Add tests for DISCORD_INVITE regex

Author: GDWR

tests/botcore/utils/test_regex.py

@@ -0,0 +1,48 @@
+from typing import Optional
+
+from botcore.utils.regex import DISCORD_INVITE
+
+
+def use_regex(s: str) -> Optional[str]:
+    """Helper function to run the Regex on a string.
+
+    Return the invite capture group, if the string matches the pattern
+        else return None
+    """
+    result = DISCORD_INVITE.search(s)
+    return result if result is None else result.group("invite")
+
+
+def test_discord_invite_positive():
+    """Test the DISCORD_INVITE regex on a set of strings we would expect to capture."""
+
+    assert use_regex("discord.gg/python") == "python"
+    assert use_regex("https://discord.gg/python") == "python"
+    assert use_regex("discord.com/invite/python") == "python"
+    assert use_regex("discordapp.com/invite/python") == "python"
+    assert use_regex("discord.me/python") == "python"
+    assert use_regex("discord.li/python") == "python"
+    assert use_regex("discord.io/python") == "python"
+    assert use_regex(".gg/python") == "python"
+
+    assert use_regex("discord.gg/python/but/extra") == "python/but/extra"
+    assert use_regex("discord.me/this/isnt/python") == "this/isnt/python"
+    assert use_regex(".gg/a/a/a/a/a/a/a/a/a/a/a") == "a/a/a/a/a/a/a/a/a/a/a"
+    assert use_regex("discordapp.com/invite/python/snakescord") == "python/snakescord"
+    assert use_regex("http://discord.gg/python/%20/notpython") == "python/%20/notpython"
+    assert use_regex("discord.gg/python?=ts/notpython") == "python?=ts/notpython"
+    assert use_regex("https://discord.gg/python#fragment/notpython") == "python#fragment/notpython"
+    assert use_regex("https://discord.gg/python/~/notpython") == "python/~/notpython"
+
+    assert use_regex("https://discord.gg/python with whitespace") == "python"
+    assert use_regex(" https://discord.gg/python ") == "python"
+
+
+def test_discord_invite_negatives():
+    """Test the DISCORD_INVITE regex on a set of strings we would expect to not capture."""
+
+    assert use_regex("another string") is None
+    assert use_regex("https://pythondiscord.com") is None
+    assert use_regex("https://discord.com") is None
+    assert use_regex("https://discord.gg") is None
+    assert use_regex("https://discord.gg/ python") is None