Add tests for `in_whitelisted_context` decorator

I have added tests for the new `in_whitelisted_context` decorator. They work by calling the decorator with different kwargs to generate a specific predicate callable. That callable is then called to assess if it comes to the right conclusion.

1 files changed, 115 insertions, 0 deletions

diff --git a/tests/bot/test_decorators.py b/tests/bot/test_decorators.py
new file mode 100644
index 000000000..fae7c0c52
--- /dev/null
+++ b/tests/bot/test_decorators.py
@@ -0,0 +1,115 @@
+import collections
+import unittest
+import unittest.mock
+
+from bot.decorators import InWhitelistedContextCheckFailure, in_whitelisted_context
+from tests import helpers
+
+
+WhitelistedContextTestCase = collections.namedtuple("WhitelistedContextTestCase", ("kwargs", "ctx"))
+
+
+class InWhitelistedContextTests(unittest.TestCase):
+    """Tests for the `in_whitelisted_context` check."""
+
+    @classmethod
+    def setUpClass(cls):
+        """Set up helpers that only need to be defined once."""
+        cls.bot_commands = helpers.MockTextChannel(id=123456789, category_id=123456)
+        cls.help_channel = helpers.MockTextChannel(id=987654321, category_id=987654)
+        cls.non_whitelisted_channel = helpers.MockTextChannel(id=666666)
+
+        cls.non_staff_member = helpers.MockMember()
+        cls.staff_role = helpers.MockRole(id=121212)
+        cls.staff_member = helpers.MockMember(roles=(cls.staff_role,))
+
+        cls.whitelisted_channels = (cls.bot_commands.id,)
+        cls.whitelisted_categories = (cls.help_channel.category_id,)
+        cls.whitelisted_roles = (cls.staff_role.id,)
+
+    def test_predicate_returns_true_for_whitelisted_context(self):
+        """The predicate should return `True` if a whitelisted context was passed to it."""
+        test_cases = (
+            # Commands issued in whitelisted channels by members without whitelisted roles
+            WhitelistedContextTestCase(
+                kwargs={"whitelisted_channels": self.whitelisted_channels},
+                ctx=helpers.MockContext(channel=self.bot_commands, author=self.non_staff_member)
+            ),
+            # `redirect_channel` should be added implicitly to the `whitelisted_channels`
+            WhitelistedContextTestCase(
+                kwargs={"redirect_channel": self.bot_commands.id},
+                ctx=helpers.MockContext(channel=self.bot_commands, author=self.non_staff_member)
+            ),
+
+            # Commands issued in a whitelisted category by members without whitelisted roles
+            WhitelistedContextTestCase(
+                kwargs={"whitelisted_categories": self.whitelisted_categories},
+                ctx=helpers.MockContext(channel=self.help_channel, author=self.non_staff_member)
+            ),
+
+            # Command issued by a staff member in a non-whitelisted channel/category
+            WhitelistedContextTestCase(
+                kwargs={"whitelisted_roles": self.whitelisted_roles},
+                ctx=helpers.MockContext(channel=self.non_whitelisted_channel, author=self.staff_member)
+            ),
+
+            # With all kwargs provided
+            WhitelistedContextTestCase(
+                kwargs={
+                    "whitelisted_channels": self.whitelisted_channels,
+                    "whitelisted_categories": self.whitelisted_categories,
+                    "whitelisted_roles": self.whitelisted_roles,
+                    "redirect_channel": self.bot_commands,
+                },
+                ctx=helpers.MockContext(channel=self.help_channel, author=self.staff_member)
+            ),
+        )
+
+        for test_case in test_cases:
+            # patch `commands.check` with a no-op lambda that just returns the predicate passed to it
+            # so we can test the predicate that was generated from the specified kwargs.
+            with unittest.mock.patch("bot.decorators.commands.check", new=lambda predicate: predicate):
+                predicate = in_whitelisted_context(**test_case.kwargs)
+
+            with self.subTest(test_case=test_case):
+                self.assertTrue(predicate(test_case.ctx))
+
+    def test_predicate_raises_exception_for_non_whitelisted_context(self):
+        """The predicate should raise `InWhitelistedContextCheckFailure` for a non-whitelisted context."""
+        test_cases = (
+            # Failing check with `redirect_channel`
+            WhitelistedContextTestCase(
+                kwargs={
+                    "whitelisted_categories": self.whitelisted_categories,
+                    "whitelisted_channels": self.whitelisted_channels,
+                    "whitelisted_roles": self.whitelisted_roles,
+                    "redirect_channel": self.bot_commands.id,
+                },
+                ctx=helpers.MockContext(channel=self.non_whitelisted_channel, author=self.non_staff_member)
+            ),
+
+            # Failing check without `redirect_channel`
+            WhitelistedContextTestCase(
+                kwargs={
+                    "whitelisted_categories": self.whitelisted_categories,
+                    "whitelisted_channels": self.whitelisted_channels,
+                    "whitelisted_roles": self.whitelisted_roles,
+                },
+                ctx=helpers.MockContext(channel=self.non_whitelisted_channel, author=self.non_staff_member)
+            ),
+        )
+
+        for test_case in test_cases:
+            # Create expected exception message based on whether or not a redirect channel was provided
+            expected_message = "Sorry, but you are not allowed to use that command here."
+            if test_case.kwargs.get("redirect_channel"):
+                expected_message += f" Please use the <#{test_case.kwargs['redirect_channel']}> channel instead."
+
+            # patch `commands.check` with a no-op lambda that just returns the predicate passed to it
+            # so we can test the predicate that was generated from the specified kwargs.
+            with unittest.mock.patch("bot.decorators.commands.check", new=lambda predicate: predicate):
+                predicate = in_whitelisted_context(**test_case.kwargs)
+
+            with self.subTest(test_case=test_case):
+                with self.assertRaises(InWhitelistedContextCheckFailure, msg=expected_message):
+                    predicate(test_case.ctx)