Scripts: Convert template script engines to return String instead of BytesReference (#24447)

Template script engines (mustache, the only one) currently return a
BytesReference that users must know is utf8 encoded. This commit
modifies all callers and mustache to have the template engine return
String. This is much simpler, and does not require decoding in order to
use (for example, in ingest).

1 files changed, 3 insertions, 3 deletions

diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/TransportSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/TransportSearchTemplateAction.java
index 8c3e013591..a2a9dd8b47 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/TransportSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/TransportSearchTemplateAction.java
@@ -26,6 +26,7 @@ import org.elasticsearch.action.search.TransportSearchAction;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.HandledTransportAction;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
@@ -102,11 +103,10 @@ public class TransportSearchTemplateAction extends HandledTransportAction<Search
         Script script = new Script(searchTemplateRequest.getScriptType(), TEMPLATE_LANG, searchTemplateRequest.getScript(),
                 searchTemplateRequest.getScriptParams() == null ? Collections.emptyMap() : searchTemplateRequest.getScriptParams());
         CompiledTemplate compiledScript = scriptService.compileTemplate(script, SEARCH);
-        BytesReference source = compiledScript.run(script.getParams());
-        response.setSource(source);
+        String source = compiledScript.run(script.getParams());
+        response.setSource(new BytesArray(source));
 
         SearchRequest searchRequest = searchTemplateRequest.getRequest();
-        response.setSource(source);
         if (searchTemplateRequest.isSimulate()) {
             return null;
         }