refactor: remove __DEV__

BREAKING CHANGE: `__DEV__` magic flag has been removed

playground/App.vue

@@ -1,8 +1,5 @@
 <template>
   <h1>Vite Playground</h1>
-  <p class="dev">
-    <code>__DEV__: {{ dev }}</code>
-  </p>
   <p class="base">
     <code>process.env.BASE_URL: {{ base }}</code>
   </p>
@@ -57,7 +54,6 @@ import TestDynamicImport from './dynamic-import/TestDynamicImport.vue'
 
 export default {
   data: () => ({
-    dev: __DEV__,
     base: process.env.BASE_URL
   }),
   components: {

src/client/client.ts

@@ -1,3 +1,6 @@
+// replaced by serverPluginHmr when served
+declare const __SW_ENABLED__: boolean
+
 // This file runs in the browser.
 import { HMRRuntime } from 'vue'
 

src/client/env.d.ts

@@ -1,3 +1,3 @@
-declare const __DEV__: boolean
-declare const __BASE__: string
-declare const __SW_ENABLED__: boolean
+declare interface ImportMeta {
+  env: Record<string, string>
+}

src/client/vueJsxCompat.ts

@@ -1,8 +1,6 @@
 import { createVNode, isVNode } from 'vue'
 
-declare const __DEV__: boolean
-
-if (__DEV__) {
+if (import.meta.env.MODE === 'development') {
   console.log(
     `[vue tip] You are using an non-optimized version of Vue 3 JSX, ` +
       `which does not take advantage of Vue 3's runtime fast paths. An improved ` +

src/node/build/index.ts

@@ -259,17 +259,6 @@ export async function build(options: BuildConfig): Promise<BuildResult> {
         },
         sourcemap
       ),
-      // for vite spcific replacements, make sure to only apply them to
-      // non-dependency code to avoid collision (e.g. #224 antd has __DEV__)
-      createReplacePlugin(
-        (id) =>
-          id.startsWith('/vite') ||
-          (!id.includes('node_modules') && /\.(j|t)sx?$/.test(id)),
-        {
-          __DEV__: `false`
-        },
-        sourcemap
-      ),
       // vite:css
       createBuildCssPlugin({
         root,

src/node/server/serverPluginHtml.ts

@@ -23,14 +23,13 @@ export const htmlRewritePlugin: ServerPlugin = ({
   resolver,
   config
 }) => {
-  // inject __DEV__ and process.env.NODE_ENV flags
+  // inject process.env flags
   // since some ESM builds expect these to be replaced by the bundler
   const { env = {}, mode } = config
 
   const devInjectionCode =
     `\n<script type="module">\n` +
     `import "${hmrClientPublicPath}"\n` +
-    `window.__DEV__ = true\n` +
     `window.process = { env: ${JSON.stringify({
       ...env,
       NODE_ENV: mode,

test/test.js

@@ -92,7 +92,6 @@ describe('vite', () => {
     })
 
     test('env variables', async () => {
-      expect(await getText('.dev')).toMatch(`__DEV__: ${!isBuild}`)
       expect(await getText('.base')).toMatch(`process.env.BASE_URL: /`)
       expect(await getText('.node-env')).toMatch(
         `process.env.NODE_ENV: ${isBuild ? 'production' : 'development'}`