Bug 937803 - os.path.exists should work with MockedOpen; r=glandium

--HG--
extra : rebase_source : 567b70b6a75f3c918da2c99ceb490ac569919ed0

config/mozunit.py

@@ -129,11 +129,24 @@ class MockedOpen(object):
     def __enter__(self):
         import __builtin__
         self.open = __builtin__.open
+        self._orig_path_exists = os.path.exists
         __builtin__.open = self
+        os.path.exists = self._wrapped_exists
 
     def __exit__(self, type, value, traceback):
         import __builtin__
         __builtin__.open = self.open
+        os.path.exists = self._orig_path_exists
+
+    def _wrapped_exists(self, p):
+        if p in self.files:
+            return True
+
+        abspath = os.path.abspath(p)
+        if abspath in self.files:
+            return True
+
+        return self._orig_path_exists(p)
 
 def main(*args):
     unittest.main(testRunner=MozTestRunner(),*args)

config/tests/unit-mozunit.py

@@ -15,8 +15,15 @@ class TestMozUnit(unittest.TestCase):
         with os.fdopen(fd, 'w') as file:
             file.write('foobar');
 
+        self.assertFalse(os.path.exists('file1'))
+        self.assertFalse(os.path.exists('file2'))
+
         with MockedOpen({'file1': 'content1',
                          'file2': 'content2'}):
+            self.assertTrue(os.path.exists('file1'))
+            self.assertTrue(os.path.exists('file2'))
+            self.assertFalse(os.path.exists('foo/file1'))
+
             # Check the contents of the files given at MockedOpen creation.
             self.assertEqual(open('file1', 'r').read(), 'content1')
             self.assertEqual(open('file2', 'r').read(), 'content2')
@@ -24,6 +31,7 @@ class TestMozUnit(unittest.TestCase):
             # Check that overwriting these files alters their content.
             with open('file1', 'w') as file:
                 file.write('foo')
+            self.assertTrue(os.path.exists('file1'))
             self.assertEqual(open('file1', 'r').read(), 'foo')
 
             # ... but not until the file is closed.
@@ -38,13 +46,17 @@ class TestMozUnit(unittest.TestCase):
                 file.write('bar')
             self.assertEqual(open('file1', 'r').read(), 'foobar')
 
+            self.assertFalse(os.path.exists('file3'))
+
             # Opening a non-existing file ought to fail.
             self.assertRaises(IOError, open, 'file3', 'r')
+            self.assertFalse(os.path.exists('file3'))
 
             # Check that writing a new file does create the file.
             with open('file3', 'w') as file:
                 file.write('baz')
             self.assertEqual(open('file3', 'r').read(), 'baz')
+            self.assertTrue(os.path.exists('file3'))
 
             # Check the content of the file created outside MockedOpen.
             self.assertEqual(open(path, 'r').read(), 'foobar')