From bace7244e776b3f4c9dd7e3ff1885df668cbcb87 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Sat, 13 Feb 2021 14:47:35 -0500
Subject: [PATCH] fix(plugin-legacy): prevent constant folding for
 import.meta.env.LEGACY

close #1999
---
 packages/playground/legacy/main.js  | 13 ++++++++++---
 packages/plugin-legacy/index.js     |  6 +++---
 packages/plugin-legacy/package.json |  2 +-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/packages/playground/legacy/main.js b/packages/playground/legacy/main.js
index 84409b57793631..631f589eb541d8 100644
--- a/packages/playground/legacy/main.js
+++ b/packages/playground/legacy/main.js
@@ -5,6 +5,13 @@ async function run() {
 
 run()
 
-document.getElementById('env').textContent = `is legacy: ${
-  import.meta.env.LEGACY
-}`
+let isLegacy
+
+// make sure that branching works despite esbuild's constant folding (#1999)
+if (import.meta.env.LEGACY) {
+  if (import.meta.env.LEGACY === true) isLegacy = true
+} else {
+  if (import.meta.env.LEGACY === false) isLegacy = false
+}
+
+document.getElementById('env').textContent = `is legacy: ${isLegacy}`
diff --git a/packages/plugin-legacy/index.js b/packages/plugin-legacy/index.js
index 32f0a48f58ddcf..9d1cfd4acaf72b 100644
--- a/packages/plugin-legacy/index.js
+++ b/packages/plugin-legacy/index.js
@@ -189,7 +189,7 @@ function viteLegacyPlugin(options = {}) {
         }
 
         if (raw.includes(legacyEnvVarMarker)) {
-          const re = new RegExp(`"${legacyEnvVarMarker}"`, 'g')
+          const re = new RegExp(legacyEnvVarMarker, 'g')
           if (config.build.sourcemap) {
             const s = new MagicString(raw)
             let match
@@ -550,8 +550,8 @@ function replaceLegacyEnvBabelPlugin() {
   return ({ types: t }) => ({
     name: 'vite-replace-env-legacy',
     visitor: {
-      StringLiteral(path) {
-        if (path.node.value === legacyEnvVarMarker) {
+      Identifier(path) {
+        if (path.node.name === legacyEnvVarMarker) {
           path.replaceWith(t.booleanLiteral(true))
         }
       }
diff --git a/packages/plugin-legacy/package.json b/packages/plugin-legacy/package.json
index 0dc6d0cc0aea1d..b7cb6cadb599e5 100644
--- a/packages/plugin-legacy/package.json
+++ b/packages/plugin-legacy/package.json
@@ -32,6 +32,6 @@
     "systemjs": "^6.8.3"
   },
   "peerDependencies": {
-    "vite": "^2.0.0-beta.12"
+    "vite": "^2.0.0-beta.70"
   }
 }