From e13629a95a548144b335fdd175c7d5c31f1bc2d5 Mon Sep 17 00:00:00 2001
From: Toshiya Kobayashi <toshiyakobayashi@gmail.com>
Date: Tue, 4 Jun 2024 17:29:23 +0900
Subject: [PATCH] [incubator-kie-drools-5911] [new-parser] Support optional
 type keyword for backward compatibility (#5977)

---
 .../drools/drl/parser/antlr4/MiscDRLParserTest.java | 13 +++++++++++++
 .../org/drools/drl/parser/antlr4/DRL6Expressions.g4 |  1 +
 .../antlr4/org/drools/drl/parser/antlr4/DRLLexer.g4 |  1 +
 .../org/drools/drl/parser/antlr4/DRLParser.g4       |  2 +-
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/MiscDRLParserTest.java b/drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/MiscDRLParserTest.java
index d3a919d0c48..7057579d8d8 100644
--- a/drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/MiscDRLParserTest.java
+++ b/drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/MiscDRLParserTest.java
@@ -5327,4 +5327,17 @@ void functionWithAnonymousClass() {
                                                                            "        }\n" +
                                                                            "    };");
     }
+
+    @Test
+    void typeDeclarationWithTypeToken() {
+        final String drl = "declare type Foo\n" + // "type" is just optional
+                "  id : int\n" +
+                "end";
+        final PackageDescr pkg = parseAndGetPackageDescr(drl);
+
+        TypeDeclarationDescr typeDeclarationDescr = pkg.getTypeDeclarations().get(0);
+        assertThat(typeDeclarationDescr.getTypeName()).isEqualTo("Foo");
+        TypeFieldDescr typeFieldDescr = typeDeclarationDescr.getFields().get("id");
+        assertThat(typeFieldDescr.getPattern().getObjectType()).isEqualTo("int");
+    }
 }
diff --git a/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRL6Expressions.g4 b/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRL6Expressions.g4
index 026beef4cea..9819713fbb5 100644
--- a/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRL6Expressions.g4
+++ b/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRL6Expressions.g4
@@ -241,6 +241,7 @@ drlKeywords returns [Token token]
     | DRL_GLOBAL
     | DRL_DECLARE
     | DRL_TRAIT
+    | DRL_TYPE
     | DRL_RULE
     | DRL_QUERY
     | DRL_WHEN
diff --git a/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLLexer.g4 b/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLLexer.g4
index 5809147d651..198dfccfc2a 100644
--- a/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLLexer.g4
+++ b/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLLexer.g4
@@ -36,6 +36,7 @@ DRL_FUNCTION : 'function';
 DRL_GLOBAL : 'global';
 DRL_DECLARE : 'declare';
 DRL_TRAIT : 'trait';
+DRL_TYPE : 'type';
 DRL_RULE : 'rule';
 DRL_QUERY : 'query';
 DRL_WHEN : 'when';
diff --git a/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLParser.g4 b/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLParser.g4
index cabdaaa1f34..40b3bc66596 100644
--- a/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLParser.g4
+++ b/drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRLParser.g4
@@ -61,7 +61,7 @@ declaredef : DRL_DECLARE (
  *                     END
  */
 
-typeDeclaration : DRL_TRAIT? name=drlQualifiedName (EXTENDS superTypes+=drlQualifiedName (COMMA superTypes+=drlQualifiedName)* )? drlAnnotation* field* DRL_END ;
+typeDeclaration : DRL_TRAIT? DRL_TYPE? name=drlQualifiedName (EXTENDS superTypes+=drlQualifiedName (COMMA superTypes+=drlQualifiedName)* )? drlAnnotation* field* DRL_END ;
 
 // entryPointDeclaration := ENTRY-POINT stringId annotation* END