1 files changed, 36 insertions, 0 deletions
diff --git a/prolog/problems/denotational_semantics/prog_listswap_3/common.py b/prolog/problems/denotational_semantics/prog_listswap_3/common.py
index 800717e..f8238c6 100644
--- a/prolog/problems/denotational_semantics/prog_listswap_3/common.py
+++ b/prolog/problems/denotational_semantics/prog_listswap_3/common.py
@@ -1,3 +1,10 @@
+from operator import itemgetter
+import socket
+
+import prolog.engine
+import prolog.util
+from server.hints import Hint, HintPopup
+
 id = 174
 number = 20
 visible = True
@@ -48,3 +55,32 @@ instr((R0,C0)-->(R,C0)) -->
     [swap],
     { swap(R0, C0, R) }.
 '''
+
+test_cases = [
+    ('findall(W, (W = [_], prog_listswap(_, W, [])), Words), Words == []',
+        [{}]),
+    ('prog_listswap([1,2,3,4]-->Out, [begin,right,right,swap,end], []), Out == [1,3,2,4]',
+        [{}]),
+    ('prog_listswap([a,b,c,d,e]-->Out, [begin,right,right,swap,left,swap,end], []), Out == [c,a,b,d,e]',
+        [{}]),
+]
+
+def test(code, aux_code):
+    n_correct = 0
+    engine_id = None
+    try:
+        engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)
+        if engine_id is not None and 'error' not in map(itemgetter(0), output):
+            # Engine successfully created, and no syntax error in program.
+            for query, answers in test_cases:
+                if prolog.engine.check_answers(engine_id, query=query, answers=answers, timeout=1.0):
+                    n_correct += 1
+    except socket.timeout:
+        pass
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
+    hints = [{'id': 'test_results', 'args': {'passed': n_correct, 'total': len(test_cases)}}]
+    return n_correct, len(test_cases), hints
+