feat(rsc): configure module directive async validation

Author: james-elicx

packages/plugin-rsc/src/plugins/server-function-directives.test.ts

@@ -321,6 +321,18 @@ export async function action() {
     ).rejects.toThrow('non async function')
   })
 
+  it('supports separate async validation for inline and module directives', async () => {
+    const { run } = createHarness([
+      cacheDirective({ rejectNonAsyncModule: false }),
+    ])
+    await expect(
+      run(`"use cache"; export function Page() { return null }`),
+    ).resolves.toBeDefined()
+    await expect(
+      run(`export function getData() { "use cache"; return null }`),
+    ).rejects.toThrow('non async function')
+  })
+
   it.each(['this', 'super', 'arguments'] as const)(
     'rejects %s inside inline directive functions',
     async (expression) => {

packages/plugin-rsc/src/plugins/server-function-directives.ts

@@ -52,6 +52,8 @@ export type ServerFunctionDirective = {
   }) => void
   /** Reject synchronous annotated functions when enabled. */
   rejectNonAsyncFunction?: boolean
+  /** Overrides synchronous-function validation for module-level directives. */
+  rejectNonAsyncModule?: boolean
   /** Returns the runtime expression used to wrap the server function. */
   wrap: (context: ServerFunctionDirectiveContext) => string
   /** Selects which exports a module-level directive wraps and registers. */
@@ -326,6 +328,7 @@ export function vitePluginServerFunctionDirectives(options: Options): Plugin {
             filter: (name, meta) =>
               definition.filterExport?.({ name, id, meta }) ?? true,
             rejectNonAsyncFunction: definition.rejectNonAsyncFunction,
+            rejectNonAsyncModule: definition.rejectNonAsyncModule,
             encode: (value) => {
               needsEncryptionRuntime = true
               return `__vite_rsc_encryption_runtime.encryptActionBoundArgs(${value})`