diff --git a/tests/samples/if.yml b/tests/samples/if.yml
index 9604e67..bdde5f5 100644
--- a/tests/samples/if.yml
+++ b/tests/samples/if.yml
@@ -8,15 +8,10 @@ b: 2
 !if false:
   e: 5
   f: 6
-!if true:  
-  g: 
-    - ? !if true
-      : - 7
+
 ---
 # output
 a: 1
 b: 2
 c: 3
 d: 4
-g: 
-  - 7
\ No newline at end of file
diff --git a/tests/samples/overlay.yml b/tests/samples/overlay.yml
deleted file mode 100644
index 0ff4f58..0000000
--- a/tests/samples/overlay.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-#input
-left: !-
-  a:
-    b: !? 2
-  c: 1
-
-right: !-
-  a:
-    b: !? 3
-  d: 4
-
-# Recursive mapping merge with customization implemented in YAQL.
-# Will probably be available in some way as a function in future versions of Yglu.
-merge: !() 
-  let(arg => $) ->
-  switch(
-    $.l = $.L.a => $.r + $.l + { b => $.r.b + $.l.b },
-    isDict($.r) => dict($.l.items() + $.r.items() + 
-      set($.r.keys()).intersect(set($.l.keys()))
-        .select([$, ($_.merge)({l => $arg.l[$], r => $arg.r[$], L => $arg.L, R => $arg.R})]) 
-    ),
-    true => $.l  
-  )
-
-merged: !? ($_.merge)({l => $_.left, r => $_.right, L => $_.left, R => $_.right, p => ''})
-
----
-# output
-merged:
-  a:
-    b: 5
-  c: 1
-  d: 4
\ No newline at end of file
diff --git a/tests/test_samples.py b/tests/test_samples.py
index c3a5f11..d040627 100644
--- a/tests/test_samples.py
+++ b/tests/test_samples.py
@@ -22,5 +22,12 @@ def simple_name(filename):
 @pytest.mark.parametrize("filename", files)
 def test_sample(filename):
     with open(filename) as file_handle:
-        (input, output) = process_all(file_handle, filename)
+        (input, output) = process_all(file_handle, filename, FailingErrorHandler())
         assert_like(input, output)
+
+class FailingErrorHandler(list):
+    def __init__(self):
+        self.nodes = set()
+
+    def append(self, error):
+        raise error