1 files changed, 36 insertions, 0 deletions
diff --git a/Lib/lib2to3/tests/test_main.py b/Lib/lib2to3/tests/test_main.py
new file mode 100644
index 0000000..23d1b56
--- /dev/null
+++ b/Lib/lib2to3/tests/test_main.py
@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+import sys
+import codecs
+import io
+import unittest
+
+from lib2to3 import main
+
+
+class TestMain(unittest.TestCase):
+
+    def run_2to3_capture(self, args, in_capture, out_capture, err_capture):
+        save_stdin = sys.stdin
+        save_stdout = sys.stdout
+        save_stderr = sys.stderr
+        sys.stdin = in_capture
+        sys.stdout = out_capture
+        sys.stderr = err_capture
+        try:
+            return main.main("lib2to3.fixes", args)
+        finally:
+            sys.stdin = save_stdin
+            sys.stdout = save_stdout
+            sys.stderr = save_stderr
+
+    def test_unencodable_diff(self):
+        input_stream = io.StringIO("print 'nothing'\nprint u'über'\n")
+        out = io.StringIO()
+        out_enc = codecs.getwriter("ascii")(out)
+        err = io.StringIO()
+        ret = self.run_2to3_capture(["-"], input_stream, out_enc, err)
+        self.assertEqual(ret, 0)
+        output = out.getvalue()
+        self.assertTrue("-print 'nothing'" in output)
+        self.assertTrue("WARNING: couldn't encode <stdin>'s diff for "
+                        "your terminal" in err.getvalue())