feat(firebase): support renaming exported server function

docs/content/2.deploy/providers/firebase.md

@@ -244,3 +244,33 @@ You may be warned that other cloud functions will be deleted when you deploy you
 ```bash
 firebase deploy --only functions:server,hosting
 ```
+
+## Advanced
+
+### Renaming Function
+
+When deploying multiple apps within the same Firebase project, you must give your server a unique name in order to avoid overwriting
+your functions.
+
+You can specify a new name for the deployed Firebase function in your configuration:
+
+::code-group
+```ts [nitro.config.ts]
+import { defineNitroConfig } from 'nitropack/config'
+
+export default defineNitroConfig({
+  firebase: {
+    serverFunctionName: "<new_function_name>"
+  }
+})
+```
+```ts [nuxt.config.ts]
+export default defineNuxtConfig({
+  nitro: {
+    firebase: {
+      serverFunctionName: "<new_function_name>"
+    }
+  }
+})
+```
+::

src/presets/firebase.ts

@@ -1,6 +1,7 @@
 import { existsSync } from "node:fs";
-import { join, relative } from "pathe";
+import { join, relative, basename } from "pathe";
 import { readPackageJSON, writePackageJSON } from "pkg-types";
+import type { Plugin } from "rollup";
 import { writeFile } from "../utils";
 import { defineNitroPreset } from "../preset";
 import type { Nitro } from "../types";
@@ -19,7 +20,7 @@ export const firebase = defineNitroPreset({
       await writeFirebaseConfig(nitro);
       await updatePackageJSON(nitro);
     },
-    "rollup:before": (nitro) => {
+    "rollup:before": (nitro, rollupConfig) => {
       const _gen = nitro.options.firebase?.gen as unknown;
       if (!_gen || _gen === "default") {
         nitro.logger.warn(
@@ -30,6 +31,22 @@ export const firebase = defineNitroPreset({
       }
       nitro.options.appConfig.nitro = nitro.options.appConfig.nitro || {};
       nitro.options.appConfig.nitro.firebase = nitro.options.firebase;
+
+      // Replace __firebaseServerFunctionName__ to actual name in entries
+      (rollupConfig.plugins as Plugin[]).unshift({
+        name: "nitro:firebase",
+        transform: (code, id) => {
+          if (basename(id).startsWith("firebase-gen-")) {
+            return {
+              code: code.replace(
+                /__firebaseServerFunctionName__/g,
+                nitro.options.firebase?.serverFunctionName || "server"
+              ),
+              map: null,
+            };
+          }
+        },
+      } satisfies Plugin);
     },
   },
 });

src/runtime/entries/firebase-gen-1.ts

@@ -6,7 +6,7 @@ import { useAppConfig } from "#internal/nitro";
 
 const firebaseConfig = useAppConfig().nitro.firebase;
 
-export const server = functions
+export const __firebaseServerFunctionName__ = functions
   .region(firebaseConfig.region ?? functions.RESET_VALUE)
   .runWith(firebaseConfig.runtimeOptions ?? functions.RESET_VALUE)
   .https.onRequest(toNodeListener(nitroApp.h3App));

src/runtime/entries/firebase-gen-2.ts

@@ -6,7 +6,7 @@ import { useAppConfig } from "#internal/nitro";
 
 const firebaseConfig = useAppConfig().nitro.firebase;
 
-export const server = onRequest(
+export const __firebaseServerFunctionName__ = onRequest(
   {
     // Must be set to public to allow all public requests by default
     invoker: "public",

src/runtime/entries/firebase-gen-default.ts

@@ -1,2 +1,2 @@
-// we need this file to detect if the user is passing a `gen` property
-export { server } from "./firebase-gen-1";
+// We need this file to detect if the user is not passing a `gen` property
+export { __firebaseServerFunctionName__ } from "./firebase-gen-1";

src/types/presets.ts

@@ -63,6 +63,13 @@ interface FirebaseOptionsBase {
    * @see https://cloud.google.com/functions/docs/concepts/nodejs-runtime
    */
   nodeVersion?: "20" | "18" | "16";
+  /**
+   * When deploying multiple apps within the same Firebase project
+   * you must give your server a unique name in order to avoid overwriting your functions.
+   *
+   * @default "server"
+   */
+  serverFunctionName?: string;
 }
 
 interface FirebaseOptionsGen1 extends FirebaseOptionsBase {