Fix known_sytem function and check in tests (#485)

* Fix known_sytem function and check in tests
- Pass the correct object to _guess_platform
- Add Arch into the platforms namespace

okonomiyaki/platforms/__init__.py

@@ -2,12 +2,12 @@
 from .abi import PlatformABI, default_abi
 from .epd_platform import EPDPlatform, applies
 from ._platform import Platform, OSKind, FamilyKind, NameKind
-from ._arch import X86, X86_64, ARM64
+from ._arch import X86, X86_64, ARM64, Arch
 from .pep425 import compute_abi_tag, compute_python_tag, compute_platform_tag
 from .python_implementation import PythonABI, PythonImplementation
 
 
 __all__ = [
     'X86', 'X86_64', 'ARM64', 'EPDPlatform', 'Platform', 'PythonImplementation',
-    'default_abi'
+    'default_abi','Arch'
 ]

okonomiyaki/runtimes/tests/test_runtime.py

@@ -16,7 +16,7 @@
 class TestPythonRuntime(unittest.TestCase):
 
     @unittest.skipIf(
-        not known_system,
+        not known_system(),
         'This test should be executed only on Enthought supported platforms')
     def test_simple_from_running_python(self):
         # When

okonomiyaki/utils/testing.py

@@ -53,12 +53,13 @@ def __exit__(self, *a, **kw):
             patcher.__exit__(*a, **kw)
 
 
-def known_system(self):
-    from okonomiyaki.plarforms._platform import (
-        _guess_os_kind, _guess_platform, _guess_platform_details)
+def known_system():
+    from okonomiyaki.platforms import Arch
+    from okonomiyaki.platforms._platform import (
+        _guess_os_kind, _guess_platform_details)
     try:
+        Arch.from_running_system()
         os_kind = _guess_os_kind()
-        _guess_platform(os_kind)
         _guess_platform_details(os_kind)
     except OkonomiyakiError:
         return False