Change 404 to 301 for omitting base for items in public (#5342)

2 files changed, 11 insertions, 6 deletions

diff --git a/packages/astro/src/vite-plugin-astro-server/base.ts b/packages/astro/src/vite-plugin-astro-server/base.ts
index 4fad19a2b..e65c948c2 100644
--- a/packages/astro/src/vite-plugin-astro-server/base.ts
+++ b/packages/astro/src/vite-plugin-astro-server/base.ts
@@ -2,7 +2,7 @@ import type * as vite from 'vite';
 import type { AstroSettings } from '../@types/astro';
 
 import * as fs from 'fs';
-import { LogOptions } from '../core/logger/core.js';
+import { LogOptions, warn } from '../core/logger/core.js';
 import notFoundTemplate, { subpathNotUsedTemplate } from '../template/4xx.js';
 import { log404 } from './common.js';
 import { writeHtmlResponse } from './response.js';
@@ -13,7 +13,8 @@ export function baseMiddleware(
 ): vite.Connect.NextHandleFunction {
 	const { config } = settings;
 	const site = config.site ? new URL(config.base, config.site) : undefined;
-	const devRoot = site ? site.pathname : new URL(config.base, 'http://localhost').pathname;
+	const devRootURL = new URL(config.base, 'http://localhost');
+	const devRoot = site ? site.pathname : devRootURL.pathname;
 
 	return function devBaseMiddleware(req, res, next) {
 		const url = req.url!;
@@ -46,9 +47,12 @@ export function baseMiddleware(
 		const publicPath = new URL('.' + req.url, config.publicDir);
 		fs.stat(publicPath, (_err, stats) => {
 			if (stats) {
-				log404(logging, pathname);
-				const html = subpathNotUsedTemplate(devRoot, pathname);
-				return writeHtmlResponse(res, 404, html);
+				const expectedLocation = new URL('.' + url, devRootURL).pathname;
+				warn(logging, 'dev', `Requests for items in your public folder must also include your base. ${url} should be ${expectedLocation}. Omitting the base will break in production.`);
+				res.writeHead(301, {
+					'Location': expectedLocation
+				});
+				res.end();
 			} else {
 				next();
 			}
diff --git a/packages/astro/test/units/dev/dev.test.js b/packages/astro/test/units/dev/dev.test.js
index ad3fba650..eddc14c5d 100644
--- a/packages/astro/test/units/dev/dev.test.js
+++ b/packages/astro/test/units/dev/dev.test.js
@@ -187,7 +187,8 @@ describe('dev container', () => {
 				container.handle(r.req, r.res);
 				await r.done;
 
-				expect(r.res.statusCode).to.equal(404);
+				expect(r.res.statusCode).to.equal(301);
+				expect(r.res.getHeader('location')).to.equal('/sub/test.txt');
 			}
 		);
 	});