Skip tests on unsupported platforms (#475)

* Add function to check if running system is supported
* skip tests that except running on supported platforms

okonomiyaki/runtimes/tests/test_runtime.py

@@ -1,9 +1,10 @@
-import os.path
 import sys
+import os.path
 import unittest
 
 from okonomiyaki.platforms import EPDPlatform
 from okonomiyaki.versions import RuntimeVersion
+from okonomiyaki.utils.testing import known_system
 
 from ..runtime import PythonRuntime
 
@@ -13,6 +14,10 @@
 
 
 class TestPythonRuntime(unittest.TestCase):
+
+    @unittest.skipIf(
+        not known_system,
+        'This test should be executed only on Enthought supported platforms')
     def test_simple_from_running_python(self):
         # When
         runtime_info = PythonRuntime.from_running_python()

okonomiyaki/utils/testing.py

@@ -1,3 +1,6 @@
+from okonomiyaki.errors import OkonomiyakiError
+
+
 class Patcher(object):
     """ A dumb class to allow a mock.patch object to be used as a decorator and
     a context manager
@@ -48,3 +51,16 @@ def __enter__(self):
     def __exit__(self, *a, **kw):
         for patcher in self._patchers:
             patcher.__exit__(*a, **kw)
+
+
+def known_system(self):
+    from okonomiyaki.plarforms._platform import (
+        _guess_os_kind, _guess_platform, _guess_platform_details)
+    try:
+        os_kind = _guess_os_kind()
+        _guess_platform(os_kind)
+        _guess_platform_details(os_kind)
+    except OkonomiyakiError:
+        return False
+    else:
+        return True