From c916db97a9647b20af9cfadbb1e4693ff4384caa Mon Sep 17 00:00:00 2001
From: Romuald Brillout <git@brillout.com>
Date: Sat, 7 May 2022 09:39:06 +0200
Subject: [PATCH] feat: option to disable SPA catch-all

---
 packages/vite/src/node/http.ts         |  8 ++++++++
 packages/vite/src/node/preview.ts      | 19 +++++++++++++++++--
 packages/vite/src/node/server/index.ts |  5 ++++-
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/packages/vite/src/node/http.ts b/packages/vite/src/node/http.ts
index bfc2ddbe32a302..8129f6e3bb5687 100644
--- a/packages/vite/src/node/http.ts
+++ b/packages/vite/src/node/http.ts
@@ -69,6 +69,14 @@ export interface CommonServerOptions {
    * Specify server response headers.
    */
   headers?: HttpServerHeaders
+  /**
+   * Disable SPA catch-all routing.
+   *
+   * By default, Vite's dev/preview server redirects all routes to the root
+   * URL `/`. (In order to enable client-side routed SPAs.) For SSR or MPA apps,
+   * this behavior should be disabled and this option allows you to do so.
+   */
+  disableSPACatchAll?: boolean
 }
 
 /**
diff --git a/packages/vite/src/node/preview.ts b/packages/vite/src/node/preview.ts
index c1670c5d7efa72..6c6d1ec30b2ca4 100644
--- a/packages/vite/src/node/preview.ts
+++ b/packages/vite/src/node/preview.ts
@@ -1,4 +1,5 @@
 import path from 'path'
+import fs from 'fs'
 import sirv from 'sirv'
 import connect from 'connect'
 import compression from './server/middlewares/compression'
@@ -34,7 +35,8 @@ export function resolvePreviewOptions(
     open: preview?.open ?? server.open,
     proxy: preview?.proxy ?? server.proxy,
     cors: preview?.cors ?? server.cors,
-    headers: preview?.headers ?? server.headers
+    headers: preview?.headers ?? server.headers,
+    disableSPACatchAll: preview?.disableSPACatchAll ?? server.disableSPACatchAll
   }
 }
 
@@ -83,16 +85,29 @@ export async function preview(
 
   app.use(compression())
 
+  const { disableSPACatchAll } = config.preview
   const distDir = path.resolve(config.root, config.build.outDir)
   app.use(
     config.base,
     sirv(distDir, {
       etag: true,
       dev: true,
-      single: true
+      single: !disableSPACatchAll
     })
   )
 
+  if (disableSPACatchAll) {
+    app.use(config.base, (_, res, next) => {
+      const file = path.join(distDir, './404.html')
+      if (fs.existsSync(file)) {
+        res.statusCode = 404
+        res.end(fs.readFileSync(file))
+      } else {
+        next()
+      }
+    })
+  }
+
   const options = config.preview
   const hostname = resolveHostname(options.host)
   const port = options.port ?? 4173
diff --git a/packages/vite/src/node/server/index.ts b/packages/vite/src/node/server/index.ts
index b8f1c3330a9b48..a0600cb464241b 100644
--- a/packages/vite/src/node/server/index.ts
+++ b/packages/vite/src/node/server/index.ts
@@ -524,7 +524,10 @@ export async function createServer(
   middlewares.use(serveStaticMiddleware(root, server))
 
   // spa fallback
-  if (!middlewareMode || middlewareMode === 'html') {
+  if (
+    !serverConfig.disableSPACatchAll &&
+    (!middlewareMode || middlewareMode === 'html')
+  ) {
     middlewares.use(spaFallbackMiddleware(root))
   }