Add support for parser context in MVEL actions

Resolves #197

easy-rules-mvel/src/main/java/org/jeasy/rules/mvel/MVELAction.java

@@ -26,6 +26,7 @@ package org.jeasy.rules.mvel;
 import org.jeasy.rules.api.Action;
 import org.jeasy.rules.api.Facts;
 import org.mvel2.MVEL;
+import org.mvel2.ParserContext;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -53,6 +54,17 @@ public class MVELAction implements Action {
         compiledExpression = MVEL.compileExpression(expression);
     }
 
+    /**
+     * Create a new {@link MVELAction}.
+     *
+     * @param expression the action written in expression language
+     * @param parserContext the MVEL parser context
+     */
+    public MVELAction(String expression, ParserContext parserContext) {
+        this.expression = expression;
+        compiledExpression = MVEL.compileExpression(expression, parserContext);
+    }
+
     @Override
     public void execute(Facts facts) {
         try {

easy-rules-mvel/src/test/java/org/jeasy/rules/mvel/MVELActionTest.java

@@ -29,6 +29,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.contrib.java.lang.system.SystemOutRule;
 import org.junit.rules.ExpectedException;
+import org.mvel2.ParserContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -84,4 +85,20 @@ public class MVELActionTest {
         // then
         // excepted exception
     }
+
+    @Test
+    public void testMVELActionWithExpressionAndParserContext() throws Exception {
+        // given
+        ParserContext context = new ParserContext();
+        context.addPackageImport("java.util");
+        Action printAction = new MVELAction("def random() { System.out.println(\"Random from MVEL = \" + new java.util.Random(123).nextInt(10)); }; random();", context);
+        Facts facts = new Facts();
+
+        // when
+        printAction.execute(facts);
+
+        // then
+        assertThat(systemOutRule.getLog()).contains("Random from MVEL = 2");
+
+    }
 }