[KIE-978] fix generation of expression binding in executable model (#…

…5749)

drools-model/drools-model-codegen/src/main/java/org/drools/model/codegen/execmodel/generator/OOPathExprGenerator.java

@@ -199,7 +199,7 @@ private void toPatternExpr(String bindingId, List<DrlxParseResult> list, DrlxPar
                     expr.setScope( patternExpr );
                     patternExpr = expr;
                 }
-                if (singleDrlx.getExpr() != null && !(singleDrlx.getExpr() instanceof NameExpr)) {
+                if (singleDrlx.getExpr() != null && singleDrlx.isPredicate()) {
                     MethodCallExpr expr = expressionBuilder.buildExpressionWithIndexing( singleDrlx );
                     expr.setScope( patternExpr );
                     patternExpr = expr;

drools-model/drools-model-codegen/src/main/java/org/drools/model/codegen/execmodel/generator/drlxparse/ConstraintParser.java

@@ -506,21 +506,23 @@ private DrlxParseResult parseNameExpr(DrlNameExpr nameExpr, Class<?> patternType
         Expression withThis = DrlxParseUtil.prepend(new NameExpr(THIS_PLACEHOLDER), converted.getExpression());
 
         if (hasBind) {
-            return new SingleDrlxParseSuccess(patternType, bindingId, null, converted.getType() )
+            return new SingleDrlxParseSuccess(patternType, bindingId, withThis, converted.getType() )
                     .setLeft( new TypedExpression( withThis, converted.getType() ) )
                     .addReactOnProperty( lcFirstForBean(nameExpr.getNameAsString()) );
-        } else if (context.hasDeclaration( expression )) {
+        }
+
+        if (context.hasDeclaration( expression )) {
             Optional<TypedDeclarationSpec> declarationSpec = context.getTypedDeclarationById(expression);
             if (declarationSpec.isPresent()) {
                 return new SingleDrlxParseSuccess(patternType, bindingId, context.getVarExpr(printNode(drlxExpr)), declarationSpec.get().getDeclarationClass() ).setIsPredicate(true);
             } else {
                 throw new IllegalArgumentException("Cannot find declaration specification by specified expression " + expression + "!");
             }
-        } else {
-            return new SingleDrlxParseSuccess(patternType, bindingId, withThis, converted.getType() )
-                    .addReactOnProperty( nameExpr.getNameAsString() )
-                    .setIsPredicate(true);
         }
+
+        return new SingleDrlxParseSuccess(patternType, bindingId, withThis, converted.getType() )
+                .addReactOnProperty( nameExpr.getNameAsString() )
+                .setIsPredicate(true);
     }
 
     private DrlxParseResult parseFieldAccessExpr( FieldAccessExpr fieldCallExpr, Class<?> patternType, String bindingId ) {

drools-model/drools-model-codegen/src/test/java/org/drools/model/codegen/execmodel/ConstraintTest.java

@@ -0,0 +1,90 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.drools.model.codegen.execmodel;
+
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.drools.model.codegen.execmodel.domain.Person;
+import org.junit.Before;
+import org.junit.Test;
+import org.kie.api.runtime.KieSession;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ConstraintTest extends BaseModelTest {
+
+    private static final String RULE_STRING = "package constraintexpression\n" +
+            "\n" +
+            "import " + Person.class.getCanonicalName() + "\n" +
+            "import java.util.List; \n" +
+            "import java.math.BigDecimal; \n" +
+            "global List<BigDecimal> bigDecimalListGlobal; \n" +
+            "rule \"r1\"\n" +
+            "when \n" +
+            "    $p : Person($amount: (money == null ? BigDecimal.valueOf(100.0) : money))\n" +
+            "then \n" +
+            "    System.out.println($amount); \n" +
+            "    System.out.println($p); \n" +
+            "    bigDecimalListGlobal.add($amount); \n " +
+            "end \n";
+
+    private KieSession ksession;
+
+    private List<BigDecimal> bigDecimalListGlobal;
+
+    public ConstraintTest(RUN_TYPE testRunType) {
+        super(testRunType);
+    }
+
+    @Before
+    public void setup() {
+        ksession = getKieSession(RULE_STRING);
+        bigDecimalListGlobal = new ArrayList<>();
+        ksession.setGlobal("bigDecimalListGlobal", bigDecimalListGlobal);
+    }
+
+    @Test
+    public void testConstraintWithMoney() {
+        try {
+            BigDecimal money = BigDecimal.valueOf(34.45);
+            Person person = new Person("", money);
+            ksession.insert(person);
+            int rulesFired = ksession.fireAllRules();
+            assertThat(rulesFired).isEqualTo(1);
+            assertThat(bigDecimalListGlobal).isNotEmpty().containsExactly(money);
+        } finally {
+            ksession.dispose();
+        }
+    }
+
+    @Test
+    public void testConstraintWithoutMoney() {
+        try {
+            Person person = new Person();
+            ksession.insert(person);
+            int rulesFired = ksession.fireAllRules();
+            assertThat(rulesFired).isEqualTo(1);
+            assertThat(bigDecimalListGlobal).isNotEmpty().containsExactly(BigDecimal.valueOf(100.0));
+        } finally {
+            ksession.dispose();
+        }
+    }
+}