A better way to neuter decorators when not testing.

2 files changed, 22 insertions, 12 deletions

diff --git a/coverage/misc.py b/coverage/misc.py
index e78a1537..797a16d5 100644
--- a/coverage/misc.py
+++ b/coverage/misc.py
@@ -39,6 +39,13 @@ def isolate_module(mod):
 os = isolate_module(os)
 
 
+def dummy_decorator_with_args(*args_unused, **kwargs_unused):
+    """Dummy no-op implementation of a decorator with arguments."""
+    def _decorator(func):
+        return func
+    return _decorator
+
+
 # Use PyContracts for assertion testing on parameters and returns, but only if
 # we are running our own test suite.
 if env.TESTING:
@@ -70,22 +77,15 @@ if env.TESTING:
             return _wrapped
         return _decorator
 else:                                           # pragma: not covered
-    # We aren't using real PyContracts, so just define a no-op decorator as a
-    # stunt double.
-    def contract(**unused):
-        """Dummy no-op implementation of `contract`."""
-        return lambda func: func
+    # We aren't using real PyContracts, so just define our decorators as
+    # stunt-double no-ops.
+    contract = dummy_decorator_with_args
+    one_of = dummy_decorator_with_args
 
     def new_contract(*args_unused, **kwargs_unused):
         """Dummy no-op implementation of `new_contract`."""
         pass
 
-    def one_of(argnames_unused):
-        """Dummy no-op implementation of `one_of`."""
-        def _decorator(func):
-            return func
-        return _decorator
-
 
 def nice_pair(pair):
     """Make a nice string representation of a pair of numbers.
diff --git a/tests/test_misc.py b/tests/test_misc.py
index 0b6c9144..fc95744a 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -9,7 +9,7 @@ import pytest
 
 import coverage
 from coverage.version import _make_url, _make_version
-from coverage.misc import contract, file_be_gone, Hasher, one_of
+from coverage.misc import contract, dummy_decorator_with_args, file_be_gone, Hasher, one_of
 
 from tests.coveragetest import CoverageTest
 
@@ -109,6 +109,16 @@ class ContractTest(CoverageTest):
         with pytest.raises(AssertionError):
             give_me_one()
 
+    def test_dummy_decorator_with_args(self):
+        @dummy_decorator_with_args("anything", this=17, that="is fine")
+        def undecorated(a=None, b=None):                # pylint: disable=missing-docstring
+            return (a, b)
+
+        assert undecorated() == (None, None)
+        assert undecorated(17) == (17, None)
+        assert undecorated(b=23) == (None, 23)
+        assert undecorated(b=42, a=3) == (3, 42)
+
 
 class VersionTest(CoverageTest):
     """Tests of version.py"""