fix: ensure define overrides import.meta in build

packages/vite/src/node/plugins/define.ts

@@ -39,6 +39,7 @@ export function definePlugin(config: ResolvedConfig): Plugin {
   // during dev, import.meta properties are handled by importAnalysis plugin.
   // ignore replace import.meta.env in lib build
   const importMetaKeys: Record<string, string> = {}
+  const importMetaFallbackKeys: Record<string, string> = {}
   if (isBuild) {
     const env: Record<string, any> = {
       ...config.env,
@@ -47,7 +48,7 @@ export function definePlugin(config: ResolvedConfig): Plugin {
     for (const key in env) {
       importMetaKeys[`import.meta.env.${key}`] = JSON.stringify(env[key])
     }
-    Object.assign(importMetaKeys, {
+    Object.assign(importMetaFallbackKeys, {
       'import.meta.env.': `({}).`,
       'import.meta.env': JSON.stringify(config.env),
       'import.meta.hot': `false`
@@ -61,8 +62,9 @@ export function definePlugin(config: ResolvedConfig): Plugin {
 
     const replacements: Record<string, string> = {
       ...(replaceProcessEnv ? processNodeEnv : {}),
-      ...userDefine,
       ...importMetaKeys,
+      ...userDefine,
+      ...importMetaFallbackKeys,
       ...(replaceProcessEnv ? processEnv : {})
     }
 

playground/env/.env

@@ -1,3 +1,4 @@
 VITE_CUSTOM_ENV_VARIABLE=1
 CUSTOM_PREFIX_ENV_VARIABLE=1
-VITE_EFFECTIVE_MODE_FILE_NAME=.env
+VITE_EFFECTIVE_MODE_FILE_NAME=.env
+VITE_BOOL=true

playground/env/__tests__/env.spec.ts

@@ -36,6 +36,10 @@ test('inline variables', async () => {
   )
 })
 
+test('bool', async () => {
+  expect(await page.textContent('.bool')).toBe('boolean')
+})
+
 test('NODE_ENV', async () => {
   expect(await page.textContent('.node-env')).toBe(process.env.NODE_ENV)
 })

playground/env/index.html

@@ -12,6 +12,7 @@ <h1>Environment Variables</h1>
   import.meta.env.VITE_EFFECTIVE_MODE_FILE_NAME: <code class="mode-file"></code>
 </p>
 <p>import.meta.env.VITE_INLINE: <code class="inline"></code></p>
+<p>typeof import.meta.env.VITE_BOOL: <code class="bool"></code></p>
 <p>process.env.NODE_ENV: <code class="node-env"></code></p>
 <p>import.meta.env: <span class="pre env-object"></span></p>
 <p>import.meta.url: <span class="pre url"></span></p>
@@ -25,6 +26,7 @@ <h1>Environment Variables</h1>
   text('.custom-prefix', import.meta.env.CUSTOM_PREFIX_ENV_VARIABLE)
   text('.mode-file', import.meta.env.VITE_EFFECTIVE_MODE_FILE_NAME)
   text('.inline', import.meta.env.VITE_INLINE)
+  text('.bool', typeof import.meta.env.VITE_BOOL)
   text('.node-env', process.env.NODE_ENV)
   text('.env-object', JSON.stringify(import.meta.env, null, 2))
 

playground/env/vite.config.js

@@ -5,5 +5,8 @@ module.exports = defineConfig({
   envPrefix: ['VITE_', 'CUSTOM_PREFIX_'],
   build: {
     outDir: 'dist/env'
+  },
+  define: {
+    'import.meta.env.VITE_BOOL': true
   }
 })