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_encode.py

@@ -0,0 +1,141 @@
+"""Tests for the encode/decode 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.encode", Path(__file__).resolve().parent.parent / "plugins" / "encode.py",
+)
+_mod = importlib.util.module_from_spec(_spec)
+sys.modules[_spec.name] = _mod
+_spec.loader.exec_module(_mod)
+
+from plugins.encode import cmd_decode, cmd_encode  # noqa: E402
+
+# -- 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={},
+    )
+
+
+# -- Encode ------------------------------------------------------------------
+
+class TestEncodeB64:
+    def test_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode b64 hello")))
+        assert bot.replied[0] == "aGVsbG8="
+
+    def test_decode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode b64 aGVsbG8=")))
+        assert bot.replied[0] == "hello"
+
+    def test_roundtrip(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode b64 test data")))
+        encoded = bot.replied[0]
+        asyncio.run(cmd_decode(bot, _msg(f"!decode b64 {encoded}")))
+        assert bot.replied[1] == "test data"
+
+
+class TestEncodeHex:
+    def test_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode hex hello")))
+        assert bot.replied[0] == "68656c6c6f"
+
+    def test_decode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode hex 68656c6c6f")))
+        assert bot.replied[0] == "hello"
+
+    def test_decode_invalid(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode hex zzzz")))
+        assert "error" in bot.replied[0].lower()
+
+
+class TestEncodeUrl:
+    def test_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode url hello world")))
+        assert bot.replied[0] == "hello%20world"
+
+    def test_decode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode url hello%20world")))
+        assert bot.replied[0] == "hello world"
+
+    def test_special_chars(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode url a=1&b=2")))
+        assert "%3D" in bot.replied[0]
+        assert "%26" in bot.replied[0]
+
+
+class TestEncodeRot13:
+    def test_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode rot13 hello")))
+        assert bot.replied[0] == "uryyb"
+
+    def test_roundtrip(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode rot13 secret")))
+        encoded = bot.replied[0]
+        asyncio.run(cmd_decode(bot, _msg(f"!decode rot13 {encoded}")))
+        assert bot.replied[1] == "secret"
+
+
+class TestEncodeErrors:
+    def test_unknown_format_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode bad hello")))
+        assert "Unknown format" in bot.replied[0]
+
+    def test_unknown_format_decode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode bad hello")))
+        assert "Unknown format" in bot.replied[0]
+
+    def test_missing_args_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode")))
+        assert "Usage" in bot.replied[0]
+
+    def test_missing_args_decode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode")))
+        assert "Usage" in bot.replied[0]
+
+    def test_missing_text_encode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_encode(bot, _msg("!encode b64")))
+        assert "Usage" in bot.replied[0]
+
+    def test_missing_text_decode(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode hex")))
+        assert "Usage" in bot.replied[0]
+
+    def test_decode_b64_invalid(self):
+        bot = _FakeBot()
+        asyncio.run(cmd_decode(bot, _msg("!decode b64 !!!invalid!!!")))
+        assert "error" in bot.replied[0].lower()