2 files changed, 14 insertions, 6 deletions
diff --git a/chapter17/src/test/java/com/seaofnodes/simple/Chapter13Test.java b/chapter17/src/test/java/com/seaofnodes/simple/Chapter13Test.java
index 30d9b147..eeb28f1d 100644
--- a/chapter17/src/test/java/com/seaofnodes/simple/Chapter13Test.java
+++ b/chapter17/src/test/java/com/seaofnodes/simple/Chapter13Test.java
@@ -130,6 +130,19 @@ return n.i;
     }
 
     @Test
+    public void testNullRef4() {
+        Parser parser = new Parser("-null-5/null-5;");
+        try { parser.parse().iterate(); fail(); }
+        catch( Exception e ) { assertEquals("Cannot 'Add' null",e.getMessage()); }
+    }
+
+    @Test public void testNullRef5() {
+        Parser parser = new Parser("return null+42;");
+        try { parser.parse().iterate(); fail(); }
+        catch( Exception e ) { assertEquals("Cannot 'Add' null",e.getMessage()); }
+    }
+
+    @Test
     public void testEmpty() {
         Parser parser = new Parser(
 """
diff --git a/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java b/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
index 4a7e959a..1ca9a515 100644
--- a/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
+++ b/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
@@ -11,12 +11,7 @@ public class Chapter17Test {
 
     @Test
     public void testJig() {
-        Parser parser = new Parser("""
-int i = 0;
-i=i=1;
-return i;
-                                   //return 3.14;
-""");
+        Parser parser = new Parser("return 1;");
         StopNode stop = parser.parse().iterate();
         assertEquals("return 1;", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop,  0));