feat: add !paste command and unit tests for 5 core plugins

Add cmd_paste to flaskpaste plugin (create paste, return URL).
Add test suites for encode, hash, defang, cidr, and dns plugins
(83 new test cases, 1093 total).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_defang.py

@@ -0,0 +1,147 @@
+"""Tests for the defang/refang plugin."""
+
+import asyncio
+import importlib.util
+import sys
+from pathlib import Path
+
+from derp.irc import Message
+
+# plugins/ is not a Python package -- load the module from file path
+_spec = importlib.util.spec_from_file_location(
+    "plugins.defang", Path(__file__).resolve().parent.parent / "plugins" / "defang.py",
+)
+_mod = importlib.util.module_from_spec(_spec)
+sys.modules[_spec.name] = _mod
+_spec.loader.exec_module(_mod)
+
+from plugins.defang import (  # noqa: E402
+    _defang,
+    _refang,
+    cmd_defang,
+    cmd_refang,
+)
+
+# -- Helpers -----------------------------------------------------------------
+
+class _FakeBot:
+    def __init__(self):
+        self.replied: list[str] = []
+
+    async def reply(self, message, text: str) -> None:
+        self.replied.append(text)
+
+
+def _msg(text: str) -> Message:
+    return Message(
+        raw="", prefix="alice!~alice@host", nick="alice",
+        command="PRIVMSG", params=["#test", text], tags={},
+    )
+
+
+# -- Pure function: _defang --------------------------------------------------
+
+class TestDefangFunction:
+    def test_http_url(self):
+        result = _defang("http://evil.com")
+        assert "[://]" in result
+
+    def test_https_url(self):
+        result = _defang("https://evil.com/path")
+        assert "[://]" in result
+
+    def test_ftp_url(self):
+        result = _defang("ftp://files.evil.com")
+        assert "ftp[://]" in result
+
+    def test_ip_address(self):
+        assert _defang("192.168.1.1") == "192[.]168[.]1[.]1"
+
+    def test_path_dots_preserved(self):
+        result = _defang("http://evil.com/file.php?q=1")
+        assert "[://]" in result
+        assert "file.php" in result
+
+    def test_domain_only(self):
+        assert _defang("evil.com") == "evil[.]com"
+
+
+# -- Pure function: _refang --------------------------------------------------
+
+class TestRefangFunction:
+    def test_basic(self):
+        assert _refang("evil[.]com") == "evil.com"
+
+    def test_protocol(self):
+        assert _refang("http[://]evil[.]com") == "http://evil.com"
+
+    def test_hxxp(self):
+        assert _refang("hxxps[://]evil[.]com") == "https://evil.com"
+
+    def test_hXXp(self):
+        assert _refang("hXXps[://]evil[.]com") == "https://evil.com"
+
+    def test_at_sign(self):
+        assert _refang("user[at]evil[.]com") == "user@evil.com"
+
+    def test_at_uppercase(self):
+        assert _refang("user[AT]evil[.]com") == "user@evil.com"
+
+
+# -- Roundtrip ---------------------------------------------------------------
+
+class TestRoundtrip:
+    def test_ip(self):
+        original = "10.0.0.1"
+        defanged = _defang(original)
+        refanged = _refang(defanged)
+        assert refanged == original
+
+    def test_domain(self):
+        original = "evil.com"
+        defanged = _defang(original)
+        assert "[.]" in defanged
+        refanged = _refang(defanged)
+        assert refanged == original
+
+    def test_refang_hxxp(self):
+        """Refang handles hxxp notation not produced by _defang."""
+        assert _refang("hxxps://evil[.]com") == "https://evil.com"
+
+
+# -- Command: defang ---------------------------------------------------------
+
+class TestCmdDefang:
+    def test_url(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_defang(bot, _msg("!defang https://evil.com/path")))
+        assert "[://]" in bot.replied[0]
+
+    def test_ip(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_defang(bot, _msg("!defang 192.168.1.1")))
+        assert bot.replied[0] == "192[.]168[.]1[.]1"
+
+    def test_missing_args(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_defang(bot, _msg("!defang")))
+        assert "Usage" in bot.replied[0]
+
+
+# -- Command: refang ---------------------------------------------------------
+
+class TestCmdRefang:
+    def test_url(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_refang(bot, _msg("!refang hxxps[://]evil[.]com")))
+        assert bot.replied[0] == "https://evil.com"
+
+    def test_ip(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_refang(bot, _msg("!refang 10[.]0[.]0[.]1")))
+        assert bot.replied[0] == "10.0.0.1"
+
+    def test_missing_args(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_refang(bot, _msg("!refang")))
+        assert "Usage" in bot.replied[0]