Make compiler.{get|require}_executable public

Some internal functions in thrift.compiler are reusable in unit tests.
Explicitly expose them and use them.

sparts/thrift/compiler.py

@@ -32,21 +32,24 @@ def compile(path, root='.', debug=False, **kwargs):
     return comp.importThrift(path, **kwargs)
 
 
-def _require_executable(name, fallback):
-    """Given `name`, assert on and return the path to that binary."""
-    path = distutils.spawn.find_executable(name)
+def get_executable():
+    """Returns the thrift compiler path if found in the PATH, else None"""
+    path = distutils.spawn.find_executable('thrift1')
     if path is None:
-        path = distutils.spawn.find_executable(fallback)
+        path = distutils.spawn.find_executable('thrift')
+    return path
 
-    assert path is not None, \
-        'Unable to find %s or %s in PATH' % (name, fallback)
+def require_executable():
+    """Assert that the thrift compiler is in the PATH.  Returns the path"""
+    path = get_executable()
+    assert path is not None, 'Unable to find thrift compiler in PATH'
     return path
 
 
 class CompileContext(object):
     def __init__(self, root='.', debug=False):
         self.root = root
-        self.thrift_bin = _require_executable('thrift1', 'thrift')
+        self.thrift_bin = require_executable()
         self.include_dirs = OrderedDict()
         self.dep_files = {}
         self.dep_contents = {}

tests/tasks/thrift/test_multiplexed.py

@@ -18,9 +18,7 @@
     raise Skip("Need thrift language bindings to run this test")
 
 # Make sure we have the thrift compiler
-try:
-    compiler._require_executable('thrift1', 'thrift')
-except AssertionError:
+if compiler.get_executable() is None:
     raise Skip("Need thrift compiler to run this test")
 
 # String containing .thrift file contents for some example services

tests/thrift/test_compiler.py

@@ -7,14 +7,9 @@
 from sparts.tests.base import BaseSpartsTestCase, Skip
 from sparts.thrift import compiler
 
-import distutils.spawn
-import sys
-
 # Only run thrift compiler test if the thrift compiler was found.
-if distutils.spawn.find_executable('thrift') is None:
+if compiler.get_executable() is None:
     raise Skip("Unable to find thrift binary on this system")
-if sys.version >= '3':
-    raise Skip("Thrift compiler is currently incompatible with py3k")
 
 
 class ContextTests(BaseSpartsTestCase):