fix: set mode before running Vite

docs/config/index.md

@@ -6,7 +6,7 @@
 
 - Create `vitest.config.ts`, which will have the higher priority
 - Pass `--config` option to CLI, e.g. `vitest --config ./path/to/vitest.config.ts`
-- Use `process.env.VITEST` to conditionally apply different configuration in `vite.config.ts`
+- Use `process.env.VITEST` or `mode` property on `defineConfig` (will be set to `test` if not overridden) to conditionally apply different configuration in `vite.config.ts`
 
 To configure `vitest` itself, add `test` property in your Vite config. You'll also need to add a reference to Vitest types using a [triple slash command](https://www.typescriptlang.org/docs/handbook/triple-slash-directives.html#-reference-types-) at the top of your config file.
 
@@ -366,3 +366,10 @@ export default defineConfig({
 - **Type:** `PrettyFormatOptions`
 
 Format options for snapshot testing.
+
+### mode
+
+- **Type:** `string`
+- **Default:** `test`
+
+Overrides Vite mode.

docs/guide/index.md

@@ -35,7 +35,7 @@ One of the main advantages of Vitest is its unified configuration with Vite. If
 
 - Create `vitest.config.ts`, which will have the higher priority
 - Pass `--config` option to CLI, e.g. `vitest --config ./path/to/vitest.config.ts`
-- Use `process.env.VITEST` to conditionally apply different configuration in `vite.config.ts`
+- Use `process.env.VITEST` or `mode` property on `defineConfig` (will be set to `test` if not overridden) to conditionally apply different configuration in `vite.config.ts`
 
 To configure `vitest` itself, add `test` property in your Vite config. You'll also need to add a reference to Vitest types using a [triple slash command](https://www.typescriptlang.org/docs/handbook/triple-slash-directives.html#-reference-types-) at the top of your config file.
 
@@ -112,6 +112,7 @@ You can specify additional CLI options like `--port` or `--https`. For a full li
 | `--outputFile <filename>` | Write test results to a file when the `--reporter=json` option is also specified |
 | `--coverage` | Use c8 for coverage |
 | `--run` | Do not watch |
+| `--mode` | Override Vite mode (default: `test`) |
 | `--global` | Inject APIs globally |
 | `--dom` | Mock browser api with happy-dom |
 | `--environment <env>` | Runner environment (default: node) |

packages/vitest/src/node/cli.ts

@@ -25,6 +25,7 @@ cli
   .option('--outputFile <filename>', 'write test results to a file when the --reporter=json option is also specified')
   .option('--coverage', 'use c8 for coverage')
   .option('--run', 'do not watch')
+  .option('--mode', 'override Vite mode (default: test)')
   .option('--globals', 'inject apis globally')
   .option('--global', 'deprecated, use --globals')
   .option('--dom', 'mock browser api with happy-dom')
@@ -76,7 +77,7 @@ async function run(cliFilters: string[], options: CliOptions) {
 async function start(cliFilters: string[], options: CliOptions) {
   process.env.TEST = 'true'
   process.env.VITEST = 'true'
-  process.env.NODE_ENV ??= 'test'
+  process.env.NODE_ENV ??= options.mode || 'test'
 
   if (options.run)
     options.watch = false

packages/vitest/src/node/create.ts

@@ -19,6 +19,8 @@ export async function createVitest(options: UserConfig, viteOverrides: ViteUserC
     root,
     logLevel: 'error',
     configFile: configPath,
+    // this will make "mode" = "test" inside defineConfig
+    mode: options.mode || process.env.NODE_ENV || 'test',
     plugins: await VitestPlugin(options, ctx),
   }
 

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

@@ -28,9 +28,6 @@ export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest())
         preOptions.api = resolveApiConfig(preOptions)
 
         return {
-          // we are setting NODE_ENV when running CLI to 'test',
-          // but it can be overridden
-          mode: viteConfig.mode || process.env.NODE_ENV || 'test',
           clearScreen: false,
           resolve: {
             // by default Vite resolves `module` field, which not always a native ESM module

packages/vitest/src/types/config.ts

@@ -309,6 +309,12 @@ export interface UserConfig extends InlineConfig {
    * Run tests that cover a list of source files
    */
   related?: string[] | string
+
+  /**
+   * Overrides Vite mode
+   * @default 'test'
+   */
+  mode?: string
 }
 
 export interface ResolvedConfig extends Omit<Required<UserConfig>, 'config' | 'filters' | 'coverage' | 'testNamePattern' | 'related' | 'api' | 'reporters'> {

test/core/test/basic.test.ts

@@ -25,6 +25,11 @@ test('JSON', () => {
   assert.deepEqual(JSON.parse(output), input, 'matches original')
 })
 
+test('mode and NODE_ENV is test by default', () => {
+  expect(process.env.NODE_ENV).toBe('test')
+  expect(import.meta.env.MODE).toBe('test')
+})
+
 test('assertion is callable', () => {
   const str = '13'
   expect(str).to.be.a('string')