From 983feb2cdc5180dc46c3f5fc5b99baaa8d6b7078 Mon Sep 17 00:00:00 2001
From: yoho <907415276@qq.com>
Date: Sun, 20 Feb 2022 00:06:03 +0800
Subject: [PATCH] fix: cannot reassign process.env.NODE_ENV in ssr (#6989)

---
 packages/vite/src/node/plugins/define.ts | 39 +++++++++++++++---------
 1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/packages/vite/src/node/plugins/define.ts b/packages/vite/src/node/plugins/define.ts
index f26df9e4d99405..187cacf54ab1c8 100644
--- a/packages/vite/src/node/plugins/define.ts
+++ b/packages/vite/src/node/plugins/define.ts
@@ -42,9 +42,11 @@ export function definePlugin(config: ResolvedConfig): Plugin {
 
   function generatePattern(
     ssr: boolean
-  ): [Record<string, string | undefined>, RegExp] {
+  ): [Record<string, string | undefined>, RegExp | null] {
     const processEnv: Record<string, string> = {}
-    if (!ssr || config.ssr?.target === 'webworker') {
+    const isNeedProcessEnv = !ssr || config.ssr?.target === 'webworker'
+
+    if (isNeedProcessEnv) {
       Object.assign(processEnv, {
         'process.env.': `({}).`,
         'global.process.env.': `({}).`,
@@ -53,24 +55,27 @@ export function definePlugin(config: ResolvedConfig): Plugin {
     }
 
     const replacements: Record<string, string> = {
-      ...processNodeEnv,
+      ...(isNeedProcessEnv ? processNodeEnv : {}),
       ...userDefine,
       ...importMetaKeys,
       ...processEnv
     }
 
-    const pattern = new RegExp(
-      // Do not allow preceding '.', but do allow preceding '...' for spread operations
-      '(?<!(?<!\\.\\.)\\.)\\b(' +
-        Object.keys(replacements)
-          .map((str) => {
-            return str.replace(/[-[\]/{}()*+?.\\^$|]/g, '\\$&')
-          })
-          .join('|') +
-        // prevent trailing assignments
-        ')\\b(?!\\s*?=[^=])',
-      'g'
-    )
+    const replacementsKeys = Object.keys(replacements)
+    const pattern = replacementsKeys.length
+      ? new RegExp(
+          // Do not allow preceding '.', but do allow preceding '...' for spread operations
+          '(?<!(?<!\\.\\.)\\.)\\b(' +
+            replacementsKeys
+              .map((str) => {
+                return str.replace(/[-[\]/{}()*+?.\\^$|]/g, '\\$&')
+              })
+              .join('|') +
+            // prevent trailing assignments
+            ')\\b(?!\\s*?=[^=])',
+          'g'
+        )
+      : null
 
     return [replacements, pattern]
   }
@@ -98,6 +103,10 @@ export function definePlugin(config: ResolvedConfig): Plugin {
 
       const [replacements, pattern] = ssr ? ssrPattern : defaultPattern
 
+      if (!pattern) {
+        return null
+      }
+
       if (ssr && !isBuild) {
         // ssr + dev, simple replace
         return code.replace(pattern, (_, match) => {