Files
alt-glitch 23344a9a3c feat(lsp): plugin-based LSP diagnostics with zero core changes
Ship LSP semantic diagnostics as a bundled plugin (plugins/lsp/) using
existing hook system.  Zero lines of core code modified.

Plugin wiring:
- pre_tool_call: capture LSP baseline before write_file/patch
- transform_tool_result: inject diagnostics into tool result JSON
- on_session_start/on_session_end + atexit: lifecycle management

Key design:
- Baselines keyed by (session_id, abs_path) for concurrent safety
- Diagnostics added as 'lsp_diagnostics' JSON field (preserves shape)
- Per-file workspace detection (no static session-start gate)
- V4A multi-file patch skipped for MVP
- Short timeout (3s) — cold start degrades gracefully
- os.path.exists heuristic for Docker/SSH backend skip
- First relevant write with no server → INFO log with install hint

Tests: 77/77 pass including:
- Protocol framing, reporter formatting, workspace resolution
- Client E2E against mock LSP server (live_system_guard_bypass)
- Eventlog steady-state silence contract
- Backend-gate heuristic (local vs non-local paths)
- Full hook flow integration (pre→write→transform with diagnostics)

Source: PR #24168 by @teknium1, PR #24155 by @OutThisLife
Co-authored-by: Teknium <127238744+teknium1@users.noreply.github.com>
2026-05-12 13:01:13 +00:00

537 lines
20 KiB
Python

"""Service-level orchestration for LSP clients.
The :class:`LSPService` is the bridge between the synchronous
file_operations layer and the async :class:`agent.lsp.client.LSPClient`.
Design choices:
- A **single asyncio event loop** runs in a background thread. All
client work happens on that loop. Synchronous callers from
``tools/file_operations.py`` use :meth:`get_diagnostics_sync` to
open + wait + drain in one blocking call.
- One client per ``(server_id, workspace_root)`` key. Lazy spawn:
the first request for a key spawns the client; subsequent requests
re-use it.
- A **broken-set** records ``(server_id, workspace_root)`` pairs that
failed to spawn or initialize. These are never retried for the
life of the service. Mirrors OpenCode's design.
- A **delta baseline** map keeps "diagnostics-as-of-the-last-snapshot"
per file. ``snapshot_baseline()`` is called BEFORE a write; the
next ``get_diagnostics_sync()`` returns only diagnostics that
weren't in the baseline. This is the lift from Claude Code's
``beforeFileEdited`` / ``getNewDiagnostics`` pattern, except wired
to the local LSP layer instead of MCP IDE RPC.
The service is **off by default** — call :meth:`is_active` to check
whether it's actually doing anything. When LSP is disabled in
config, when no git workspace can be detected, when all configured
servers are missing binaries and auto-install is off, ``is_active``
returns False and the file_operations layer falls through to the
in-process syntax check.
"""
from __future__ import annotations
import asyncio
import logging
import os
import threading
import time
from concurrent.futures import Future as ConcurrentFuture
from typing import Any, Dict, List, Optional, Tuple
from plugins.lsp import eventlog
from plugins.lsp.client import (
DIAGNOSTICS_DOCUMENT_WAIT,
LSPClient,
file_uri,
)
from plugins.lsp.servers import (
ServerContext,
ServerDef,
SpawnSpec,
find_server_for_file,
language_id_for,
)
from plugins.lsp.workspace import (
clear_cache,
is_inside_workspace,
resolve_workspace_for_file,
)
logger = logging.getLogger("agent.lsp.manager")
DEFAULT_IDLE_TIMEOUT = 600 # seconds; servers idle for >10min get reaped
class _BackgroundLoop:
"""A daemon thread that owns one asyncio event loop.
Provides :meth:`run` for synchronous callers — submits a coroutine
to the loop and blocks until it finishes (or a timeout fires).
"""
def __init__(self) -> None:
self._loop: Optional[asyncio.AbstractEventLoop] = None
self._thread: Optional[threading.Thread] = None
self._ready = threading.Event()
def start(self) -> None:
if self._thread is not None:
return
self._thread = threading.Thread(
target=self._run_forever,
name="hermes-lsp-loop",
daemon=True,
)
self._thread.start()
self._ready.wait(timeout=5.0)
def _run_forever(self) -> None:
loop = asyncio.new_event_loop()
self._loop = loop
asyncio.set_event_loop(loop)
self._ready.set()
try:
loop.run_forever()
finally:
try:
loop.close()
except Exception: # noqa: BLE001
pass
def run(self, coro, *, timeout: Optional[float] = None) -> Any:
"""Submit a coroutine to the loop and block until done.
Returns the coroutine's result, or raises its exception.
"""
if self._loop is None:
raise RuntimeError("background loop not started")
fut: ConcurrentFuture = asyncio.run_coroutine_threadsafe(coro, self._loop)
try:
return fut.result(timeout=timeout)
except Exception:
fut.cancel()
raise
def stop(self) -> None:
loop = self._loop
if loop is None:
return
try:
loop.call_soon_threadsafe(loop.stop)
except RuntimeError:
pass
if self._thread is not None:
self._thread.join(timeout=2.0)
self._loop = None
self._thread = None
class LSPService:
"""The process-wide LSP service.
Created once via :meth:`create_from_config`; the
:func:`agent.lsp.get_service` accessor manages the singleton.
Most callers should use that accessor rather than constructing
:class:`LSPService` directly.
"""
# ------------------------------------------------------------------
# construction + factory
# ------------------------------------------------------------------
def __init__(
self,
*,
enabled: bool,
wait_mode: str,
wait_timeout: float,
install_strategy: str,
binary_overrides: Optional[Dict[str, List[str]]] = None,
env_overrides: Optional[Dict[str, Dict[str, str]]] = None,
init_overrides: Optional[Dict[str, Dict[str, Any]]] = None,
disabled_servers: Optional[List[str]] = None,
idle_timeout: float = DEFAULT_IDLE_TIMEOUT,
) -> None:
self._enabled = enabled
self._wait_mode = wait_mode if wait_mode in ("document", "full") else "document"
self._wait_timeout = wait_timeout
self._install_strategy = install_strategy
self._binary_overrides = binary_overrides or {}
self._env_overrides = env_overrides or {}
self._init_overrides = init_overrides or {}
self._disabled_servers = set(disabled_servers or [])
self._idle_timeout = idle_timeout
self._loop = _BackgroundLoop()
if self._enabled:
self._loop.start()
# Per-(server_id, workspace_root) state
self._clients: Dict[Tuple[str, str], LSPClient] = {}
self._broken: set = set()
self._spawning: Dict[Tuple[str, str], asyncio.Future] = {}
self._last_used: Dict[Tuple[str, str], float] = {}
self._state_lock = threading.Lock()
# Delta baseline: file path → snapshot of diagnostics taken
# immediately before a write. ``get_diagnostics_sync`` filters
# out anything in the baseline so the agent only sees errors
# introduced by the current edit.
self._delta_baseline: Dict[str, List[Dict[str, Any]]] = {}
@classmethod
def create_from_config(cls) -> Optional["LSPService"]:
"""Build a service from ``hermes_cli.config`` settings.
Returns ``None`` if the config can't be loaded. The service
itself returns ``is_active()`` False when LSP is disabled.
"""
try:
from hermes_cli.config import load_config
cfg = load_config()
except Exception as e: # noqa: BLE001
logger.debug("LSP config load failed: %s", e)
return None
lsp_cfg = (cfg.get("lsp") or {}) if isinstance(cfg, dict) else {}
if not isinstance(lsp_cfg, dict):
lsp_cfg = {}
enabled = bool(lsp_cfg.get("enabled", True))
wait_mode = lsp_cfg.get("wait_mode", "document")
wait_timeout = float(lsp_cfg.get("wait_timeout", DIAGNOSTICS_DOCUMENT_WAIT))
install_strategy = lsp_cfg.get("install_strategy", "auto")
servers_cfg = lsp_cfg.get("servers") or {}
disabled = []
binary_overrides: Dict[str, List[str]] = {}
env_overrides: Dict[str, Dict[str, str]] = {}
init_overrides: Dict[str, Dict[str, Any]] = {}
if isinstance(servers_cfg, dict):
for name, sub in servers_cfg.items():
if not isinstance(sub, dict):
continue
if sub.get("disabled"):
disabled.append(name)
cmd = sub.get("command")
if isinstance(cmd, list) and cmd:
binary_overrides[name] = cmd
env = sub.get("env")
if isinstance(env, dict):
env_overrides[name] = {k: str(v) for k, v in env.items()}
init = sub.get("initialization_options")
if isinstance(init, dict):
init_overrides[name] = init
return cls(
enabled=enabled,
wait_mode=wait_mode,
wait_timeout=wait_timeout,
install_strategy=install_strategy,
binary_overrides=binary_overrides,
env_overrides=env_overrides,
init_overrides=init_overrides,
disabled_servers=disabled,
)
# ------------------------------------------------------------------
# public API
# ------------------------------------------------------------------
def is_active(self) -> bool:
"""Return True iff this service should be consulted at all."""
return self._enabled
def enabled_for(self, file_path: str) -> bool:
"""Return True iff LSP should run for this specific file.
Gates on workspace detection (file or cwd inside a git worktree)
and on whether any registered server matches the extension.
"""
if not self._enabled:
return False
srv = find_server_for_file(file_path)
if srv is None or srv.server_id in self._disabled_servers:
return False
ws_root, gated_in = resolve_workspace_for_file(file_path)
return bool(ws_root and gated_in)
def snapshot_baseline(self, file_path: str) -> None:
"""Snapshot current diagnostics for ``file_path`` as the delta baseline.
Called BEFORE a write so the next ``get_diagnostics_sync()``
can filter out pre-existing errors. Best-effort — failures
are silently swallowed so a flaky server can't break a write.
"""
if not self.enabled_for(file_path):
return
try:
diags = self._loop.run(self._snapshot_async(file_path), timeout=8.0)
self._delta_baseline[os.path.abspath(file_path)] = diags or []
except Exception as e: # noqa: BLE001
logger.debug("baseline snapshot failed for %s: %s", file_path, e)
# Set empty baseline so the next call still does the
# comparison (any post-edit diagnostic will be considered
# "new" — safe default).
self._delta_baseline[os.path.abspath(file_path)] = []
def get_diagnostics_sync(
self,
file_path: str,
*,
delta: bool = True,
timeout: Optional[float] = None,
) -> List[Dict[str, Any]]:
"""Synchronously open ``file_path`` in the right server, wait for
diagnostics, return them.
If ``delta`` is True (default), the result is filtered against
any baseline previously captured via :meth:`snapshot_baseline`.
Diagnostics present in the baseline are removed so the caller
only sees errors introduced by the current edit.
Returns an empty list when LSP is disabled, when no workspace
can be detected, when no server matches, or when the server
can't be spawned. Never raises.
"""
if not self.enabled_for(file_path):
return []
# Resolve server_id eagerly so we can emit structured logs even
# when the request errors out below.
srv = find_server_for_file(file_path)
server_id = srv.server_id if srv else "?"
try:
t = timeout if timeout is not None else self._wait_timeout + 2.0
diags = self._loop.run(self._open_and_wait_async(file_path), timeout=t) or []
except asyncio.TimeoutError as e:
eventlog.log_timeout(server_id, file_path)
logger.debug("LSP diagnostics timeout for %s: %s", file_path, e)
return []
except Exception as e: # noqa: BLE001
eventlog.log_server_error(server_id, file_path, e)
logger.debug("LSP diagnostics fetch failed for %s: %s", file_path, e)
return []
abs_path = os.path.abspath(file_path)
if delta:
baseline = self._delta_baseline.get(abs_path) or []
if baseline:
seen = {_diag_key(d) for d in baseline}
diags = [d for d in diags if _diag_key(d) not in seen]
# Roll baseline forward — next call returns deltas relative
# to the just-emitted state, mirroring claude-code's
# diagnosticTracking.
try:
fresh = self._loop.run(self._current_diags_async(file_path), timeout=2.0) or []
except Exception: # noqa: BLE001
fresh = []
if fresh:
self._delta_baseline[abs_path] = fresh
if diags:
eventlog.log_diagnostics(server_id, file_path, len(diags))
else:
eventlog.log_clean(server_id, file_path)
return diags
def shutdown(self) -> None:
"""Tear down all clients and stop the background loop."""
if not self._enabled:
return
try:
self._loop.run(self._shutdown_async(), timeout=10.0)
except Exception as e: # noqa: BLE001
logger.debug("LSP shutdown error: %s", e)
self._loop.stop()
clear_cache()
# ------------------------------------------------------------------
# async internals
# ------------------------------------------------------------------
async def _snapshot_async(self, file_path: str) -> List[Dict[str, Any]]:
client = await self._get_or_spawn(file_path)
if client is None:
return []
try:
version = await client.open_file(file_path, language_id=language_id_for(file_path))
await client.wait_for_diagnostics(file_path, version, mode=self._wait_mode)
except Exception as e: # noqa: BLE001
logger.debug("snapshot open/wait failed: %s", e)
return []
self._last_used[(client.server_id, client.workspace_root)] = time.time()
return list(client.diagnostics_for(file_path))
async def _open_and_wait_async(self, file_path: str) -> List[Dict[str, Any]]:
client = await self._get_or_spawn(file_path)
if client is None:
return []
try:
version = await client.open_file(file_path, language_id=language_id_for(file_path))
await client.save_file(file_path)
await client.wait_for_diagnostics(file_path, version, mode=self._wait_mode)
except Exception as e: # noqa: BLE001
logger.debug("open/wait failed for %s: %s", file_path, e)
return []
self._last_used[(client.server_id, client.workspace_root)] = time.time()
return list(client.diagnostics_for(file_path))
async def _current_diags_async(self, file_path: str) -> List[Dict[str, Any]]:
ws, gated = resolve_workspace_for_file(file_path)
srv = find_server_for_file(file_path)
if not (ws and gated and srv):
return []
with self._state_lock:
client = self._clients.get((srv.server_id, ws))
if client is None:
return []
return list(client.diagnostics_for(file_path))
async def _get_or_spawn(self, file_path: str) -> Optional[LSPClient]:
srv = find_server_for_file(file_path)
if srv is None:
return None
if srv.server_id in self._disabled_servers:
eventlog.log_disabled(srv.server_id, file_path, "disabled in config")
return None
ws_root, gated = resolve_workspace_for_file(file_path)
if not (ws_root and gated):
eventlog.log_no_project_root(srv.server_id, file_path)
return None
per_server_root = srv.resolve_root(file_path, ws_root)
if per_server_root is None:
eventlog.log_disabled(
srv.server_id, file_path, "exclude marker hit (server gated off)"
)
return None # exclude marker hit, server gated off
key = (srv.server_id, per_server_root)
if key in self._broken:
return None
with self._state_lock:
client = self._clients.get(key)
if client is not None and client.is_running:
eventlog.log_active(srv.server_id, per_server_root)
return client
spawning = self._spawning.get(key)
if spawning is not None:
try:
return await spawning
except Exception: # noqa: BLE001
return None
# Begin spawn
loop = asyncio.get_running_loop()
spawn_future: asyncio.Future = loop.create_future()
with self._state_lock:
self._spawning[key] = spawn_future
try:
ctx = ServerContext(
workspace_root=per_server_root,
install_strategy=self._install_strategy,
binary_overrides=self._binary_overrides,
env_overrides=self._env_overrides,
init_overrides=self._init_overrides,
)
spec = srv.build_spawn(per_server_root, ctx)
if spec is None:
# ``build_spawn`` returns None when the binary can't be
# located (auto-install disabled, manual-only server,
# or install attempt failed). Surface this once via
# the structured logger so the user can act on it.
eventlog.log_server_unavailable(srv.server_id, srv.server_id)
self._broken.add(key)
spawn_future.set_result(None)
return None
client = LSPClient(
server_id=srv.server_id,
workspace_root=spec.workspace_root,
command=spec.command,
env=spec.env,
cwd=spec.cwd,
initialization_options=spec.initialization_options,
seed_diagnostics_on_first_push=spec.seed_diagnostics_on_first_push or srv.seed_first_push,
)
try:
await client.start()
except Exception as e: # noqa: BLE001
eventlog.log_spawn_failed(srv.server_id, per_server_root, e)
self._broken.add(key)
spawn_future.set_result(None)
return None
with self._state_lock:
self._clients[key] = client
self._last_used[key] = time.time()
eventlog.log_active(srv.server_id, per_server_root)
spawn_future.set_result(client)
return client
finally:
with self._state_lock:
self._spawning.pop(key, None)
async def _shutdown_async(self) -> None:
with self._state_lock:
clients = list(self._clients.values())
self._clients.clear()
self._broken.clear()
self._last_used.clear()
await asyncio.gather(
*(c.shutdown() for c in clients),
return_exceptions=True,
)
# ------------------------------------------------------------------
# status / introspection (used by ``hermes lsp status``)
# ------------------------------------------------------------------
def get_status(self) -> Dict[str, Any]:
"""Return a snapshot of the service for the CLI status command."""
with self._state_lock:
clients = [
{
"server_id": k[0],
"workspace_root": k[1],
"state": c.state,
"running": c.is_running,
}
for k, c in self._clients.items()
]
broken = list(self._broken)
return {
"enabled": self._enabled,
"wait_mode": self._wait_mode,
"wait_timeout": self._wait_timeout,
"install_strategy": self._install_strategy,
"clients": clients,
"broken": broken,
"disabled_servers": sorted(self._disabled_servers),
}
def _diag_key(d: Dict[str, Any]) -> str:
"""Content equality key used for delta filtering. Mirrors
:func:`agent.lsp.client._diagnostic_key`."""
rng = d.get("range") or {}
start = rng.get("start") or {}
end = rng.get("end") or {}
code = d.get("code")
if code is not None and not isinstance(code, str):
code = str(code)
return "\x00".join(
[
str(d.get("severity") or 1),
str(code or ""),
str(d.get("source") or ""),
str(d.get("message") or "").strip(),
f"{start.get('line', 0)}:{start.get('character', 0)}-{end.get('line', 0)}:{end.get('character', 0)}",
]
)
__all__ = ["LSPService"]