Refactored how entry points work.

tests/util_test.py

@@ -0,0 +1,28 @@
+
+import mock
+import pytest
+import sys
+
+from pre_commit.util import entry
+
+
+@pytest.fixture
+def entry_func():
+    @entry
+    def func(argv):
+        return argv
+
+    return func
+
+
+def test_explicitly_passed_argv_are_passed(entry_func):
+    input = object()
+    ret = entry_func(input)
+    assert ret is input
+
+
+def test_no_arguments_passed_uses_argv(entry_func):
+    argv = [1, 2, 3, 4]
+    with mock.patch.object(sys, 'argv', argv):
+        ret = entry_func()
+        assert ret == argv[1:]