[incubator-kie-drools-5932] [new-parser] Anonymous classes not supported

drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/MiscDRLParserTest.java

@@ -5304,4 +5304,27 @@ void accumulateWithEmptyActionAndReverse() {
             });
         });
     }
+
+    @Test
+    void functionWithAnonymousClass() {
+        final String text = "function Function<String, Integer> f() {\n" +
+                "    return new Function<String, Integer>() {\n" +
+                "        public Integer apply(String s) {\n" +
+                "            return s.length();\n" +
+                "        }\n" +
+                "    };\n" +
+                "}";
+        PackageDescr packageDescr = parseAndGetPackageDescr(text);
+        FunctionDescr function = packageDescr.getFunctions().get(0);
+
+        assertThat(function.getName()).isEqualTo("f");
+        assertThat(function.getReturnType()).isEqualToIgnoringWhitespace("Function<String, Integer>");
+        assertThat(function.getParameterTypes()).isEmpty();
+        assertThat(function.getParameterNames()).isEmpty();
+        assertThat(function.getBody()).isEqualToIgnoringWhitespace("return new Function<String, Integer>() {\n" +
+                                                                           "        public Integer apply(String s) {\n" +
+                                                                           "            return s.length();\n" +
+                                                                           "        }\n" +
+                                                                           "    };");
+    }
 }

drools-drl/drools-drl-parser/src/main/antlr4/org/drools/drl/parser/antlr4/DRL6Expressions.g4

@@ -810,7 +810,7 @@ identifierSuffix
 
 creator
     :	nonWildcardTypeArguments? createdName
-        (arrayCreatorRest | classCreatorRest)
+        (arrayCreatorRest | classCreatorRestExpr)
     ;
 
 createdName
@@ -821,7 +821,7 @@ createdName
 
 // Old parser cannot parse innerCreator with selector expression (outer.new InnerClass() != null) TODO: Delete this after investigation
 innerCreator
-    :	{!(helper.validateIdentifierKey(DroolsSoftKeywords.INSTANCEOF))}? drlIdentifier classCreatorRest
+    :	{!(helper.validateIdentifierKey(DroolsSoftKeywords.INSTANCEOF))}? drlIdentifier classCreatorRestExpr
     ;
 
 arrayCreatorRest
@@ -840,7 +840,7 @@ arrayInitializer
     :	LBRACE (variableInitializer (COMMA variableInitializer)* (COMMA)? )? RBRACE
     ;
 
-classCreatorRest
+classCreatorRestExpr // do not overwrite JavaParser.g4 classCreatorRest
     :	arguments //classBody?		//sotty:  restored classBody to allow for inline, anonymous classes
     ;
 

drools-drl/drools-drl-parser/src/main/java/org/drools/drl/parser/antlr4/DRLVisitorImpl.java

@@ -207,7 +207,7 @@ public FunctionDescr visitFunctiondef(DRLParser.FunctiondefContext ctx) {
                 .withParserRuleContext(ctx)
                 .build();
         if (ctx.typeTypeOrVoid() != null) {
-            functionDescr.setReturnType(ctx.typeTypeOrVoid().getText());
+            functionDescr.setReturnType(getTextPreservingWhitespace(ctx.typeTypeOrVoid()));
         } else {
             functionDescr.setReturnType("void");
         }