Add ttl option to netlify adapter for builders

packages/integrations/netlify/README.md

@@ -13,7 +13,6 @@ Learn how to deploy your Astro site in our [Netlify deployment guide](https://do
 - <strong>[Contributing](#contributing)</strong>
 - <strong>[Changelog](#changelog)</strong>
 
-
 ## Why Astro Netlify
 
 If you're using Astro as a static site builder—its behavior out of the box—you don't need an adapter.
@@ -22,7 +21,6 @@ If you wish to [use server-side rendering (SSR)](https://docs.astro.build/en/gui
 
 [Netlify](https://www.netlify.com/) is a deployment platform that allows you to host your site by connecting directly to your GitHub repository. This adapter enhances the Astro build process to prepare your project for deployment through Netlify.
 
-
 ## Installation
 
 Add the Netlify adapter to enable SSR in your Astro project with the following `astro add` command. This will install the adapter and make the appropriate changes to your `astro.config.mjs` file in one step.
@@ -40,22 +38,22 @@ If you prefer to install the adapter manually instead, complete the following tw
 
 1. Install the Netlify adapter to your project’s dependencies using your preferred package manager. If you’re using npm or aren’t sure, run this in the terminal:
 
-    ```bash
-      npm install @astrojs/netlify
-    ```
+   ```bash
+     npm install @astrojs/netlify
+   ```
 
 1. Add two new lines to your `astro.config.mjs` project configuration file.
 
-    ```js ins={3, 6-7}
-    // astro.config.mjs
-    import { defineConfig } from 'astro/config';
-    import netlify from '@astrojs/netlify/functions';
+   ```js ins={3, 6-7}
+   // astro.config.mjs
+   import { defineConfig } from 'astro/config';
+   import netlify from '@astrojs/netlify/functions';
 
-    export default defineConfig({
-      output: 'server',
-      adapter: netlify(),
-    });
-    ```
+   export default defineConfig({
+     output: 'server',
+     adapter: netlify(),
+   });
+   ```
 
 ### Edge Functions
 
@@ -88,7 +86,6 @@ netlify deploy --build
 
 The [Netlify Blog post on Astro](https://www.netlify.com/blog/how-to-deploy-astro/) and the [Netlify Documentation](https://docs.netlify.com/integrations/frameworks/astro/) provide more information on how to use this integration to deploy to Netlify.
 
-
 ## Configuration
 
 To configure this adapter, pass an object to the `netlify()` function call in `astro.config.mjs` - there's only one possible configuration option:
@@ -105,8 +102,8 @@ import netlify from '@astrojs/netlify/functions';
 export default defineConfig({
   output: 'server',
   adapter: netlify({
-    dist: new URL('./dist/', import.meta.url)
-  })
+    dist: new URL('./dist/', import.meta.url),
+  }),
 });
 ```
 
@@ -129,14 +126,31 @@ import netlify from '@astrojs/netlify/functions';
 export default defineConfig({
   output: 'server',
   adapter: netlify({
-    builders: true
+    builders: true,
   }),
 });
 ```
 
-On-demand Builders are only available with the `@astrojs/netlify/functions` adapter and are not compatible with Edge Functions.
+On-demand Builders optionally let you return a [TTL](https://docs.netlify.com/configure-builds/on-demand-builders/#time-to-live-ttl) (time-to-live) value for the cached page. The astro adapter allows you to set a default TTL value for all pages, or a custom TTL value for specific pages via a function call.
+
+```js
+// astro.config.mjs
+import { defineConfig } from 'astro/config';
+import netlify from '@astrojs/netlify/functions';
 
+export default defineConfig({
+  output: 'server',
+  adapter: netlify({
+    builders: {
+      ttl(event) {
+        return event.path.startsWith('/blog') ? 3600 : undefined;
+      },
+    },
+  }),
+});
+```
 
+On-demand Builders are only available with the `@astrojs/netlify/functions` adapter and are not compatible with Edge Functions.
 
 ### binaryMediaTypes
 
@@ -158,8 +172,8 @@ export function get() {
   return new Response(buffer, {
     status: 200,
     headers: {
-      'content-type': 'image/jpeg'
-    }
+      'content-type': 'image/jpeg',
+    },
   });
 }
 ```
@@ -185,4 +199,3 @@ This package is maintained by Astro's Core team. You're welcome to submit an iss
 See [CHANGELOG.md](CHANGELOG.md) for a history of changes to this integration.
 
 [astro-integration]: https://docs.astro.build/en/guides/integrations-guide/
-

packages/integrations/netlify/src/integration-functions.ts

@@ -1,4 +1,5 @@
 import type { AstroAdapter, AstroConfig, AstroIntegration } from 'astro';
+import type { HandlerEvent } from '@netlify/functions';
 import type { Args } from './netlify-functions.js';
 import { createRedirects } from './shared.js';
 
@@ -13,7 +14,11 @@ export function getAdapter(args: Args = {}): AstroAdapter {
 
 interface NetlifyFunctionsOptions {
 	dist?: URL;
-	builders?: boolean;
+	builders?:
+		| boolean
+		| {
+				ttl?: number | ((event: HandlerEvent) => number | undefined);
+		  };
 	binaryMediaTypes?: string[];
 }
 

packages/integrations/netlify/src/netlify-functions.ts

@@ -1,5 +1,5 @@
 import { polyfill } from '@astrojs/webapi';
-import { builder, Handler } from '@netlify/functions';
+import { builder, Handler, HandlerEvent } from '@netlify/functions';
 import { SSRManifest } from 'astro';
 import { App } from 'astro/app';
 
@@ -8,7 +8,11 @@ polyfill(globalThis, {
 });
 
 export interface Args {
-	builders?: boolean;
+	builders?:
+		| boolean
+		| {
+				ttl?: number | ((event: HandlerEvent) => number | undefined);
+		  };
 	binaryMediaTypes?: string[];
 }
 
@@ -132,6 +136,15 @@ export const createExports = (manifest: SSRManifest, args: Args) => {
 			}
 		}
 
+		if (typeof builders === 'object' && 'ttl' in builders) {
+			const ttlSetting = builders.ttl;
+			if (typeof ttlSetting === 'number') {
+				fnResponse.ttl = ttlSetting;
+			} else if (typeof ttlSetting === 'function') {
+				fnResponse.ttl = ttlSetting(event);
+			}
+		}
+
 		// Apply cookies set via Astro.cookies.set/delete
 		if (app.setCookieHeaders) {
 			const setCookieHeaders = Array.from(app.setCookieHeaders(response));