add antlr version

Signed-off-by: Eric Wei <mengwei.eric@gmail.com>

Author: mengweieric

plugin/src/main/java/org/opensearch/sql/plugin/rest/RestPPLGrammarAction.java

@@ -91,6 +91,7 @@ private void serializeBundle(XContentBuilder builder, GrammarBundle bundle) thro
 
     // Identity & versioning
     builder.field("bundleVersion", bundle.getBundleVersion());
+    builder.field("antlrVersion", bundle.getAntlrVersion());
     builder.field("grammarHash", bundle.getGrammarHash());
     builder.field("startRuleIndex", bundle.getStartRuleIndex());
 

plugin/src/test/java/org/opensearch/sql/plugin/rest/RestPPLGrammarActionTest.java

@@ -68,6 +68,7 @@ public void testGetGrammar_ReturnsBundle() throws Exception {
 
     String content = response.content().utf8ToString();
     assertTrue(content.contains("\"bundleVersion\":\"1.0\""));
+    assertTrue(content.contains("\"antlrVersion\":"));
     assertTrue(content.contains("\"grammarHash\":\"sha256:"));
     assertTrue(content.contains("\"startRuleIndex\":0"));
     assertTrue(content.contains("\"lexerSerializedATN\":"));

ppl/src/main/java/org/opensearch/sql/ppl/autocomplete/GrammarBundle.java

@@ -17,6 +17,9 @@ public class GrammarBundle {
   /** Bundle format version. */
   @NonNull private String bundleVersion;
 
+  /** ANTLR runtime version used to generate the grammar. */
+  @NonNull private String antlrVersion;
+
   /** SHA-256 hash of the serialized ATN data. Clients may use this to detect grammar changes. */
   @NonNull private String grammarHash;
 

ppl/src/main/java/org/opensearch/sql/ppl/autocomplete/PPLGrammarBundleBuilder.java

@@ -45,6 +45,7 @@ public GrammarBundle build() {
 
     return GrammarBundle.builder()
         .bundleVersion(BUNDLE_VERSION)
+        .antlrVersion(ANTLR_VERSION)
         .grammarHash(computeGrammarHash(lexerATN, parserATN))
         .lexerSerializedATN(lexerATN)
         .parserSerializedATN(parserATN)