fix(vitest): allow rewriting process.env.NODE_MODE when using web transform mode (#3957)

Author: sheremet-va

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

@@ -12,7 +12,7 @@ import { GlobalSetupPlugin } from './globalSetup'
 import { CSSEnablerPlugin } from './cssEnabler'
 import { CoverageTransform } from './coverageTransform'
 import { MocksPlugin } from './mocks'
-import { deleteDefineConfig, resolveOptimizerConfig } from './utils'
+import { deleteDefineConfig, hijackVitePluginInject, resolveOptimizerConfig } from './utils'
 import { VitestResolver } from './vitestResolver'
 
 export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest('test')): Promise<VitePlugin[]> {
@@ -158,6 +158,8 @@ export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest('t
             ignored: ['**/*'],
           }
         }
+
+        hijackVitePluginInject(viteConfig)
       },
       async configureServer(server) {
         if (options.watch && process.env.VITE_TEST_WATCHER_DEBUG) {

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

@@ -1,6 +1,6 @@
 import { builtinModules } from 'node:module'
 import { version as viteVersion } from 'vite'
-import type { DepOptimizationOptions, UserConfig as ViteConfig } from 'vite'
+import type { DepOptimizationOptions, ResolvedConfig, UserConfig as ViteConfig } from 'vite'
 import type { DepsOptimizationOptions, InlineConfig } from '../../types'
 
 export function resolveOptimizerConfig(_testOptions: DepsOptimizationOptions | undefined, viteOptions: DepOptimizationOptions | undefined, testConfig: InlineConfig) {
@@ -73,3 +73,14 @@ export function deleteDefineConfig(viteConfig: ViteConfig) {
   }
   return defines
 }
+
+export function hijackVitePluginInject(viteConfig: ResolvedConfig) {
+  // disable replacing `process.env.NODE_ENV` with static string
+  const processEnvPlugin = viteConfig.plugins.find(p => p.name === 'vite:client-inject')
+  if (processEnvPlugin) {
+    const originalTransform = processEnvPlugin.transform as any
+    processEnvPlugin.transform = function transform(code, id, options) {
+      return originalTransform.call(this, code, id, { ...options, ssr: true })
+    }
+  }
+}

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

@@ -10,7 +10,7 @@ import { CSSEnablerPlugin } from './cssEnabler'
 import { SsrReplacerPlugin } from './ssrReplacer'
 import { GlobalSetupPlugin } from './globalSetup'
 import { MocksPlugin } from './mocks'
-import { deleteDefineConfig, resolveOptimizerConfig } from './utils'
+import { deleteDefineConfig, hijackVitePluginInject, resolveOptimizerConfig } from './utils'
 import { VitestResolver } from './vitestResolver'
 
 interface WorkspaceOptions extends UserWorkspaceConfig {
@@ -100,6 +100,9 @@ export function WorkspaceVitestPlugin(project: WorkspaceProject, options: Worksp
 
         return config
       },
+      configResolved(viteConfig) {
+        hijackVitePluginInject(viteConfig)
+      },
       async configureServer(server) {
         try {
           const options = deepMerge(

test/core/test/env-jsdom.test.ts

@@ -0,0 +1,51 @@
+// @vitest-environment jsdom
+
+import { afterAll, expect, test } from 'vitest'
+import { getAuthToken } from '../src/env'
+
+const NODE_ENV = process.env.NODE_ENV
+
+afterAll(() => {
+  process.env.NODE_ENV = NODE_ENV
+})
+
+test('reassigning NODE_ENV', () => {
+  expect(process.env.NODE_ENV).toBeDefined()
+  process.env.NODE_ENV = 'development'
+  expect(process.env.NODE_ENV).toBe('development')
+})
+
+test('reads envs from .env file', () => {
+  expect(import.meta.env.VITE_TEST_ENV).toBe('local')
+})
+
+test('can reassign env locally', () => {
+  import.meta.env.VITEST_ENV = 'TEST'
+  expect(import.meta.env.VITEST_ENV).toBe('TEST')
+})
+
+test('can reassign env everywhere', () => {
+  import.meta.env.AUTH_TOKEN = '123'
+  expect(getAuthToken()).toBe('123')
+  process.env.AUTH_TOKEN = '321'
+  expect(getAuthToken()).toBe('321')
+})
+
+test('can see env in "define"', () => {
+  expect(import.meta.env.TEST_NAME).toBe('hello world')
+  expect(process.env.TEST_NAME).toBe('hello world')
+})
+
+test('has worker env', () => {
+  expect(process.env.VITEST_WORKER_ID).toBeDefined()
+  expect(process.env.VITEST_POOL_ID).toBeDefined()
+})
+
+test('custom env', () => {
+  expect(process.env.CUSTOM_ENV).toBe('foo')
+  expect(import.meta.env.CUSTOM_ENV).toBe('foo')
+})
+
+test('ignores import.meta.env in string literals', () => {
+  expect('import.meta.env').toBe('import' + '.meta.env')
+})