Make EnclosedExpr.inner required

2 files changed, 10 insertions, 8 deletions

diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java
index 0f6de4056..acfb2b6c5 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java
@@ -82,6 +82,9 @@ public final class EnclosedExpr extends Expression {
      */
     @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
     public EnclosedExpr setInner(final Expression inner) {
+        if(inner==null){
+            throw new AssertionError();
+        }
         if (inner == this.inner) {
             return (EnclosedExpr) this;
         }
diff --git a/javaparser-core/src/main/javacc/java.jj b/javaparser-core/src/main/javacc/java.jj
index 83ebf41d3..9e91c6b85 100644
--- a/javaparser-core/src/main/javacc/java.jj
+++ b/javaparser-core/src/main/javacc/java.jj
@@ -1899,15 +1899,14 @@ Expression PrimaryPrefix():
 		}
 	  )
 	|
-	  "(" {begin=token();}
-	  	[
-            ( LOOKAHEAD(Parameter())
-                p = Parameter() { isLambda = true;} [params = LambdaParameters()]
+        "(" {begin=token();}
+        (
+            ")" { ret = new LambdaExpr(range(begin, token()), params, new BlockStmt(), true); }
+            | LOOKAHEAD(Parameter())
+            p = Parameter() { isLambda = true;} [params = LambdaParameters()] ")"
             |
-                ret = Expression() [params = InferredLambdaParameters() { isLambda = true;} ]
-            )
-	  	]
-	  	")"
+            ret = Expression() [params = InferredLambdaParameters() { isLambda = true;} ] ")"
+        )
         {
             if(!isLambda) { 
                 ret = new EnclosedExpr(range(begin, token()), ret);