Minor cleanup of constant check

Signed-off-by: Pablo Herrera <[email protected]>

core/src/main/java/tc/oc/pgm/map/ConditionalChecker.java

@@ -24,7 +24,7 @@ class ConditionalChecker {
    *
    * @param ctx the map's context
    * @param el The conditional element
-   * @return true if the conditional
+   * @return if the conditional passes
    * @throws InvalidXMLException if the element is invalid in any way
    */
   static boolean test(MapFilePreprocessor ctx, Element el) throws InvalidXMLException {
@@ -63,31 +63,29 @@ private static boolean constant(MapFilePreprocessor ctx, Element el, String id)
         value == null ? Cmp.DEFINED : Cmp.EQUALS);
 
     var constants = ctx.getConstants();
+    var isDefined = constants.containsKey(id);
+    var constant = isDefined ? constants.get(id) : null;
 
     if (!cmp.requireValue) {
       if (value != null)
         throw new InvalidXMLException("Comparison type " + cmp + " should not have a value", value);
 
-      if (!constants.containsKey(id)) return cmp == Cmp.UNDEFINED;
-
       return switch (cmp) {
-        case DEFINED -> true;
-        case DEFINED_DELETE -> constants.get(id) == null;
-        case DEFINED_VALUE -> constants.get(id) != null;
+        case UNDEFINED -> !isDefined;
+        case DEFINED -> isDefined;
+        case DEFINED_DELETE -> isDefined && constant == null;
+        case DEFINED_VALUE -> isDefined && constant != null;
           // Should never happen
         default -> throw new IllegalStateException(cmp + " not supported");
       };
     } else {
-      String constant = constants.get(id);
-      if (constant == null) {
-        if (!constants.containsKey(id))
-          throw new InvalidXMLException(
-              "Unknown constant '" + id + "'. Only constants before the conditional may be used.",
-              el);
-        return false;
-      }
+      if (!isDefined)
+        throw new InvalidXMLException(
+            "Unknown constant '" + id + "'. Only constants before the conditional may be used.",
+            el);
       if (value == null)
         throw new InvalidXMLException("Required attribute 'constant-value' not set", el);
+      if (constant == null) return false;
 
       return switch (cmp) {
         case EQUALS -> Objects.equals(value.getValue(), constant);