refactor(server): use Bun.Build.CompileTarget and derive host target instead of manual map

apps/server/compile.ts

@@ -4,24 +4,15 @@ import { parseArgs } from 'node:util'
 const ENTRYPOINT = '.output/server/index.mjs'
 const OUTDIR = 'out'
 
-const TARGETS = {
-  'bun-windows-x64': true,
-  'bun-darwin-arm64': true,
-  'bun-linux-x64': true,
-  'bun-linux-arm64': true,
-} as const
+const SUPPORTED_TARGETS: readonly Bun.Build.CompileTarget[] = [
+  'bun-windows-x64',
+  'bun-darwin-arm64',
+  'bun-linux-x64',
+  'bun-linux-arm64',
+]
 
-type Target = keyof typeof TARGETS
-
-const isTarget = (value: unknown): value is Target =>
-  typeof value === 'string' && value in TARGETS
-
-const HOST_MAP: Record<string, Target> = {
-  'win32-x64': 'bun-windows-x64',
-  'darwin-arm64': 'bun-darwin-arm64',
-  'linux-x64': 'bun-linux-x64',
-  'linux-arm64': 'bun-linux-arm64',
-}
+const isSupportedTarget = (value: string): value is Bun.Build.CompileTarget =>
+  (SUPPORTED_TARGETS as readonly string[]).includes(value)
 
 const { values } = parseArgs({
   options: { target: { type: 'string' } },
@@ -29,22 +20,22 @@ const { values } = parseArgs({
   allowPositionals: false,
 })
 
-const resolveTarget = (): Target => {
+const resolveTarget = (): Bun.Build.CompileTarget => {
   if (values.target !== undefined) {
-    if (!isTarget(values.target)) {
+    if (!isSupportedTarget(values.target)) {
       throw new Error(
-        `Invalid target: ${values.target}\nAllowed: ${Object.keys(TARGETS).join(', ')}`,
+        `Invalid target: ${values.target}\nAllowed: ${SUPPORTED_TARGETS.join(', ')}`,
       )
     }
     return values.target
   }
 
-  const key = `${process.platform}-${process.arch}`
-  const target = HOST_MAP[key]
-  if (!target) {
-    throw new Error(`Unsupported host: ${key}`)
+  const os = process.platform === 'win32' ? 'windows' : process.platform
+  const candidate = `bun-${os}-${process.arch}`
+  if (!isSupportedTarget(candidate)) {
+    throw new Error(`Unsupported host: ${process.platform}-${process.arch}`)
   }
-  return target
+  return candidate
 }
 
 const main = async () => {