Merge pull request #4581 from takluyver/i4578

Writing unicode to stdout

IPython/utils/tests/test_io.py

@@ -12,7 +12,9 @@
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
+from __future__ import absolute_import
 
+import io as stdlib_io
 import sys
 
 from subprocess import Popen, PIPE
@@ -20,7 +22,8 @@ import unittest
 
 import nose.tools as nt
 
-from IPython.utils.io import Tee, capture_output
+from IPython.testing.decorators import skipif
+from IPython.utils.io import Tee, capture_output, unicode_std_stream
 from IPython.utils.py3compat import doctest_refactor_print, PY3
 
 if PY3:
@@ -88,3 +91,34 @@ def test_capture_output():
     
     nt.assert_equal(io.stdout, 'hi, stdout\n')
     nt.assert_equal(io.stderr, 'hi, stderr\n')
+
+def test_UnicodeStdStream():
+    # Test wrapping a bytes-level stdout
+    if PY3:
+        stdoutb = stdlib_io.BytesIO()
+        stdout = stdlib_io.TextIOWrapper(stdoutb, encoding='ascii')
+    else:
+        stdout = stdoutb = stdlib_io.BytesIO()
+
+    orig_stdout = sys.stdout
+    sys.stdout = stdout
+    try:
+        sample = u"@łe¶ŧ←"
+        unicode_std_stream().write(sample)
+
+        output = stdoutb.getvalue().decode('utf-8')
+        nt.assert_equal(output, sample)
+        assert not stdout.closed
+    finally:
+        sys.stdout = orig_stdout
+
+@skipif(not PY3, "Not applicable on Python 2")
+def test_UnicodeStdStream_nowrap():
+    # If we replace stdout with a StringIO, it shouldn't get wrapped.
+    orig_stdout = sys.stdout
+    sys.stdout = StringIO()
+    try:
+        nt.assert_is(unicode_std_stream(), sys.stdout)
+        assert not sys.stdout.closed
+    finally:
+        sys.stdout = orig_stdout