Allow Actions with static output when an adapter is configured

.changeset/actions-static-with-adapter.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes Actions failing with `ActionsWithoutServerOutputError` when using `output: 'static'` with an adapter

packages/astro/src/actions/integration.ts

@@ -41,7 +41,7 @@ export default function astroIntegrationActionsRouteHandler({
 				});
 			},
 			'astro:routes:resolved': ({ routes }) => {
-				if (!hasNonPrerenderedRoute(routes)) {
+				if (!settings.config.adapter && !hasNonPrerenderedRoute(routes)) {
 					const error = new AstroError(ActionsWithoutServerOutputError);
 					error.stack = undefined;
 					throw error;

packages/astro/test/actions.test.js

@@ -476,6 +476,25 @@ describe('Astro Actions in static mode with prerender = false routes', () => {
 	});
 });
 
+it('Works with adapter and all pages prerendered', async () => {
+	const fixture = await loadFixture({
+		root: './fixtures/actions/',
+		output: 'static',
+		adapter: testAdapter(),
+	});
+	const devServer = await fixture.startDevServer();
+	const res = await fixture.fetch('/_actions/subscribe', {
+		method: 'POST',
+		headers: {
+			'Content-Type': 'application/json',
+		},
+		body: JSON.stringify({ channel: 'bholmesdev' }),
+	});
+
+	assert.equal(res.ok, true);
+	await devServer.stop();
+});
+
 it('Base path should be used', async () => {
 	const fixture = await loadFixture({
 		root: './fixtures/actions/',