1  # encoding: utf-8
   2  """Tests for io.py"""
   3  
   4  # Copyright (c) IPython Development Team.
   5  # Distributed under the terms of the Modified BSD License.
   6  
   7  
   8  import sys
   9  from io import StringIO
  10  
  11  import unittest
  12  
  13  from IPython.utils.io import Tee, capture_output
  14  
  15  
  16  def test_tee_simple():
  17      "Very simple check with stdout only"
  18      chan = StringIO()
  19      text = 'Hello'
  20      tee = Tee(chan, channel='stdout')
  21      print(text, file=chan)
  22      assert chan.getvalue() == text + "\n"
  23      tee.close()
  24  
  25  
  26  class TeeTestCase(unittest.TestCase):
  27  
  28      def tchan(self, channel):
  29          trap = StringIO()
  30          chan = StringIO()
  31          text = 'Hello'
  32          
  33          std_ori = getattr(sys, channel)
  34          setattr(sys, channel, trap)
  35  
  36          tee = Tee(chan, channel=channel)
  37  
  38          print(text, end='', file=chan)
  39          trap_val = trap.getvalue()
  40          self.assertEqual(chan.getvalue(), text)
  41  
  42          tee.close()
  43  
  44          setattr(sys, channel, std_ori)
  45          assert getattr(sys, channel) == std_ori
  46  
  47      def test(self):
  48          for chan in ['stdout', 'stderr']:
  49              self.tchan(chan)
  50  
  51  class TestIOStream(unittest.TestCase):
  52  
  53      def test_capture_output(self):
  54          """capture_output() context works"""
  55          
  56          with capture_output() as io:
  57              print("hi, stdout")
  58              print("hi, stderr", file=sys.stderr)
  59  
  60          self.assertEqual(io.stdout, "hi, stdout\n")
  61          self.assertEqual(io.stderr, "hi, stderr\n")
  62