fix(browser): avoid double quotes in config.define

packages/vitest/src/node/plugins/testConfig.ts

@@ -149,13 +149,13 @@ export function TestConfigPlugin(
           // We inject the defines at runtime in non-browser tests,
           // but keep the original behaviour in the browser mode
           const resolvedTestConfig = testConfig as ResolvedConfig
-          if (sharedServer) {
+          if (isBrowserEnabled) {
+            resolvedTestConfig.defines = {}
+          }
+          else if (sharedServer) {
             resolvedTestConfig.defines = sharedServer.defines
             resolvedTestConfig._scriptDefines = sharedServer.scriptDefines
           }
-          else if (isBrowserEnabled) {
-            resolvedTestConfig.defines = config.define || {}
-          }
           else {
             const { defines, scriptDefines } = deleteDefineConfig(config)
             resolvedTestConfig.defines = defines

test/e2e/fixtures/config/browser-define/basic.test.ts

@@ -1,6 +1,9 @@
 import { test, expect } from 'vitest'
 
+declare const FOO: string
+
 test('passes', () => {
+  expect(FOO).toBe('BAR')
   expect(process.env.TEST_PROCESS_ENV).toBe('PROCESS_OK')
   expect(import.meta.env.TEST_META_ENV).toBe('META_OK')
 })

test/e2e/fixtures/config/browser-define/vitest.config.ts

@@ -3,6 +3,7 @@ import { defineConfig } from 'vitest/config'
 
 let config = defineConfig({
   define: {
+    FOO: JSON.stringify('BAR'),
     'process.env.TEST_PROCESS_ENV': JSON.stringify('PROCESS_OK'),
     'import.meta.env.TEST_META_ENV': JSON.stringify('META_OK'),
   },