From 27b7f90ce2aa9de4290a8422b899d2d718a8c7d7 Mon Sep 17 00:00:00 2001
From: Alec Larson <1925840+aleclarson@users.noreply.github.com>
Date: Mon, 1 Nov 2021 20:50:33 -0400
Subject: [PATCH] fix(server): use `options` argument in caching of
 `transformRequest` calls (#5391)

---
 packages/vite/src/node/server/index.ts        |  4 ++--
 .../vite/src/node/server/transformRequest.ts  | 21 +++++++------------
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/packages/vite/src/node/server/index.ts b/packages/vite/src/node/server/index.ts
index 90f6af4ad00939..3e06ec732e8157 100644
--- a/packages/vite/src/node/server/index.ts
+++ b/packages/vite/src/node/server/index.ts
@@ -324,7 +324,7 @@ export interface ViteDevServer {
   /**
    * @internal
    */
-  _pendingRequests: Record<string, Promise<TransformResult | null> | null>
+  _pendingRequests: Map<string, Promise<TransformResult | null>>
 }
 
 export async function createServer(
@@ -432,7 +432,7 @@ export async function createServer(
     _isRunningOptimizer: false,
     _registerMissingImport: null,
     _pendingReload: null,
-    _pendingRequests: Object.create(null)
+    _pendingRequests: new Map()
   }
 
   server.transformIndexHtml = createDevHtmlTransformFn(server)
diff --git a/packages/vite/src/node/server/transformRequest.ts b/packages/vite/src/node/server/transformRequest.ts
index cf4762cc4b0ff3..4381529dba1c8e 100644
--- a/packages/vite/src/node/server/transformRequest.ts
+++ b/packages/vite/src/node/server/transformRequest.ts
@@ -43,20 +43,15 @@ export function transformRequest(
   server: ViteDevServer,
   options: TransformOptions = {}
 ): Promise<TransformResult | null> {
-  const pending = server._pendingRequests[url]
-  if (pending) {
-    debugTransform(
-      `[reuse pending] for ${prettifyUrl(url, server.config.root)}`
-    )
-    return pending
+  const cacheKey = (options.ssr ? 'ssr:' : options.html ? 'html:' : '') + url
+  let request = server._pendingRequests.get(cacheKey)
+  if (!request) {
+    request = doTransform(url, server, options)
+    server._pendingRequests.set(cacheKey, request)
+    const done = () => server._pendingRequests.delete(cacheKey)
+    request.then(done, done)
   }
-  const result = doTransform(url, server, options)
-  server._pendingRequests[url] = result
-  const onDone = () => {
-    server._pendingRequests[url] = null
-  }
-  result.then(onDone, onDone)
-  return result
+  return request
 }
 
 async function doTransform(