From e40c93fc80af97fcb9455bfb0affca77b27a56a6 Mon Sep 17 00:00:00 2001
From: Evan Reichard <evan@reichard.io>
Date: Mon, 4 May 2026 07:41:39 -0400
Subject: [PATCH] feat(server): add diagnosticsOnly flag for lint-only servers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add diagnosticsOnly?: boolean to ServerConfig. When set, the server is
excluded from pickServer() (hover/definition/references/completion/
documentSymbol) but still included in pickDiagnosticServers() for
lsp_diagnostics and auto-check.

Mark oxlint as diagnosticsOnly: true — it now contributes diagnostics
alongside typescript-language-server without interfering with navigation
or completion tools.
---
 server.ts    | 1 +
 src/root.ts  | 4 ++--
 src/types.ts | 4 ++++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/server.ts b/server.ts
index 9c94c44..b6e78b7 100644
--- a/server.ts
+++ b/server.ts
@@ -64,5 +64,6 @@ export const servers: ServerConfig[] = [
     args: ["--lsp"],
     rootMarkers: [".oxlintrc.json", "oxlint.config.json"],
     languageId: "typescript",
+    diagnosticsOnly: true,
   },
 ];
diff --git a/src/root.ts b/src/root.ts
index ae5eb74..09e8edd 100644
--- a/src/root.ts
+++ b/src/root.ts
@@ -30,10 +30,10 @@ export function isServerAvailable(server: ServerConfig): boolean {
 }
 
 // Pick Server By File Extension - match[] entries are matched against the
-// file's extension (no dot). First available server in the registry wins.
+// file's extension (no dot). First available, non-diagnosticsOnly server wins.
 export function pickServer(filePath: string): ServerConfig {
   const ext = path.extname(filePath).replace(/^\./, "");
-  const hit = servers.find((s) => s.match.includes(ext) && isServerAvailable(s));
+  const hit = servers.find((s) => s.match.includes(ext) && !s.diagnosticsOnly && isServerAvailable(s));
   if (!hit) {
     throw new UnsupportedExtensionError(`.${ext}`);
   }
diff --git a/src/types.ts b/src/types.ts
index 3a529c9..8e1103f 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -34,6 +34,10 @@ export interface ServerConfig {
   // Idle TTL - Daemon keeps one server alive per (id, rootDir) and evicts
   // it after this many ms of inactivity. Defaults to 5 minutes.
   idleTtlMs?: number;
+  // Diagnostics Only - When true, this server is excluded from
+  // hover/definition/references/completion/documentSymbol but included
+  // in lsp_diagnostics and auto-check.
+  diagnosticsOnly?: boolean;
 }
 
 // Supported high-level commands exposed via the CLI. Extend this union