simple test case for dis module

Lib/test/test_dis.py

+from test.test_support import verify, verbose, TestFailed, run_unittest
+import sys
+import dis
+import StringIO
+
+# Minimal tests for dis module
+
+import unittest
+
+# placement is crucial!!!  move the start of _f and you have to adjust the
+# line numbers in dis_f
+def _f(a):
+  print a
+  return 1
+
+dis_f = """\
+ 13           0 LOAD_FAST                0 (a)
+              3 PRINT_ITEM          
+              4 PRINT_NEWLINE       
+
+ 14           5 LOAD_CONST               1 (1)
+              8 RETURN_VALUE        
+              9 LOAD_CONST               0 (None)
+             12 RETURN_VALUE        
+"""
+
+class DisTests(unittest.TestCase):
+    def test_opmap(self):
+        self.assertEqual(dis.opmap["STOP_CODE"], 0)
+        self.assertEqual(dis.opmap["LOAD_CONST"] in dis.hasconst, True)
+        self.assertEqual(dis.opmap["STORE_NAME"] in dis.hasname, True)
+
+    def test_opname(self):
+        self.assertEqual(dis.opname[dis.opmap["LOAD_FAST"]], "LOAD_FAST")
+
+    def test_boundaries(self):
+        self.assertEqual(dis.opmap["EXTENDED_ARG"], dis.EXTENDED_ARG)
+        self.assertEqual(dis.opmap["STORE_NAME"], dis.HAVE_ARGUMENT)
+
+    def test_dis(self):
+        s = StringIO.StringIO()
+        save_stdout = sys.stdout
+        sys.stdout = s
+        dis.dis(_f)
+        sys.stdout = save_stdout
+        self.assertEqual(dis_f, s.getvalue())
+
+def test_main():
+    run_unittest(DisTests)
+
+
+if __name__ == "__main__":
+    test_main()