feat(server-functions-plugin): make the manifest output path configurable (#4232)

As part of the devinxi changes, the following hard-coded output
path of the server functions manifest file was changed.

This would have had breaking changes in the user DX for downstream
frameworks building upon the `@tanstack/server-functions-plugin`
package - (i.e. SolidStart).

This change makes the output path of the manifest file for the
`server-functions-plugin` package, configurable.

Author: SeanCassiere

packages/server-functions-plugin/README.md

@@ -8,8 +8,8 @@ Create a new instance of the plugin with the following options:
 
 ```ts
 const TanStackServerFnsPlugin = createTanStackServerFnPlugin({
-  // This is the ID that will be available to look up and import
-  // our server function manifest and resolve its module
+  // This is the ID (virtual module) that will be made available to look up
+  // and import our server function manifest and resolve its modules.
   manifestVirtualImportId: 'tanstack:server-fn-manifest',
   client: {
     getRuntimeCode: () =>
@@ -86,5 +86,5 @@ export const handler = async (req: Request) => {
   const args = await req.json()
 
   return await fnModule(...args)
-
+}
 ```

packages/server-functions-plugin/src/index.ts

@@ -22,15 +22,28 @@ declare global {
 }
 
 export type ServerFnPluginOpts = {
+  /**
+   * The virtual import ID that will be used to import the server function manifest.
+   * This virtual import ID will be used in the server build to import the manifest
+   * and its modules.
+   */
   manifestVirtualImportId: string
+  /**
+   * The path to the manifest file that will be created during the build process.
+   * This file will be used to import the modules for the server functions in your
+   * server handler.
+   *
+   * @default 'node_modules/.tanstack-start/server-functions-manifest.json'
+   */
+  manifestOutputFilename?: string
   client: ServerFnPluginEnvOpts
   ssr: ServerFnPluginEnvOpts
   server: ServerFnPluginEnvOpts
   importer?: (fn: DirectiveFn) => Promise<any>
 }
 
-const manifestFilename =
-  '.tanstack-start/build/server/server-functions-manifest.json'
+const defaultManifestFilename =
+  'node_modules/.tanstack-start/server-functions-manifest.json'
 
 export type ServerFnPluginEnvOpts = {
   getRuntimeCode: () => string
@@ -71,6 +84,9 @@ export function createTanStackServerFnPlugin(opts: ServerFnPluginOpts): {
     )
   }
 
+  const manifestFilename =
+    opts.manifestOutputFilename || defaultManifestFilename
+
   const directive = 'use server'
   const directiveLabel = 'Server Function'
 
@@ -201,7 +217,20 @@ export function createTanStackServerFnPlugin(opts: ServerFnPluginOpts): {
 }
 
 export interface TanStackServerFnPluginEnvOpts {
+  /**
+   * The virtual import ID that will be used to import the server function manifest.
+   * This virtual import ID will be used in the server build to import the manifest
+   * and its modules.
+   */
   manifestVirtualImportId: string
+  /**
+   * The path to the manifest file that will be created during the build process.
+   * This file will be used to import the modules for the server functions in your
+   * server handler.
+   *
+   * @default 'node_modules/.tanstack-start/server-functions-manifest.json'
+   */
+  manifestOutputFilename?: string
   client: {
     envName?: string
     getRuntimeCode: () => string
@@ -259,6 +288,9 @@ export function TanStackServerFnPluginEnv(
     )
   }
 
+  const manifestFilename =
+    opts.manifestOutputFilename || defaultManifestFilename
+
   const directive = 'use server'
   const directiveLabel = 'Server Function'
 

packages/start-plugin-core/src/plugin.ts

@@ -167,6 +167,8 @@ export function TanStackStartVitePluginCore(
       // This is the ID that will be available to look up and import
       // our server function manifest and resolve its module
       manifestVirtualImportId: 'tanstack-start-server-fn-manifest:v',
+      manifestOutputFilename:
+        '.tanstack-start/build/server/server-functions-manifest.json',
       client: {
         getRuntimeCode: () =>
           `import { createClientRpc } from '@tanstack/${opts.framework}-start/server-functions-client'`,