Merge pull request #284 from pzygielo/message

Fix NullPointerException on null outcome

impl/src/main/java/org/glassfish/soteria/cdi/AnnotationELPProcessor.java

@@ -51,10 +51,13 @@ public static boolean evalImmediate(ELProcessor getELProcessor, String expressio
         if (outcome instanceof Boolean) {
             return (Boolean) outcome;
         }
-
-        throw new IllegalStateException(
-            "Expression " + expression + " should evaluate to boolean but evaluated to " +
-             outcome == null? " null" : (outcome.getClass() + " " + outcome));
+
+        throw new IllegalStateException(buildNonBooleanOutcomeMessage(outcome, expression));
+    }
+
+    static String buildNonBooleanOutcomeMessage(Object outcome, String expression) {
+        return "Expression " + expression + " should evaluate to boolean but evaluated to " +
+             (outcome == null? " null" : (outcome.getClass() + " " + outcome));
     }
 
     public static int evalImmediate(String expression, int defaultValue) {

impl/src/test/java/org/glassfish/soteria/cdi/AnnotationELPProcessorTest.java

@@ -0,0 +1,22 @@
+package org.glassfish.soteria.cdi;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+
+public class AnnotationELPProcessorTest {
+  @Test
+  public void shouldBuildExpectedMessageForNullOutcome() {
+    String msg = AnnotationELPProcessor.buildNonBooleanOutcomeMessage(null, "abc");
+
+    assertEquals("Expression abc should evaluate to boolean but evaluated to  null", msg);
+  }
+
+  @Test
+  public void shouldBuildExpectedMessageForNonBooleanOutcome() {
+    String msg = AnnotationELPProcessor.buildNonBooleanOutcomeMessage(1, "ijk");
+
+    assertEquals("Expression ijk should evaluate to boolean but evaluated to class java.lang.Integer 1", msg);
+  }
+
+}
+