:395) ~[?:?]
	at org.elasticsearch.painless.antlr.PainlessParser.source(PainlessParser.java:178) ~[?:?]
	at org.elasticsearch.painless.antlr.Walker.buildAntlrTree(Walker.java:222) ~[?:?]
	at org.elasticsearch.painless.antlr.Walker.<init>(Walker.java:204) ~[?:?]
	at org.elasticsearch.painless.antlr.Walker.buildPainlessTree(Walker.java:179) ~[?:?]
	at org.elasticsearch.painless.Compiler.compile(Compiler.java:211) ~[?:?]
	at org.elasticsearch.painless.PainlessScriptEngine$5.run(PainlessScriptEngine.java:420) ~[?:?]
	at org.elasticsearch.painless.PainlessScriptEngine$5.run(PainlessScriptEngine.java:416) ~[?:?]
	at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_271]
	at org.elasticsearch.painless.PainlessScriptEngine.compile(PainlessScriptEngine.java:416) ~[?:?]
	at org.elasticsearch.painless.PainlessScriptEngine.compile(PainlessScriptEngine.java:167) ~[?:?]
	at org.elasticsearch.script.ScriptService.compile(ScriptService.java:363) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.ScriptQueryBuilder.doToQuery(ScriptQueryBuilder.java:135) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.AbstractQueryBuilder.toQuery(AbstractQueryBuilder.java:106) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.AbstractQueryBuilder.toFilter(AbstractQueryBuilder.java:128) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.BoolQueryBuilder.addBooleanClauses(BoolQueryBuilder.java:419) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.BoolQueryBuilder.doToQuery(BoolQueryBuilder.java:386) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.AbstractQueryBuilder.toQuery(AbstractQueryBuilder.java:106) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.QueryShardContext.lambda$toQuery$2(QueryShardContext.java:319) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.QueryShardContext.toQuery(QueryShardContext.java:331) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.index.query.QueryShardContext.toQuery(QueryShardContext.java:318) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService.parseSource(SearchService.java:806) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService.createContext(SearchService.java:653) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService.createAndPutContext(SearchService.java:604) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:388) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService.access$100(SearchService.java:127) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService$2.onResponse(SearchService.java:360) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService$2.onResponse(SearchService.java:356) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.search.SearchService$4.doRun(SearchService.java:1129) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.common.util.concurrent.TimedRunnable.doRun(TimedRunnable.java:41) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:778) ~[elasticsearch-6.8.18.jar:6.8.18]
	at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) ~[elasticsearch-6.8.18.jar:6.8.18]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[?:1.8.0_271]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[?:1.8.0_271]
	at java.lang.Thread.run(Thread.java:748) ~[?:1.8.0_271]

can someone please let me know if the plugin is right or wrong?

Hi Gowtham!

This looks really close to me. I believe the issue is with the context the whitelist is applied to. For a filter query it actually uses a different context than search. If you instead change it to add this whitelist to FilterScript.CONTEXT in the WhitelistExtention class that should fix this issue.

As a side note the error you received indicates that the type wasn't found as part of that script. We have improved this error message in newer versions of Elasticsearch that would tell you symbol not found instead of a grammar exception with little information.

Please let me know if this fixes the issue. Thank you!

thanks @Jack_Conradson
i had issues with plugin generation and i missed the FilterScript.context as u mentioned.
I have rectified both and it works as expected