#13394: add more tests for the aifc module and use warnings.warn instead of print...

diff --cc Lib/aifc.py
index 775f39c74fb5f554226712607df7fd7c80ba7bdd,775f39c74fb5f554226712607df7fd7c80ba7bdd..ec4f8223aa40ad5becfbbae70d1cc3a047890eb9
--- 1/Lib/aifc.py
--- 2/Lib/aifc.py
+++ b/Lib/aifc.py
@@@ -136,6 -136,6 +136,7 @@@ writeframesraw
  
  import struct
  import builtins
++import warnings
  
  __all__ = ["Error", "open", "openfp"]
  
@@@ -440,7 -440,7 +441,7 @@@ class Aifc_read
              kludge = 0
              if chunk.chunksize == 18:
                  kludge = 1
--                print('Warning: bad COMM chunk size')
++                warnings.warn('Warning: bad COMM chunk size')
                  chunk.chunksize = 23
              #DEBUG end
              self._comptype = chunk.read(4)
@@@ -484,11 -484,11 +485,10 @@@
                      # a position 0 and name ''
                      self._markers.append((id, pos, name))
          except EOFError:
--            print('Warning: MARK chunk contains only', end=' ')
--            print(len(self._markers), end=' ')
--            if len(self._markers) == 1: print('marker', end=' ')
--            else: print('markers', end=' ')
--            print('instead of', nmarkers)
++            w = ('Warning: MARK chunk contains only %s marker%s instead of %s' %
++                 (len(self._markers), '' if len(self._markers) == 1 else 's',
++                  nmarkers))
++            warnings.warn(w)
  
  class Aifc_write:
      # Variables used in this class:

diff --cc Lib/test/test_aifc.py
index 236f9b6610761f0b675562d1fa8fe2b78200020b,ee4ad6b0a32d37b2ec3f83435ef5ba5d47aa2723..ad6f6105ecde2ab65405e804f3441860595d2405
--- 1/Lib/test/test_aifc.py
--- 2/Lib/test/test_aifc.py
+++ b/Lib/test/test_aifc.py
@@@ -1,4 -1,4 +1,4 @@@
- from test.support import findfile, run_unittest, TESTFN
 -from test.support import findfile, run_unittest, TESTFN, captured_stdout, unlink
++from test.support import findfile, run_unittest, TESTFN, unlink
  import unittest
  import os
  import io
@@@ -179,6 -182,148 +182,143 @@@ class AIFCLowLevelTest(unittest.TestCas
          with self.assertRaises(ValueError):
              aifc._write_string(f, b'too long' * 255)
  
 -        with captured_stdout() as s:
+     def test_wrong_open_mode(self):
+         with self.assertRaises(aifc.Error):
+             aifc.open(TESTFN, 'wrong_mode')
+ 
+     def test_read_wrong_form(self):
+         b1 = io.BytesIO(b'WRNG' + struct.pack('>L', 0))
+         b2 = io.BytesIO(b'FORM' + struct.pack('>L', 4) + b'WRNG')
+         self.assertRaises(aifc.Error, aifc.open, b1)
+         self.assertRaises(aifc.Error, aifc.open, b2)
+ 
+     def test_read_no_comm_chunk(self):
+         b = io.BytesIO(b'FORM' + struct.pack('>L', 4) + b'AIFF')
+         self.assertRaises(aifc.Error, aifc.open, b)
+ 
+     def test_read_wrong_compression_type(self):
+         b = b'FORM' + struct.pack('>L', 4) + b'AIFC'
+         b += b'COMM' + struct.pack('>LhlhhLL', 23, 0, 0, 0, 0, 0, 0)
+         b += b'WRNG' + struct.pack('B', 0)
+         self.assertRaises(aifc.Error, aifc.open, io.BytesIO(b))
+ 
+     def test_read_wrong_marks(self):
+         b = b'FORM' + struct.pack('>L', 4) + b'AIFF'
+         b += b'COMM' + struct.pack('>LhlhhLL', 18, 0, 0, 0, 0, 0, 0)
+         b += b'SSND' + struct.pack('>L', 8) + b'\x00' * 8
+         b += b'MARK' + struct.pack('>LhB', 3, 1, 1)
 -        self.assertEqual(
 -            s.getvalue(),
 -            'Warning: MARK chunk contains only 0 markers instead of 1\n')
++        with self.assertWarns(UserWarning):
+             f = aifc.open(io.BytesIO(b))
 -        with captured_stdout() as s:
+         self.assertEqual(f.getmarkers(), None)
+ 
+     def test_read_comm_kludge_compname_even(self):
+         b = b'FORM' + struct.pack('>L', 4) + b'AIFC'
+         b += b'COMM' + struct.pack('>LhlhhLL', 18, 0, 0, 0, 0, 0, 0)
+         b += b'NONE' + struct.pack('B', 4) + b'even' + b'\x00'
+         b += b'SSND' + struct.pack('>L', 8) + b'\x00' * 8
 -        self.assertEqual(s.getvalue(), 'Warning: bad COMM chunk size\n')
++        with self.assertWarns(UserWarning):
+             f = aifc.open(io.BytesIO(b))
 -        with captured_stdout() as s:
+         self.assertEqual(f.getcompname(), b'even')
+ 
+     def test_read_comm_kludge_compname_odd(self):
+         b = b'FORM' + struct.pack('>L', 4) + b'AIFC'
+         b += b'COMM' + struct.pack('>LhlhhLL', 18, 0, 0, 0, 0, 0, 0)
+         b += b'NONE' + struct.pack('B', 3) + b'odd'
+         b += b'SSND' + struct.pack('>L', 8) + b'\x00' * 8
 -        self.assertEqual(s.getvalue(), 'Warning: bad COMM chunk size\n')
++        with self.assertWarns(UserWarning):
+             f = aifc.open(io.BytesIO(b))
+         self.assertEqual(f.getcompname(), b'odd')
+ 
+     def test_write_params_raises(self):
+         fout = aifc.open(io.BytesIO(), 'wb')
+         wrong_params = (0, 0, 0, 0, b'WRNG', '')
+         self.assertRaises(aifc.Error, fout.setparams, wrong_params)
+         self.assertRaises(aifc.Error, fout.getparams)
+         self.assertRaises(aifc.Error, fout.setnchannels, 0)
+         self.assertRaises(aifc.Error, fout.getnchannels)
+         self.assertRaises(aifc.Error, fout.setsampwidth, 0)
+         self.assertRaises(aifc.Error, fout.getsampwidth)
+         self.assertRaises(aifc.Error, fout.setframerate, 0)
+         self.assertRaises(aifc.Error, fout.getframerate)
+         self.assertRaises(aifc.Error, fout.setcomptype, b'WRNG', '')
+         fout.aiff()
+         fout.setnchannels(1)
+         fout.setsampwidth(1)
+         fout.setframerate(1)
+         fout.setnframes(1)
+         fout.writeframes(b'\x00')
+         self.assertRaises(aifc.Error, fout.setparams, (1, 1, 1, 1, 1, 1))
+         self.assertRaises(aifc.Error, fout.setnchannels, 1)
+         self.assertRaises(aifc.Error, fout.setsampwidth, 1)
+         self.assertRaises(aifc.Error, fout.setframerate, 1)
+         self.assertRaises(aifc.Error, fout.setnframes, 1)
+         self.assertRaises(aifc.Error, fout.setcomptype, b'NONE', '')
+         self.assertRaises(aifc.Error, fout.aiff)
+         self.assertRaises(aifc.Error, fout.aifc)
+ 
+     def test_write_params_singles(self):
+         fout = aifc.open(io.BytesIO(), 'wb')
+         fout.aifc()
+         fout.setnchannels(1)
+         fout.setsampwidth(2)
+         fout.setframerate(3)
+         fout.setnframes(4)
+         fout.setcomptype(b'NONE', b'name')
+         self.assertEqual(fout.getnchannels(), 1)
+         self.assertEqual(fout.getsampwidth(), 2)
+         self.assertEqual(fout.getframerate(), 3)
+         self.assertEqual(fout.getnframes(), 0)
+         self.assertEqual(fout.tell(), 0)
+         self.assertEqual(fout.getcomptype(), b'NONE')
+         self.assertEqual(fout.getcompname(), b'name')
+         fout.writeframes(b'\x00' * 4 * fout.getsampwidth() * fout.getnchannels())
+         self.assertEqual(fout.getnframes(), 4)
+         self.assertEqual(fout.tell(), 4)
+ 
+     def test_write_params_bunch(self):
+         fout = aifc.open(io.BytesIO(), 'wb')
+         fout.aifc()
+         p = (1, 2, 3, 4, b'NONE', b'name')
+         fout.setparams(p)
+         self.assertEqual(fout.getparams(), p)
+         fout.initfp(None)
+ 
+     def test_write_header_raises(self):
+         fout = aifc.open(io.BytesIO(), 'wb')
+         self.assertRaises(aifc.Error, fout.close)
+         fout.setnchannels(1)
+         self.assertRaises(aifc.Error, fout.close)
+         fout.setsampwidth(1)
+         self.assertRaises(aifc.Error, fout.close)
+         fout.initfp(None)
+ 
+     def test_write_header_comptype_raises(self):
+         for comptype in (b'ULAW', b'ulaw', b'ALAW', b'alaw', b'G722'):
+             fout = aifc.open(io.BytesIO(), 'wb')
+             fout.setsampwidth(1)
+             fout.setcomptype(comptype, b'')
+             self.assertRaises(aifc.Error, fout.close)
+             fout.initfp(None)
+ 
+     def test_write_markers_raises(self):
+         fout = aifc.open(io.BytesIO(), 'wb')
+         self.assertRaises(aifc.Error, fout.setmark, 0, 0, b'')
+         self.assertRaises(aifc.Error, fout.setmark, 1, -1, b'')
+         self.assertRaises(aifc.Error, fout.setmark, 1, 0, None)
+         self.assertRaises(aifc.Error, fout.getmark, 1)
+         fout.initfp(None)
+ 
+     def test_write_aiff_by_extension(self):
+         sampwidth = 2
+         fout = self.fout = aifc.open(TESTFN + '.aiff', 'wb')
+         fout.setparams((1, sampwidth, 1, 1, b'ULAW', b''))
+         frames = b'\x00' * fout.getnchannels() * sampwidth
+         fout.writeframes(frames)
+         fout.close()
+         f = self.f = aifc.open(TESTFN + '.aiff', 'rb')
+         self.assertEqual(f.getcomptype(), b'NONE')
+         f.close()
+ 
  
  def test_main():
      run_unittest(AIFCTest)

diff --cc Misc/NEWS
index cd522dc6e5ff0eff5467bd6c275d1d6a24d40b0d,5d03fee8e74c83bdb7b1159d548481bd43f81b7b..5cf2e7e55970a1308b86adb2de9b48039f8b502a
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -24,6 -22,6 +24,8 @@@ Core and Builtin
  Library
  -------
  
++- Issue #13394: the aifc module now uses warnings.warn() to signal warnings.
++
  - Issue #14252: Fix subprocess.Popen.terminate() to not raise an error under
    Windows when the child process has already exited.