feat: Add option to select GAE nodejs version (#70)

README.md

@@ -37,6 +37,7 @@ Following options are available
 - `useCloudLogging`: Enable or disable [Google Cloud Logging](https://cloud.google.com/logging/docs/overview). When enabled, `console.log`, `console.error` and so on show up with more metadata in Cloud Logging dashboard, and log messages are bundled by request trace id's. Enabled by default.
 - `external`: Node modules that the esbuild step should mark as external.
 - `dependencies`: Node modules that should be added to `package.json` file in the build step. These modules will be fetched when the application is deployed.
+- `nodejsRuntime`: Node version to use in appengine runtime. See available runtimes [here](https://cloud.google.com/appengine/docs/standard/nodejs/runtime). Defaults to `16`
 
 The generated `app.yaml` file can be customized by adding a file named `app.yaml` in the root of the project. The adapter will merge this file with the generated `app.yaml` file, enabling for example custom machine types, added routes or any other [app.yaml configuration](https://cloud.google.com/appengine/docs/standard/reference/app-yaml?tab=node.js)
 

index.d.ts

@@ -16,6 +16,12 @@ type AdapterOptions = {
   external?: string[];
   /** Dependencies to be added in package.json */
   dependencies?: Record<string, string>;
+  /**
+   * Nodejs version to target, defaults to 16
+   * Available runtimes can be seen here:
+   * https://cloud.google.com/appengine/docs/standard/nodejs/runtime
+   */
+  nodejsRuntime?: number;
 };
 
 export default function plugin(options?: AdapterOptions): Adapter;

index.js

@@ -8,7 +8,7 @@ const files = fileURLToPath(new URL('files', import.meta.url));
 
 /** @type {import('.').default} **/
 export default function entrypoint(options = {}) {
-  const {out = 'build', external = [], useCloudLogging = true, dependencies = {}} = options;
+  const {out = 'build', external = [], useCloudLogging = true, dependencies = {}, nodejsRuntime = 16} = options;
 
   return {
     name: 'svelte-adapter-appengine',
@@ -50,7 +50,7 @@ export default function entrypoint(options = {}) {
       await esbuild.build({
         entryPoints: [`${temporary}/entry.js`],
         outfile: `${out}/index.js`,
-        target: 'node16',
+        target: `node${nodejsRuntime}`,
         bundle: true,
         platform: 'node',
         format: 'cjs',
@@ -139,7 +139,7 @@ export default function entrypoint(options = {}) {
         join(out, 'app.yaml'),
         YAML.stringify({
           ...yaml,
-          runtime: 'nodejs16',
+          runtime: `nodejs${nodejsRuntime}`,
           entrypoint: 'node index.js',
           // eslint-disable-next-line camelcase
           default_expiration: '0h',