feat: adapter-static throws buildtime error when !config.kit.prerender.default && !adapter.fallback (#5562)

* feat: adapter-static errors with incorrect config

* changeset

* fix: Update caught incorrectly configured test project

* rename disabled test to fallback

* Update packages/adapter-static/index.js

* lockfile

Co-authored-by: Rich Harris <[email protected]>

Author: elliott-with-the-longest-name-on-github

.changeset/eleven-buckets-deny.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-static': patch
+---
+
+[breaking] Throws when correctly configured to run as a static site of a SPA

packages/adapter-static/index.js

@@ -14,8 +14,8 @@ export default function (options) {
 
 		async adapt(builder) {
 			if (!options?.fallback && !builder.config.kit.prerender.default) {
-				builder.log.warn(
-					'You should set `config.kit.prerender.default` to `true` if no fallback is specified'
+				throw Error(
+					'adapter-static requires `config.kit.prerender.default` to be `true` unless you set the `fallback: true` option to create a single-page app. See https://github.com/sveltejs/kit/tree/master/packages/adapter-static#spa-mode for more information'
 				);
 			}
 

packages/kit/test/prerendering/disabled/package.json renamed to packages/kit/test/prerendering/fallback/package.json

@@ -3,7 +3,7 @@ import adapter from '../../../../adapter-static/index.js';
 /** @type {import('@sveltejs/kit').Config} */
 const config = {
 	kit: {
-		adapter: adapter(),
+		adapter: adapter({ fallback: '200.html' }),
 
 		prerender: {
 			enabled: false