config/tests/unit-mozunit.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 import os
   6 import unittest
   7 from tempfile import mkstemp
   8
   9 from mozunit import MockedOpen, main
  10
  11
  12 class TestMozUnit(unittest.TestCase):
  13     def test_mocked_open(self):
  14         # Create a temporary file on the file system.
  15         (fd, path) = mkstemp()
  16         with os.fdopen(fd, "w") as file:
  17             file.write("foobar")
  18
  19         self.assertFalse(os.path.exists("file1"))
  20         self.assertFalse(os.path.exists("file2"))
  21
  22         with MockedOpen({"file1": "content1", "file2": "content2"}):
  23             self.assertTrue(os.path.exists("file1"))
  24             self.assertTrue(os.path.exists("file2"))
  25             self.assertFalse(os.path.exists("foo/file1"))
  26
  27             # Check the contents of the files given at MockedOpen creation.
  28             self.assertEqual(open("file1", "r").read(), "content1")
  29             self.assertEqual(open("file2", "r").read(), "content2")
  30
  31             # Check that overwriting these files alters their content.
  32             with open("file1", "w") as file:
  33                 file.write("foo")
  34             self.assertTrue(os.path.exists("file1"))
  35             self.assertEqual(open("file1", "r").read(), "foo")
  36
  37             # ... but not until the file is closed.
  38             file = open("file2", "w")
  39             file.write("bar")
  40             self.assertEqual(open("file2", "r").read(), "content2")
  41             file.close()
  42             self.assertEqual(open("file2", "r").read(), "bar")
  43
  44             # Check that appending to a file does append
  45             with open("file1", "a") as file:
  46                 file.write("bar")
  47             self.assertEqual(open("file1", "r").read(), "foobar")
  48
  49             self.assertFalse(os.path.exists("file3"))
  50
  51             # Opening a non-existing file ought to fail.
  52             self.assertRaises(IOError, open, "file3", "r")
  53             self.assertFalse(os.path.exists("file3"))
  54
  55             # Check that writing a new file does create the file.
  56             with open("file3", "w") as file:
  57                 file.write("baz")
  58             self.assertEqual(open("file3", "r").read(), "baz")
  59             self.assertTrue(os.path.exists("file3"))
  60
  61             # Check the content of the file created outside MockedOpen.
  62             self.assertEqual(open(path, "r").read(), "foobar")
  63
  64             # Check that overwriting a file existing on the file system
  65             # does modify its content.
  66             with open(path, "w") as file:
  67                 file.write("bazqux")
  68             self.assertEqual(open(path, "r").read(), "bazqux")
  69
  70         with MockedOpen():
  71             # Check that appending to a file existing on the file system
  72             # does modify its content.
  73             with open(path, "a") as file:
  74                 file.write("bazqux")
  75             self.assertEqual(open(path, "r").read(), "foobarbazqux")
  76
  77         # Check that the file was not actually modified on the file system.
  78         self.assertEqual(open(path, "r").read(), "foobar")
  79         os.remove(path)
  80
  81         # Check that the file created inside MockedOpen wasn't actually
  82         # created.
  83         self.assertRaises(IOError, open, "file3", "r")
  84
  85
  86 if __name__ == "__main__":
  87     main()