Merge pull request #80 from astrofrog/test-requirements

Check that pytest-arraydiff is installed

docs/installation.rst

@@ -62,7 +62,19 @@ Install the latest development version from https://github.com/astropy/regions :
     git clone https://github.com/astropy/regions
     cd regions
     python setup.py install
+
+To run the tests, you will need to make sure the `pytest-arraydiff
+<https://pypi.python.org/pypi/pytest-arraydiff>`_ package is installed. Then,
+run the tests with:
+
+.. code-block:: bash
+
     python setup.py test
+
+To build the documentation, do:
+
+.. code-block:: bash
+
     python setup.py build_docs
 
 Optional dependencies

regions/conftest.py

@@ -2,6 +2,17 @@
 # by importing them here in conftest.py they are discoverable by py.test
 # no matter how it is invoked within the source tree.
 
+try:
+    import pytest_arraydiff
+except ImportError:
+    raise ImportError("The pytest-arraydiff package is required for the tests. "
+                      "You can install it with: pip install pytest-arraydiff")
+else:
+    # We need to remove pytest_arraydiff from the namespace otherwise pytest
+    # gets confused, because it tries to interpret pytest_* as a special
+    # function name.
+    del pytest_arraydiff
+
 from astropy.tests.pytest_plugins import *
 
 ## Uncomment the following line to treat all DeprecationWarnings as

setup.py

@@ -114,6 +114,7 @@
           ],
           test=[
               'pytest-mpl',
+              'pytest-arraydiff'
           ],
       ),
       author=AUTHOR,