feat: add /plan command (#1372)

* feat: add /plan command

* refactor: back /plan with bundled skill

* docs: document /plan skill

tests/gateway/test_plan_command.py

@@ -0,0 +1,128 @@
+"""Tests for the /plan gateway slash command."""
+
+from datetime import datetime
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from agent.skill_commands import scan_skill_commands
+from gateway.config import GatewayConfig, Platform, PlatformConfig
+from gateway.platforms.base import MessageEvent
+from gateway.session import SessionEntry, SessionSource
+
+
+def _make_runner():
+    from gateway.run import GatewayRunner
+
+    runner = object.__new__(GatewayRunner)
+    runner.config = GatewayConfig(
+        platforms={Platform.TELEGRAM: PlatformConfig(enabled=True, token="***")}
+    )
+    runner.adapters = {}
+    runner._voice_mode = {}
+    runner.hooks = SimpleNamespace(emit=AsyncMock(), loaded_hooks=False)
+    runner.session_store = MagicMock()
+    runner.session_store.get_or_create_session.return_value = SessionEntry(
+        session_key="agent:main:telegram:dm:c1:u1",
+        session_id="sess-1",
+        created_at=datetime.now(),
+        updated_at=datetime.now(),
+        platform=Platform.TELEGRAM,
+        chat_type="dm",
+    )
+    runner.session_store.load_transcript.return_value = []
+    runner.session_store.has_any_sessions.return_value = True
+    runner.session_store.append_to_transcript = MagicMock()
+    runner.session_store.rewrite_transcript = MagicMock()
+    runner._running_agents = {}
+    runner._pending_messages = {}
+    runner._pending_approvals = {}
+    runner._session_db = None
+    runner._reasoning_config = None
+    runner._provider_routing = {}
+    runner._fallback_model = None
+    runner._show_reasoning = False
+    runner._is_user_authorized = lambda _source: True
+    runner._set_session_env = lambda _context: None
+    runner._run_agent = AsyncMock(
+        return_value={
+            "final_response": "planned",
+            "messages": [],
+            "tools": [],
+            "history_offset": 0,
+            "last_prompt_tokens": 0,
+        }
+    )
+    return runner
+
+
+def _make_event(text="/plan"):
+    return MessageEvent(
+        text=text,
+        source=SessionSource(
+            platform=Platform.TELEGRAM,
+            user_id="u1",
+            chat_id="c1",
+            user_name="tester",
+            chat_type="dm",
+        ),
+        message_id="m1",
+    )
+
+
+def _make_plan_skill(skills_dir):
+    skill_dir = skills_dir / "plan"
+    skill_dir.mkdir(parents=True, exist_ok=True)
+    (skill_dir / "SKILL.md").write_text(
+        """---
+name: plan
+description: Plan mode skill.
+---
+
+# Plan
+
+Use the current conversation context when no explicit instruction is provided.
+Save plans under $HERMES_HOME/plans.
+"""
+    )
+
+
+class TestGatewayPlanCommand:
+    @pytest.mark.asyncio
+    async def test_plan_command_loads_skill_and_runs_agent(self, monkeypatch, tmp_path):
+        import gateway.run as gateway_run
+
+        runner = _make_runner()
+        event = _make_event("/plan Add OAuth login")
+
+        monkeypatch.setenv("HERMES_HOME", str(tmp_path))
+        monkeypatch.setattr(gateway_run, "_resolve_runtime_agent_kwargs", lambda: {"api_key": "***"})
+        monkeypatch.setattr(
+            "agent.model_metadata.get_model_context_length",
+            lambda *_args, **_kwargs: 100_000,
+        )
+
+        with patch("tools.skills_tool.SKILLS_DIR", tmp_path):
+            _make_plan_skill(tmp_path)
+            scan_skill_commands()
+            result = await runner._handle_message(event)
+
+        assert result == "planned"
+        forwarded = runner._run_agent.call_args.kwargs["message"]
+        assert "Plan mode skill" in forwarded
+        assert "Add OAuth login" in forwarded
+        assert str(tmp_path / "plans") in forwarded
+        assert "Runtime note:" in forwarded
+
+    @pytest.mark.asyncio
+    async def test_plan_command_appears_in_help_output_via_skill_listing(self, tmp_path):
+        runner = _make_runner()
+        event = _make_event("/help")
+
+        with patch("tools.skills_tool.SKILLS_DIR", tmp_path):
+            _make_plan_skill(tmp_path)
+            scan_skill_commands()
+            result = await runner._handle_help_command(event)
+
+        assert "/plan" in result