feat(lsp): 支持 ping 并宽容未知协议方法

健康检查在 initialize 前即可响应；未知请求记录 stderr 后返回 null，未知通知记录后忽略，避免插件因 MethodNotFound 判定服务端故障。

App/lib/lsp/LspServer.vp

@@ -247,6 +247,59 @@ def _HandlePosition(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
     return LspRpc.WriteResponse(pool, tr, id_node, result)
 
 
+def _IsPingMethod(method: str) -> int:
+    """Health checks used by plugins; answered before initialize so a probe can never block startup."""
+    if method is None:
+        return 0
+    if string.strcmp(method, "$/ping") == 0:
+        return 1
+    if string.strcmp(method, "ping") == 0:
+        return 1
+    if string.strcmp(method, "viper/ping") == 0:
+        return 1
+    if string.strcmp(method, "viper/pingCompiler") == 0:
+        return 1
+    if string.strcmp(method, "$/health") == 0:
+        return 1
+    if string.strcmp(method, "$/healthcheck") == 0:
+        return 1
+    if string.strcmp(method, "health") == 0:
+        return 1
+    return 0
+
+
+def _IsQuietNotification(method: str) -> int:
+    """Client notifications that this server accepts without action and without logging."""
+    if method is None:
+        return 0
+    if string.strcmp(method, "$/cancelRequest") == 0:
+        return 1
+    if string.strcmp(method, "$/setTrace") == 0:
+        return 1
+    if string.strcmp(method, "window/workDoneProgress/cancel") == 0:
+        return 1
+    if string.strcmp(method, "workspace/didChangeConfiguration") == 0:
+        return 1
+    if string.strcmp(method, "workspace/didChangeWatchedFiles") == 0:
+        return 1
+    if string.strcmp(method, "textDocument/willSave") == 0:
+        return 1
+    return 0
+
+
+def _WritePingResult(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
+                     id_node: json.JsonValue*) -> int:
+    if id_node is None:
+        return 0
+    result: json.JsonValue* = json.object(pool)
+    if result is None:
+        return -1
+    json.object_set(pool, result, "status", json.string_val(pool, "ok"))
+    json.object_set(pool, result, "server", json.string_val(pool, LSP_SERVER_NAME))
+    json.object_set(pool, result, "version", json.string_val(pool, LSP_SERVER_VERSION))
+    return LspRpc.WriteResponse(pool, tr, id_node, result)
+
+
 def Run(pool: memhub.MemBuddy*, perm_pool: memhub.MemBuddy*) -> int:
     os._mbuddy = perm_pool
     os._win32._mbuddy = perm_pool
@@ -301,7 +354,9 @@ def Run(pool: memhub.MemBuddy*, perm_pool: memhub.MemBuddy*) -> int:
 
         params: json.JsonValue* = msg["params"]
         rc: int = 0
-        if string.strcmp(method, LspProtocol.LSP_METHOD_INITIALIZE) == 0:
+        if _IsPingMethod(method) != 0:
+            rc = _WritePingResult(pool, tr, id_node)
+        elif string.strcmp(method, LspProtocol.LSP_METHOD_INITIALIZE) == 0:
             rc = _HandleInitialize(pool, tr, ws, id_node, params)
         elif string.strcmp(method, LspProtocol.LSP_METHOD_INITIALIZED) == 0:
             pass
@@ -322,6 +377,12 @@ def Run(pool: memhub.MemBuddy*, perm_pool: memhub.MemBuddy*) -> int:
             rc = LspNavigation.WorkspaceSymbol(pool, tr, docs, ws, id_node, params)
         elif string.strcmp(method, "textDocument/definition") == 0:
             rc = LspNavigation.Definition(pool, tr, docs, ws, id_node, params)
+        elif string.strcmp(method, "textDocument/declaration") == 0:
+            rc = LspNavigation.Definition(pool, tr, docs, ws, id_node, params)
+        elif string.strcmp(method, "textDocument/typeDefinition") == 0:
+            rc = LspNavigation.Definition(pool, tr, docs, ws, id_node, params)
+        elif string.strcmp(method, "textDocument/implementation") == 0:
+            rc = LspNavigation.Definition(pool, tr, docs, ws, id_node, params)
         elif string.strcmp(method, "textDocument/references") == 0:
             rc = LspNavigation.References(pool, tr, docs, ws, id_node, params)
         elif string.strcmp(method, "textDocument/documentHighlight") == 0:
@@ -339,11 +400,19 @@ def Run(pool: memhub.MemBuddy*, perm_pool: memhub.MemBuddy*) -> int:
             rc = LspRpc.WriteResponse(pool, tr, id_node, json.null(pool))
         elif string.strcmp(method, LspProtocol.LSP_METHOD_EXIT) == 0:
             return 0 if shutdown_requested != 0 else 1
+        elif _IsQuietNotification(method) != 0:
+            pass
+        elif id_node is not None:
+            # LSP clients treat MethodNotFound as a broken server. Unsupported features reply with a
+            # valid empty result and are reported on stderr instead, so the editor keeps working.
+            LspTransport.StderrWrite("viperc-lsp: unsupported request '")
+            LspTransport.StderrWrite(method)
+            LspTransport.StderrWrite("' (answered with null)\n")
+            rc = LspRpc.WriteResponse(pool, tr, id_node, json.null(pool))
         else:
-            if id_node is not None:
-                rc = LspRpc.WriteError(pool, tr, id_node,
-                                       LspProtocol.LSP_ERROR_METHOD_NOT_FOUND,
-                                       "Method not found")
+            LspTransport.StderrWrite("viperc-lsp: ignored notification '")
+            LspTransport.StderrWrite(method)
+            LspTransport.StderrWrite("'\n")
 
         if rc != 0:
             return 1

Tools/lsp/probe.py

@@ -121,6 +121,15 @@ class Client:
 
 def lifecycle(exe: str) -> int:
     client = Client(exe)
+    # A health probe must answer before initialize; plugins use it to confirm the server is alive.
+    for method in ("$/ping", "viper/ping", "ping"):
+        ping = client.request(method, {})
+        ping_result = ping.get("result")
+        if not isinstance(ping_result, dict) or ping_result.get("status") != "ok":
+            raise AssertionError(f"{method} did not return an ok result: {ping}")
+        if ping_result.get("server") != "viperc-lsp":
+            raise AssertionError(f"{method} returned the wrong server name: {ping}")
+
     response = client.request("initialize", {"processId": os.getpid(), "capabilities": {}})
     result = response.get("result")
     if not isinstance(result, dict):
@@ -134,10 +143,24 @@ def lifecycle(exe: str) -> int:
 
     client.notify("initialized", {})
 
+    # Unsupported features must not surface as protocol errors to the client.
     unknown = client.request("unknown/method", {})
-    error = unknown.get("error")
-    if not isinstance(error, dict) or error.get("code") != -32601:
-        raise AssertionError(f"unknown method did not return MethodNotFound: {unknown}")
+    if "error" in unknown:
+        raise AssertionError(f"unknown method returned an error: {unknown}")
+    if "result" not in unknown or unknown.get("result") is not None:
+        raise AssertionError(f"unknown method did not return a null result: {unknown}")
+
+    unsupported = client.request(
+        "textDocument/completion",
+        {"textDocument": {"uri": "file:///unsupported.vp"}, "position": {"line": 0, "character": 0}},
+    )
+    if "error" in unsupported or unsupported.get("result") is not None:
+        raise AssertionError(f"unsupported feature should answer null: {unsupported}")
+
+    client.notify("unknown/notification", {})
+    ping = client.request("$/ping", {})
+    if ping.get("result", {}).get("status") != "ok":
+        raise AssertionError(f"server stopped answering after an unknown notification: {ping}")
 
     shutdown = client.request("shutdown")
     if shutdown.get("result") is not None:
@@ -147,6 +170,7 @@ def lifecycle(exe: str) -> int:
     if code != 0:
         raise AssertionError(f"exit code is {code}, expected 0")
     print("lifecycle: OK")
+    print("ping: OK")
     return 0