Move DD code into its own directory (#6)

reference/tests/contrib/test_utils.py

@@ -0,0 +1,67 @@
+from functools import partial
+from ddtrace.utils.importlib import func_name
+
+
+class SomethingCallable(object):
+    """
+    A dummy class that implements __call__().
+    """
+    value = 42
+
+    def __call__(self):
+        return 'something'
+
+    def me(self):
+        return self
+
+    @staticmethod
+    def add(a, b):
+        return a + b
+
+    @classmethod
+    def answer(cls):
+        return cls.value
+
+
+def some_function():
+    """
+    A function doing nothing.
+    """
+    return 'nothing'
+
+
+def minus(a, b):
+    return a - b
+
+
+minus_two = partial(minus, b=2)  # partial funcs need special handling (no module)
+
+# disabling flake8 test below, yes, declaring a func like this is bad, we know
+plus_three = lambda x: x + 3  # noqa: E731
+
+
+class TestContrib(object):
+    """
+    Ensure that contrib utility functions handles corner cases
+    """
+    def test_func_name(self):
+        # check that func_name works on anything callable, not only funcs.
+        assert 'nothing' == some_function()
+        assert 'tests.contrib.test_utils.some_function' == func_name(some_function)
+
+        f = SomethingCallable()
+        assert 'something' == f()
+        assert 'tests.contrib.test_utils.SomethingCallable' == func_name(f)
+
+        assert f == f.me()
+        assert 'tests.contrib.test_utils.me' == func_name(f.me)
+        assert 3 == f.add(1, 2)
+        assert 'tests.contrib.test_utils.add' == func_name(f.add)
+        assert 42 == f.answer()
+        assert 'tests.contrib.test_utils.answer' == func_name(f.answer)
+
+        assert 'tests.contrib.test_utils.minus' == func_name(minus)
+        assert 5 == minus_two(7)
+        assert 'partial' == func_name(minus_two)
+        assert 10 == plus_three(7)
+        assert 'tests.contrib.test_utils.<lambda>' == func_name(plus_three)