Node.js standalone mode + support for astro preview (#5056)

* wip

* Deprecate buildConfig and move to config.build

* Implement the standalone server

* Stay backwards compat

* Add changesets

* correctly merge URLs

* Get config earlier

* update node tests

* Return the preview server

* update remaining tests

* swap usage and config ordering

* Update packages/astro/src/@types/astro.ts

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/metal-pumas-walk.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/metal-pumas-walk.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/stupid-points-refuse.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Update .changeset/stupid-points-refuse.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Link to build.server config

Co-authored-by: Fred K. Schott <fkschott@gmail.com>
Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

2 files changed, 42 insertions, 14 deletions

diff --git a/packages/integrations/vercel/src/edge/adapter.ts b/packages/integrations/vercel/src/edge/adapter.ts
index 971aa8eae..ecd13e1f8 100644
--- a/packages/integrations/vercel/src/edge/adapter.ts
+++ b/packages/integrations/vercel/src/edge/adapter.ts
@@ -17,16 +17,35 @@ export default function vercelEdge(): AstroIntegration {
 	let _config: AstroConfig;
 	let functionFolder: URL;
 	let serverEntry: string;
+	let needsBuildConfig = false;
 
 	return {
 		name: PACKAGE_NAME,
 		hooks: {
-			'astro:config:setup': ({ config }) => {
-				config.outDir = getVercelOutput(config.root);
+			'astro:config:setup': ({ config, updateConfig }) => {
+				needsBuildConfig = !config.build.client;
+				const outDir = getVercelOutput(config.root);
+				updateConfig({
+					outDir,
+					build: {
+						serverEntry: 'entry.mjs',
+						client: new URL('./static/', outDir),
+						server: new URL('./functions/render.func/', config.outDir),
+					}
+				});
 			},
 			'astro:config:done': ({ setAdapter, config }) => {
 				setAdapter(getAdapter());
 				_config = config;
+				serverEntry = config.build.serverEntry;
+				functionFolder = config.build.server;
+			},
+			'astro:build:start': ({ buildConfig }) => {
+				if(needsBuildConfig) {
+					buildConfig.client = new URL('./static/', _config.outDir);
+					serverEntry = buildConfig.serverEntry = 'entry.mjs';
+					functionFolder = buildConfig.server = new URL('./functions/render.func/', _config.outDir);
+				}
 			},
 			'astro:build:setup': ({ vite, target }) => {
 				if (target === 'server') {
@@ -49,11 +68,6 @@ export default function vercelEdge(): AstroIntegration {
 					};
 				}
 			},
-			'astro:build:start': async ({ buildConfig }) => {
-				buildConfig.serverEntry = serverEntry = 'entry.mjs';
-				buildConfig.client = new URL('./static/', _config.outDir);
-				buildConfig.server = functionFolder = new URL('./functions/render.func/', _config.outDir);
-			},
 			'astro:build:done': async ({ routes }) => {
 				// Edge function config
 				// https://vercel.com/docs/build-output-api/v3#vercel-primitives/edge-functions/configuration
diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index f5ae4e8cb..dfc0367ae 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -19,16 +19,29 @@ export default function vercelEdge(): AstroIntegration {
 	let buildTempFolder: URL;
 	let functionFolder: URL;
 	let serverEntry: string;
+	let needsBuildConfig = false;
 
 	return {
 		name: PACKAGE_NAME,
 		hooks: {
-			'astro:config:setup': ({ config }) => {
-				config.outDir = getVercelOutput(config.root);
+			'astro:config:setup': ({ config, updateConfig }) => {
+				needsBuildConfig = !config.build.client;
+				const outDir = getVercelOutput(config.root);
+				updateConfig({
+					outDir,
+					build: {
+						serverEntry: 'entry.js',
+						client: new URL('./static/', outDir),
+						server: new URL('./dist/', config.root),
+					}
+				});
 			},
 			'astro:config:done': ({ setAdapter, config }) => {
 				setAdapter(getAdapter());
 				_config = config;
+				buildTempFolder = config.build.server;
+				functionFolder = new URL('./functions/render.func/', config.outDir);
+				serverEntry = config.build.serverEntry;
 
 				if (config.output === 'static') {
 					throw new Error(`
@@ -37,11 +50,12 @@ export default function vercelEdge(): AstroIntegration {
 	`);
 				}
 			},
-			'astro:build:start': async ({ buildConfig }) => {
-				buildConfig.serverEntry = serverEntry = 'entry.js';
-				buildConfig.client = new URL('./static/', _config.outDir);
-				buildConfig.server = buildTempFolder = new URL('./dist/', _config.root);
-				functionFolder = new URL('./functions/render.func/', _config.outDir);
+			'astro:build:start': ({ buildConfig }) => {
+				if(needsBuildConfig) {
+					buildConfig.client = new URL('./static/', _config.outDir);
+					buildTempFolder = buildConfig.server = new URL('./dist/', _config.root);
+					serverEntry = buildConfig.serverEntry = 'entry.js';
+				}
 			},
 			'astro:build:done': async ({ routes }) => {
 				// Copy necessary files (e.g. node_modules/)