Add tests for core.util (#138)

* Add tests for core.util

Mock now a requirement

.travis.yml

@@ -16,6 +16,7 @@ branches:
 # install python dependencies
 install:
   - pip install codecov
+  - pip install mock
   - pip install pytest-cov
   - pip install pytest-pep8
   - pip install numpy

conda/datreant.core/meta.yaml

@@ -32,6 +32,7 @@ requirements:
     - python-levenshtein
     - datreant
     - pytest
+    - mock
 
 test:
   imports:

setup.py

@@ -31,6 +31,6 @@
       scripts=[],
       license='BSD',
       long_description=open('README.rst').read(),
-      tests_require = ['numpy', 'pytest'],
+      tests_require = ['numpy', 'pytest', 'mock'],
       install_requires=['asciitree', 'pathlib2', 'scandir', 'six', 'fuzzywuzzy']
       )

src/datreant/core/tests/test_util.py

@@ -0,0 +1,33 @@
+import mock
+import os
+import pytest
+
+import datreant.core as dtr
+
+
+class TestMakedirs(object):
+    def test_makedirs(self, tmpdir):
+        with tmpdir.as_cwd():
+            dtr.util.makedirs('this/should/exist')
+            assert os.path.exists('this/should/exist')
+            assert os.path.isdir('this/should/exist')
+
+    def test_makedirs_exists(self, tmpdir):
+        # try and make a dir twice
+        with tmpdir.as_cwd():
+            os.mkdir('this/')
+            dtr.util.makedirs('this/')
+            assert os.path.exists('this/')
+            assert os.path.isdir('this/')
+
+    def test_makedirs_error_catch(self, tmpdir):
+        # mock a disk full error
+        # and make sure it gets propagated through properly
+        with tmpdir.as_cwd():
+            with mock.patch('os.makedirs') as mp:
+                mp.side_effect = OSError(os.errno.ENOSPC, 'Mock - disk full')
+                # check the specific error code
+                # ie check we don't mangle it enroute
+                with pytest.raises(OSError) as error:
+                    dtr.util.makedirs('this/should/fail')
+                    assert error.errno == os.errno.ENOSPC