fix: unify LSP server PATH resolution between detection and spawn (#2431)

src/tools/lsp/lsp-client-transport.ts

@@ -1,4 +1,5 @@
 import { Readable, Writable } from "node:stream"
+import { delimiter } from "path"
 import {
   createMessageConnection,
   StreamMessageReader,
@@ -7,6 +8,7 @@ import {
 } from "vscode-jsonrpc/node"
 import type { Diagnostic, ResolvedServer } from "./types"
 import { spawnProcess, type UnifiedProcess } from "./lsp-process"
+import { getLspServerAdditionalPathBases } from "./server-path-bases"
 import { log } from "../../shared/logger"
 export class LSPClientTransport {
   protected proc: UnifiedProcess | null = null
@@ -18,12 +20,22 @@ export class LSPClientTransport {
 
   constructor(protected root: string, protected server: ResolvedServer) {}
   async start(): Promise<void> {
+    const env = {
+      ...process.env,
+      ...this.server.env,
+    }
+    const pathValue = process.platform === "win32" ? env.PATH ?? env.Path ?? "" : env.PATH ?? ""
+    const spawnPath = [pathValue, ...getLspServerAdditionalPathBases(this.root)]
+      .filter(Boolean)
+      .join(delimiter)
+    if (process.platform === "win32" && env.Path !== undefined) {
+      env.Path = spawnPath
+    }
+    env.PATH = spawnPath
+
     this.proc = spawnProcess(this.server.command, {
       cwd: this.root,
-      env: {
+      env,
-        ...process.env,
-        ...this.server.env,
-      },
     })
     if (!this.proc) {
       throw new Error(`Failed to spawn LSP server: ${this.server.command.join(" ")}`)

src/tools/lsp/server-installation.ts

@@ -1,7 +1,7 @@
 import { existsSync } from "fs"
-import { join } from "path"
+import { delimiter, join } from "path"
 
-import { getOpenCodeConfigDir, getDataDir } from "../../shared"
+import { getLspServerAdditionalPathBases } from "./server-path-bases"
 
 export function isServerInstalled(command: string[]): boolean {
   if (command.length === 0) return false
@@ -31,8 +31,7 @@ export function isServerInstalled(command: string[]): boolean {
     pathEnv = process.env.Path || ""
   }
 
-  const pathSeparator = isWindows ? ";" : ":"
+  const paths = pathEnv.split(delimiter)
-  const paths = pathEnv.split(pathSeparator)
 
   for (const p of paths) {
     for (const suffix of exts) {
@@ -42,17 +41,7 @@ export function isServerInstalled(command: string[]): boolean {
     }
   }
 
-  const cwd = process.cwd()
+  for (const base of getLspServerAdditionalPathBases(process.cwd())) {
-  const configDir = getOpenCodeConfigDir({ binary: "opencode" })
-  const dataDir = join(getDataDir(), "opencode")
-  const additionalBases = [
-    join(cwd, "node_modules", ".bin"),
-    join(configDir, "bin"),
-    join(configDir, "node_modules", ".bin"),
-    join(dataDir, "bin"),
-  ]
-
-  for (const base of additionalBases) {
     for (const suffix of exts) {
       if (existsSync(join(base, cmd + suffix))) {
         return true

src/tools/lsp/server-path-bases.ts

@@ -0,0 +1,15 @@
+import { join } from "path"
+
+import { getDataDir, getOpenCodeConfigDir } from "../../shared"
+
+export function getLspServerAdditionalPathBases(workingDirectory: string): string[] {
+  const configDir = getOpenCodeConfigDir({ binary: "opencode" })
+  const dataDir = join(getDataDir(), "opencode")
+
+  return [
+    join(workingDirectory, "node_modules", ".bin"),
+    join(configDir, "bin"),
+    join(configDir, "node_modules", ".bin"),
+    join(dataDir, "bin"),
+  ]
+}