Merge pull request #109 from mrbean-bremen/fake_io_open

Fake io open

Author: jmcgeheeiv

fake_filesystem_unittest_test.py

@@ -18,7 +18,7 @@
 """
 Test the :py:class`pyfakefs.fake_filesystem_unittest.TestCase` base class.
 """
-
+import io
 import os
 import glob
 import shutil
@@ -65,6 +65,17 @@ def test_open(self):
         self.assertEqual(content,
                          'This test file was created using the open() function.\n')
 
+    def test_io_open(self):
+        '''Fake io module is bound'''
+        self.assertFalse(os.path.exists('/fake_file.txt'))
+        with io.open('/fake_file.txt', 'w') as f:
+            f.write("This test file was created using the io.open() function.\n")
+        self.assertTrue(self.fs.Exists('/fake_file.txt'))
+        with open('/fake_file.txt') as f:
+            content = f.read()
+        self.assertEqual(content,
+                         'This test file was created using the io.open() function.\n')
+
     def test_os(self):
         '''Fake os module is bound'''
         self.assertFalse(self.fs.Exists('/test/dir1/dir2'))

pyfakefs/fake_filesystem.py

@@ -2418,6 +2418,33 @@ def __getattr__(self, name):
     """Forwards any unfaked calls to the standard os module."""
     return getattr(self._os_module, name)
 
+class FakeIoModule(object):
+  """Uses FakeFilesystem to provide a fake io module replacement.
+     Currently only used to wrap io.open() which is an alias to open()
+
+  # You need a fake_filesystem to use this:
+  filesystem = fake_filesystem.FakeFilesystem()
+  my_io_module = fake_filesystem.FakeIoModule(filesystem)
+  """
+
+  def __init__(self, filesystem):
+    """
+    Args:
+      filesystem:  FakeFilesystem used to provide file system information
+    """
+    self.filesystem = filesystem
+
+  def open(self, file_path, mode='r', buffering=-1, encoding=None,
+           errors=None, newline=None, closefd=True, opener=None):
+    """Redirect the call to FakeFileOpen.
+    See FakeFileOpen.Call() for description.
+    """
+    if opener is not None and sys.version_info < (3, 3):
+      raise TypeError("open() got an unexpected keyword argument 'opener'")
+    return FakeFileOpen(self.filesystem).Call(
+      file_path, mode, buffering, encoding, errors, newline, closefd, opener)
+
+
 class FakeFileWrapper(object):
   """Wrapper for a StringIO object for use by a FakeFile object.
 

pyfakefs/fake_filesystem_unittest.py

@@ -115,7 +115,7 @@ class Patcher(object):
 
     # To add py.test support per issue https://github.com/jmcgeheeiv/pyfakefs/issues/43,
     # it appears that adding  'py', 'pytest', '_pytest' to SKIPNAMES will help
-    SKIPNAMES = set(['os', 'glob', 'path', 'shutil', 'tempfile'])
+    SKIPNAMES = set(['os', 'glob', 'path', 'shutil', 'tempfile', 'io'])
 
     def __init__(self):
         # Attributes set by _findModules()
@@ -124,6 +124,7 @@ def __init__(self):
         self._pathModules = None
         self._shutilModules = None
         self._tempfileModules = None
+        self._ioModules = None
         self._findModules()
         assert None not in vars(self).values(), \
                 "_findModules() missed the initialization of an instance variable"
@@ -137,6 +138,7 @@ def __init__(self):
         self.fake_shutil = None
         self.fake_tempfile_ = None
         self.fake_open = None
+        self.fake_io = None
         # _isStale is set by tearDown(), reset by _refresh()
         self._isStale = True
         self._refresh()
@@ -154,6 +156,7 @@ def _findModules(self):
         self._pathModules = set()
         self._shutilModules = set()
         self._tempfileModules = set()
+        self._ioModules = set()
         for name, module in set(sys.modules.items()):
             if (module in self.SKIPMODULES or
                 (not inspect.ismodule(module)) or
@@ -169,6 +172,8 @@ def _findModules(self):
                 self._shutilModules.add(module)
             if 'tempfile' in module.__dict__:
                 self._tempfileModules.add(module)
+            if 'io' in module.__dict__:
+                self._ioModules.add(module)
 
     def _refresh(self):
         '''Renew the fake file system and set the _isStale flag to `False`.'''
@@ -183,6 +188,7 @@ def _refresh(self):
         self.fake_shutil = fake_filesystem_shutil.FakeShutilModule(self.fs)
         self.fake_tempfile_ = fake_tempfile.FakeTempfileModule(self.fs)
         self.fake_open = fake_filesystem.FakeFileOpen(self.fs)
+        self.fake_io = fake_filesystem.FakeIoModule(self.fs)
 
         self._isStale = False
 
@@ -211,6 +217,8 @@ def setUp(self, doctester=None):
             self._stubs.SmartSet(module,  'shutil', self.fake_shutil)
         for module in self._tempfileModules:
             self._stubs.SmartSet(module,  'tempfile', self.fake_tempfile_)
+        for module in self._ioModules:
+            self._stubs.SmartSet(module,  'io', self.fake_io)
 
     def replaceGlobs(self, globs_):
         globs = globs_.copy()
@@ -228,6 +236,8 @@ def replaceGlobs(self, globs_):
             globs['shutil'] = fake_filesystem_shutil.FakeShutilModule(self.fs)
         if 'tempfile' in globs:
             globs['tempfile'] = fake_tempfile.FakeTempfileModule(self.fs)
+        if 'io' in globs:
+            globs['io'] = fake_filesystem.FakeIoModule(self.fs)
         return globs
 
     def tearDown(self, doctester=None):