Handle tempfile content encoding

When a tempfile tuple is given to create allow that tuple
to optionally provide the encoding to use when the content
string is written (default it to utf-8 if not provided).

This is to resolve the need to worry about encodings when
oslotest is used in py3.x where the tempfiles that are currently
opened are opened in binary mode (and therefore aren't able
to write unicode strings without encoding).

Change-Id: Ibd42d14977b3438aada162199d82661c58fa5f73

oslotest/base.py

@@ -20,6 +20,7 @@ import os
 import tempfile
 
 import fixtures
+import six
 from six.moves import mock
 import testtools
 
@@ -121,17 +122,29 @@ class BaseTestCase(testtools.TestCase):
         else:
             logging.basicConfig(format=_LOG_FORMAT, level=level)
 
-    def create_tempfiles(self, files, ext='.conf'):
+    def create_tempfiles(self, files, ext='.conf', default_encoding='utf-8'):
         """Safely create temporary files.
 
         :param files: Sequence of tuples containing (filename, file_contents).
         :type files: list of tuple
         :param ext: File name extension for the temporary file.
         :type ext: str
+        :param default_encoding: Default file content encoding when it is
+                                 not provided, used to decode the tempfile
+                                 contents from a text string into a binary
+                                 string.
+        :type default_encoding: str
         :return: A list of str with the names of the files created.
         """
         tempfiles = []
-        for (basename, contents) in files:
+        for f in files:
+            if len(f) == 3:
+                basename, contents, encoding = f
+            else:
+                basename, contents = f
+                encoding = default_encoding
+            if isinstance(contents, six.text_type):
+                contents = contents.encode(encoding)
             if not os.path.isabs(basename):
                 (fd, path) = tempfile.mkstemp(prefix=basename, suffix=ext)
             else:

tests/unit/test_base.py

@@ -1,3 +1,5 @@
+# -*- coding: utf-8 -*-
+
 # Copyright 2014 Deutsche Telekom AG
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -13,8 +15,10 @@
 #    under the License.
 
 import logging
+import os
 import unittest
 
+import six
 from six.moves import mock
 import testtools
 
@@ -121,3 +125,52 @@ class TestManualMock(base.BaseTestCase):
         patcher = mock.patch('os.environ.get')
         patcher.start()
         self.addCleanup(patcher.stop)
+
+
+class TestTempFiles(base.BaseTestCase):
+    def test_create_unicode_files(self):
+        files = [["no_approve", u'ಠ_ಠ']]
+        temps = self.create_tempfiles(files)
+        self.assertEqual(1, len(temps))
+        with open(temps[0], 'rb') as f:
+            contents = f.read()
+        self.assertEqual(u'ಠ_ಠ', six.text_type(contents, encoding='utf-8'))
+
+    def test_create_unicode_files_encoding(self):
+        files = [["embarrassed", u'⊙﹏⊙', 'utf-8']]
+        temps = self.create_tempfiles(files)
+        self.assertEqual(1, len(temps))
+        with open(temps[0], 'rb') as f:
+            contents = f.read()
+        self.assertEqual(u'⊙﹏⊙', six.text_type(contents, encoding='utf-8'))
+
+    def test_create_unicode_files_multi_encoding(self):
+        files = [
+            ["embarrassed", u'⊙﹏⊙', 'utf-8'],
+            ['abc', 'abc', 'ascii'],
+        ]
+        temps = self.create_tempfiles(files)
+        self.assertEqual(2, len(temps))
+        for i, (basename, raw_contents, raw_encoding) in enumerate(files):
+            with open(temps[i], 'rb') as f:
+                contents = f.read()
+            if not isinstance(raw_contents, six.text_type):
+                raw_contents = six.text_type(raw_contents,
+                                             encoding=raw_encoding)
+            self.assertEqual(raw_contents,
+                             six.text_type(contents, encoding=raw_encoding))
+
+    def test_create_bad_encoding(self):
+        files = [["hrm", u'ಠ~ಠ', 'ascii']]
+        self.assertRaises(UnicodeError, self.create_tempfiles, files)
+
+    def test_prefix(self):
+        files = [["testing", '']]
+        temps = self.create_tempfiles(files)
+        self.assertEqual(1, len(temps))
+        basename = os.path.basename(temps[0])
+        self.assertTrue(basename.startswith('testing'))
+
+    def test_wrong_length(self):
+        files = [["testing"]]
+        self.assertRaises(ValueError, self.create_tempfiles, files)