feat: expose locals to render api and from requests in dev mode (#7385)

Co-authored-by: Emanuele Stoppa <[email protected]>
Co-authored-by: wrapperup <[email protected]>

packages/adapters/node/README.md

@@ -122,6 +122,25 @@ app.use(ssrHandler);
 app.listen({ port: 8080 });
 ```
 
+Additionally, you can also pass in an object to be accessed with `Astro.locals` or in Astro middleware:
+
+```js
+import express from 'express';
+import { handler as ssrHandler } from './dist/server/entry.mjs';
+
+const app = express();
+app.use(express.static('dist/client/'))
+app.use((req, res, next) => {
+  const locals = {
+    title: 'New title'
+  };
+
+  ssrHandler(req, res, next, locals);
+);
+
+app.listen(8080);
+```
+
 Note that middleware mode does not do file serving. You'll need to configure your HTTP framework to do that for you. By default the client assets are written to `./dist/client/`.
 
 ### Standalone

packages/adapters/node/src/nodeMiddleware.ts

@@ -9,14 +9,15 @@ export default function (app: NodeApp, mode: Options['mode']) {
 	return async function (
 		req: IncomingMessage,
 		res: ServerResponse,
-		next?: (err?: unknown) => void
+		next?: (err?: unknown) => void,
+		locals?: object
 	) {
 		try {
 			const route =
 				mode === 'standalone' ? app.match(req, { matchNotFound: true }) : app.match(req);
 			if (route) {
 				try {
-					const response = await app.render(req);
+					const response = await app.render(req, route, locals);
 					await writeWebResponse(app, res, response);
 				} catch (err: unknown) {
 					if (next) {

packages/adapters/node/test/fixtures/locals/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@test/locals",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*",
+    "@astrojs/node": "workspace:*"
+  }
+}

packages/adapters/node/test/fixtures/locals/src/pages/api.js

@@ -0,0 +1,10 @@
+
+export async function post({ locals }) {
+	let out = { ...locals };
+
+	return new Response(JSON.stringify(out), {
+		headers: {
+			'Content-Type': 'application/json'
+		}
+	});
+}

packages/adapters/node/test/fixtures/locals/src/pages/foo.astro

@@ -0,0 +1,4 @@
+---
+const { foo } = Astro.locals;
+---
+<h1>{foo}</h1>

packages/adapters/node/test/locals.test.js

@@ -0,0 +1,53 @@
+import nodejs from '../dist/index.js';
+import { loadFixture, createRequestAndResponse } from './test-utils.js';
+import { expect } from 'chai';
+
+describe('API routes', () => {
+	/** @type {import('./test-utils').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/locals/',
+			output: 'server',
+			adapter: nodejs({ mode: 'middleware' }),
+		});
+		await fixture.build();
+	});
+
+	it('Can render locals in page', async () => {
+		const { handler } = await import('./fixtures/locals/dist/server/entry.mjs');
+		let { req, res, text } = createRequestAndResponse({
+			method: 'POST',
+			url: '/foo',
+		});
+
+		let locals = { foo: 'bar' };
+
+		handler(req, res, () => {}, locals);
+		req.send();
+
+		let html = await text();
+
+		expect(html).to.contain('<h1>bar</h1>');
+	});
+
+	it('Can access locals in API', async () => {
+		const { handler } = await import('./fixtures/locals/dist/server/entry.mjs');
+		let { req, res, done } = createRequestAndResponse({
+			method: 'POST',
+			url: '/api',
+		});
+
+		let locals = { foo: 'bar' };
+
+		handler(req, res, () => {}, locals);
+		req.send();
+
+		let [buffer] = await done;
+
+		let json = JSON.parse(buffer.toString('utf-8'));
+
+		expect(json.foo).to.equal('bar');
+	});
+});