Move DD code into its own directory (#6)

reference/tests/test_utils.py

@@ -0,0 +1,98 @@
+import os
+import unittest
+import warnings
+
+from ddtrace.utils.deprecation import deprecation, deprecated, format_message
+from ddtrace.utils.formats import asbool, get_env, flatten_dict
+
+
+class TestUtils(unittest.TestCase):
+    def test_asbool(self):
+        # ensure the value is properly cast
+        self.assertTrue(asbool('True'))
+        self.assertTrue(asbool('true'))
+        self.assertTrue(asbool('1'))
+        self.assertFalse(asbool('False'))
+        self.assertFalse(asbool('false'))
+        self.assertFalse(asbool(None))
+        self.assertFalse(asbool(''))
+        self.assertTrue(asbool(True))
+        self.assertFalse(asbool(False))
+
+    def test_get_env(self):
+        # ensure `get_env` returns a default value if environment variables
+        # are not set
+        value = get_env('django', 'distributed_tracing')
+        self.assertIsNone(value)
+        value = get_env('django', 'distributed_tracing', False)
+        self.assertFalse(value)
+
+    def test_get_env_found(self):
+        # ensure `get_env` returns a value if the environment variable is set
+        os.environ['DD_REQUESTS_DISTRIBUTED_TRACING'] = '1'
+        value = get_env('requests', 'distributed_tracing')
+        self.assertEqual(value, '1')
+
+    def test_get_env_found_legacy(self):
+        # ensure `get_env` returns a value if legacy environment variables
+        # are used, raising a Deprecation warning
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            os.environ['DATADOG_REQUESTS_DISTRIBUTED_TRACING'] = '1'
+            value = get_env('requests', 'distributed_tracing')
+            self.assertEqual(value, '1')
+            self.assertEqual(len(w), 1)
+            self.assertTrue(issubclass(w[-1].category, DeprecationWarning))
+            self.assertTrue('Use `DD_` prefix instead' in str(w[-1].message))
+
+    def test_get_env_key_priority(self):
+        # ensure `get_env` use `DD_` with highest priority
+        os.environ['DD_REQUESTS_DISTRIBUTED_TRACING'] = 'highest'
+        os.environ['DATADOG_REQUESTS_DISTRIBUTED_TRACING'] = 'lowest'
+        value = get_env('requests', 'distributed_tracing')
+        self.assertEqual(value, 'highest')
+
+    def test_deprecation_formatter(self):
+        # ensure the formatter returns the proper message
+        msg = format_message(
+            'deprecated_function',
+            'use something else instead',
+            '1.0.0',
+        )
+        expected = (
+            '\'deprecated_function\' is deprecated and will be remove in future versions (1.0.0). '
+            'use something else instead'
+        )
+        self.assertEqual(msg, expected)
+
+    def test_deprecation(self):
+        # ensure `deprecation` properly raise a DeprecationWarning
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            deprecation(
+                name='fn',
+                message='message',
+                version='1.0.0'
+            )
+            self.assertEqual(len(w), 1)
+            self.assertTrue(issubclass(w[-1].category, DeprecationWarning))
+            self.assertIn('message', str(w[-1].message))
+
+    def test_deprecated_decorator(self):
+        # ensure `deprecated` decorator properly raise a DeprecationWarning
+        @deprecated('decorator', version='1.0.0')
+        def fxn():
+            pass
+
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            fxn()
+            self.assertEqual(len(w), 1)
+            self.assertTrue(issubclass(w[-1].category, DeprecationWarning))
+            self.assertIn('decorator', str(w[-1].message))
+
+    def test_flatten_dict(self):
+        """ ensure that flattening of a nested dict results in a normalized, 1-level dict """
+        d = dict(A=1, B=2, C=dict(A=3, B=4, C=dict(A=5, B=6)))
+        e = dict(A=1, B=2, C_A=3, C_B=4, C_C_A=5, C_C_B=6)
+        self.assertEquals(flatten_dict(d, sep='_'), e)