feat: paste overflow via FlaskPaste for long replies

Add Bot.long_reply() that sends lines directly when under threshold,
or creates a FlaskPaste paste with preview + link when over. Refactor
abuseipdb, alert history, crtsh, dork, exploitdb, and subdomain
plugins to use long_reply(). Configurable paste_threshold (default: 4).

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

tests/test_paste_overflow.py

@@ -0,0 +1,175 @@
+"""Tests for Bot.long_reply() paste overflow behaviour."""
+
+import asyncio
+import types
+
+from derp.bot import Bot
+from derp.irc import Message
+from derp.plugin import PluginRegistry
+
+# -- Helpers -----------------------------------------------------------------
+
+def _make_bot(*, paste_threshold: int = 4, flaskpaste_mod=None) -> Bot:
+    """Build a Bot with minimal config and a captured send log."""
+    config = {
+        "server": {
+            "host": "localhost", "port": 6667, "tls": False,
+            "nick": "testbot", "user": "testbot", "realname": "test",
+        },
+        "bot": {
+            "prefix": "!",
+            "channels": ["#test"],
+            "plugins_dir": "plugins",
+            "rate_limit": 100.0,
+            "rate_burst": 100,
+            "paste_threshold": paste_threshold,
+            "admins": [],
+        },
+    }
+    registry = PluginRegistry()
+    if flaskpaste_mod is not None:
+        registry._modules["flaskpaste"] = flaskpaste_mod
+    bot = Bot(config, registry)
+    bot._sent: list[tuple[str, str]] = []  # type: ignore[attr-defined]
+
+    async def _capturing_send(target: str, text: str) -> None:
+        bot._sent.append((target, text))
+
+    bot.send = _capturing_send  # type: ignore[assignment]
+    return bot
+
+
+def _msg(text: str = "", target: str = "#test", nick: str = "alice") -> Message:
+    """Create a channel PRIVMSG."""
+    return Message(
+        raw="", prefix=f"{nick}!~{nick}@host", nick=nick,
+        command="PRIVMSG", params=[target, text], tags={},
+    )
+
+
+def _pm(text: str = "", nick: str = "alice") -> Message:
+    """Create a private PRIVMSG (target = bot nick)."""
+    return Message(
+        raw="", prefix=f"{nick}!~{nick}@host", nick=nick,
+        command="PRIVMSG", params=["testbot", text], tags={},
+    )
+
+
+def _make_fp_mod(*, paste_url: str | None = "https://paste.example/abc"):
+    """Build a fake flaskpaste module with create_paste()."""
+    mod = types.ModuleType("flaskpaste")
+    mod.create_paste = lambda bot, content: paste_url  # type: ignore[attr-defined]
+    return mod
+
+
+# -- Tests -------------------------------------------------------------------
+
+class TestShortReply:
+    def test_sends_all(self):
+        """Lines <= threshold are sent individually, no paste."""
+        bot = _make_bot(paste_threshold=4)
+        msg = _msg()
+        lines = ["line 1", "line 2", "line 3"]
+        asyncio.run(bot.long_reply(msg, lines))
+        assert len(bot._sent) == 3
+        assert bot._sent[0] == ("#test", "line 1")
+        assert bot._sent[1] == ("#test", "line 2")
+        assert bot._sent[2] == ("#test", "line 3")
+
+
+class TestLongReply:
+    def test_creates_paste(self):
+        """Lines > threshold creates paste, sends preview + URL."""
+        fp = _make_fp_mod(paste_url="https://paste.example/xyz")
+        bot = _make_bot(paste_threshold=3, flaskpaste_mod=fp)
+        msg = _msg()
+        lines = ["line 1", "line 2", "line 3", "line 4", "line 5"]
+        asyncio.run(bot.long_reply(msg, lines, label="results"))
+        # preview_count = min(2, threshold-1) = min(2, 2) = 2
+        assert len(bot._sent) == 3
+        assert bot._sent[0] == ("#test", "line 1")
+        assert bot._sent[1] == ("#test", "line 2")
+        assert "3 more lines" in bot._sent[2][1]
+        assert "(results)" in bot._sent[2][1]
+        assert "https://paste.example/xyz" in bot._sent[2][1]
+
+    def test_fallback_no_flaskpaste(self):
+        """No flaskpaste module loaded -- falls back to sending all lines."""
+        bot = _make_bot(paste_threshold=2)
+        msg = _msg()
+        lines = ["a", "b", "c", "d"]
+        asyncio.run(bot.long_reply(msg, lines))
+        assert len(bot._sent) == 4
+        assert [t for _, t in bot._sent] == ["a", "b", "c", "d"]
+
+    def test_fallback_paste_fails(self):
+        """create_paste returns None -- falls back to sending all lines."""
+        fp = _make_fp_mod(paste_url=None)
+        bot = _make_bot(paste_threshold=2, flaskpaste_mod=fp)
+        msg = _msg()
+        lines = ["a", "b", "c"]
+        asyncio.run(bot.long_reply(msg, lines))
+        assert len(bot._sent) == 3
+        assert [t for _, t in bot._sent] == ["a", "b", "c"]
+
+    def test_label_in_overflow_message(self):
+        """Label appears in the overflow message."""
+        fp = _make_fp_mod()
+        bot = _make_bot(paste_threshold=2, flaskpaste_mod=fp)
+        msg = _msg()
+        lines = ["a", "b", "c"]
+        asyncio.run(bot.long_reply(msg, lines, label="history"))
+        overflow = bot._sent[-1][1]
+        assert "(history)" in overflow
+
+    def test_no_label(self):
+        """Overflow message omits label suffix when label is empty."""
+        fp = _make_fp_mod()
+        bot = _make_bot(paste_threshold=2, flaskpaste_mod=fp)
+        msg = _msg()
+        lines = ["a", "b", "c"]
+        asyncio.run(bot.long_reply(msg, lines))
+        overflow = bot._sent[-1][1]
+        assert "more lines:" in overflow
+        assert "()" not in overflow
+
+
+class TestThreshold:
+    def test_configurable(self):
+        """Custom threshold from config controls overflow point."""
+        fp = _make_fp_mod()
+        bot = _make_bot(paste_threshold=10, flaskpaste_mod=fp)
+        msg = _msg()
+
+        # 10 lines == threshold -> no paste
+        lines_at = [f"line {i}" for i in range(10)]
+        asyncio.run(bot.long_reply(msg, lines_at))
+        assert len(bot._sent) == 10
+
+    def test_over_threshold_pastes(self):
+        """Lines exceeding threshold triggers paste."""
+        fp = _make_fp_mod()
+        bot = _make_bot(paste_threshold=10, flaskpaste_mod=fp)
+        msg = _msg()
+        lines_over = [f"line {i}" for i in range(11)]
+        asyncio.run(bot.long_reply(msg, lines_over))
+        assert len(bot._sent) == 3  # 2 preview + overflow msg
+
+
+class TestEdgeCases:
+    def test_empty_lines_noop(self):
+        """Empty list produces no output."""
+        bot = _make_bot()
+        msg = _msg()
+        asyncio.run(bot.long_reply(msg, []))
+        assert bot._sent == []
+
+    def test_pm_uses_nick(self):
+        """Private messages use nick as target."""
+        bot = _make_bot(paste_threshold=4)
+        msg = _pm()
+        lines = ["x", "y"]
+        asyncio.run(bot.long_reply(msg, lines))
+        assert len(bot._sent) == 2
+        assert bot._sent[0] == ("alice", "x")
+        assert bot._sent[1] == ("alice", "y")