fix: move "mergeConfig" into "vitest/config" and add extension to imports in the documentation (#3139)

Author: sheremet-va

docs/advanced/api.md

@@ -40,20 +40,6 @@ const vitest = await createVitest('test', {
 })
 ```
 
-## mergeConfig
-
-You can merge Vitest config using [mergeConfig](https://vitejs.dev/guide/api-javascript.html#mergeconfig) function. It returns a new config object.
-
-```ts
-import { mergeConfig } from 'vitest/node'
-
-function mergeConfig(
-  defaults: Record<string, any>,
-  overrides: Record<string, any>,
-  isRoot = true,
-): Record<string, any>
-```
-
 ## Vitest
 
 Vitest instance requires the current test mode. It can be either:

docs/api/expect.md

@@ -135,7 +135,7 @@ type Awaitable<T> = T | PromiseLike<T>
   For example, having this code you don't care for the return value of `stocks.getInfo` - it maybe a complex object, a string, or anything else. The code will still work.
 
   ```ts
-  import { Stocks } from './stocks'
+  import { Stocks } from './stocks.js'
   const stocks = new Stocks()
   stocks.sync('Bill')
   if (stocks.getInfo('Bill'))
@@ -146,7 +146,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { Stocks } from './stocks'
+  import { Stocks } from './stocks.js'
   const stocks = new Stocks()
 
   test('if we know Bill stock, sell apples to him', () => {
@@ -166,7 +166,7 @@ type Awaitable<T> = T | PromiseLike<T>
   For example, having this code you don't care for the return value of `stocks.stockFailed` - it may return any falsy value, but the code will still work.
 
   ```ts
-  import { Stocks } from './stocks'
+  import { Stocks } from './stocks.js'
   const stocks = new Stocks()
   stocks.sync('Bill')
   if (!stocks.stockFailed('Bill'))
@@ -177,7 +177,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { Stocks } from './stocks'
+  import { Stocks } from './stocks.js'
   const stocks = new Stocks()
 
   test('if Bill stock hasn\'t failed, sell apples to him', () => {
@@ -251,7 +251,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { Stocks } from './stocks'
+  import { Stocks } from './stocks.js'
   const stocks = new Stocks()
 
   test('stocks are instance of Stocks', () => {
@@ -267,7 +267,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { getApples } from './stock'
+  import { getApples } from './stocks.js'
 
   test('have more then 10 apples', () => {
     expect(getApples()).toBeGreaterThan(10)
@@ -282,7 +282,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { getApples } from './stock'
+  import { getApples } from './stocks.js'
 
   test('have 11 apples or more', () => {
     expect(getApples()).toBeGreaterThanOrEqual(11)
@@ -297,7 +297,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { getApples } from './stock'
+  import { getApples } from './stocks.js'
 
   test('have less then 20 apples', () => {
     expect(getApples()).toBeLessThan(20)
@@ -312,7 +312,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { getApples } from './stock'
+  import { getApples } from './stocks.js'
 
   test('have 11 apples or less', () => {
     expect(getApples()).toBeLessThanOrEqual(11)
@@ -386,7 +386,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { getAllFruits } from './stock'
+  import { getAllFruits } from './stocks.js'
 
   test('the fruit list contains orange', () => {
     expect(getAllFruits()).toContain('orange')
@@ -402,7 +402,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { getFruitStock } from './stock'
+  import { getFruitStock } from './stocks.js'
 
   test('apple available', () => {
     expect(getFruitStock()).toContainEqual({ fruit: 'apple', count: 5 })
@@ -1060,7 +1060,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { db } from './db'
+  import { db } from './db.js'
 
   const cbs = []
 
@@ -1113,7 +1113,7 @@ type Awaitable<T> = T | PromiseLike<T>
 
   ```ts
   import { expect, test } from 'vitest'
-  import { generateId } from './generators'
+  import { generateId } from './generators.js'
 
   test('"id" is a number', () => {
     expect({ id: generateId() }).toEqual({ id: expect.any(Number) })

docs/config/index.md

@@ -54,8 +54,7 @@ export default defineConfig({
 When using a separate `vitest.config.js`, you can also extend Vite's options from another config file if needed:
 
 ```ts
-import { mergeConfig } from 'vite'
-import { defineConfig } from 'vitest/config'
+import { defineConfig, mergeConfig } from 'vitest/config'
 import viteConfig from './vite.config'
 
 export default mergeConfig(viteConfig, defineConfig({
@@ -65,6 +64,10 @@ export default mergeConfig(viteConfig, defineConfig({
 }))
 ```
 
+::: warning
+`mergeConfig` helper is availabe in Vitest since v0.30.0. You can import it from `vite` directly, if you use lower version.
+:::
+
 ## Options
 
 :::tip

docs/guide/mocking.md

@@ -171,7 +171,7 @@ The following principles apply
 ```js
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { Client } from 'pg'
-import { failure, success } from './handlers'
+import { failure, success } from './handlers.js'
 
 // handlers
 export function success(data) {}
@@ -385,26 +385,26 @@ vi.spyOn(instance, 'method')
 ```
 
 - Mock exported variables
-```ts
-// some-path.ts
+```js
+// some-path.js
 export const getter = 'variable'
 ```
 ```ts
 // some-path.test.ts
-import * as exports from 'some-path'
+import * as exports from './some-path.js'
 vi.spyOn(exports, 'getter', 'get').mockReturnValue('mocked')
 ```
 
 - Mock exported function
 
 Example with `vi.mock`:
 ```ts
-// ./some-path.ts
+// ./some-path.js
 export function method() {}
 ```
 ```ts
-import { method } from './some-path.ts'
-vi.mock('./some-path.ts', () => ({
+import { method } from './some-path.js'
+vi.mock('./some-path.js', () => ({
   method: vi.fn()
 }))
 ```
@@ -415,7 +415,7 @@ Don't forget that `vi.mock` call is hoisted to top of the file. **Do not** put `
 
 Example with `vi.spyOn`:
 ```ts
-import * as exports from 'some-path'
+import * as exports from './some-path.js'
 vi.spyOn(exports, 'method').mockImplementation(() => {})
 ```
 
@@ -427,8 +427,8 @@ Example with `vi.mock` and prototype:
 export class SomeClass {}
 ```
 ```ts
-import { SomeClass } from 'some-path'
-vi.mock('some-path', () => {
+import { SomeClass } from './some-path.js'
+vi.mock('./some-path.js', () => {
   const SomeClass = vi.fn()
   SomeClass.prototype.someMethod = vi.fn()
   return { SomeClass }
@@ -438,8 +438,8 @@ vi.mock('some-path', () => {
 
 Example with `vi.mock` and return value:
 ```ts
-import { SomeClass } from 'some-path'
-vi.mock('some-path', () => {
+import { SomeClass } from './some-path.js'
+vi.mock('./some-path.js', () => {
   const SomeClass = vi.fn(() => ({
     someMethod: vi.fn()
   }))
@@ -451,7 +451,7 @@ vi.mock('some-path', () => {
 Example with `vi.spyOn`:
 
 ```ts
-import * as exports from 'some-path'
+import * as exports from './some-path.js'
 vi.spyOn(exports, 'SomeClass').mockImplementation(() => {
   // whatever suites you from first two examples
 })
@@ -470,15 +470,15 @@ export function useObject() {
 
 ```ts
 // useObject.js
-import { useObject } from 'some-path'
+import { useObject } from './some-path.js'
 const obj = useObject()
 obj.method()
 ```
 
 ```ts
 // useObject.test.js
-import { useObject } from 'some-path'
-vi.mock('some-path', () => {
+import { useObject } from './some-path.js'
+vi.mock('./some-path.js', () => {
   let _cache
   const useObject = () => {
     if (!_cache) {
@@ -501,9 +501,9 @@ expect(obj.method).toHaveBeenCalled()
 - Mock part of a module
 
 ```ts
-import { mocked, original } from 'some-path'
-vi.mock('some-path', async () => {
-  const mod = await vi.importActual<typeof import('some-path')>('some-path')
+import { mocked, original } from './some-path.js'
+vi.mock('./some-path.js', async () => {
+  const mod = await vi.importActual<typeof import('./some-path.js')>('./some-path.js')
   return {
     ...mod,
     mocked: vi.fn()

packages/vitest/src/config.ts

@@ -6,6 +6,7 @@ export interface UserConfig extends ViteUserConfig {
 
 // will import vitest declare test in module 'vite'
 export { configDefaults, defaultInclude, defaultExclude, coverageConfigDefaults } from './defaults'
+export { mergeConfig } from 'vite'
 
 export type { ConfigEnv }
 export type UserConfigFn = (env: ConfigEnv) => UserConfig | Promise<UserConfig>

packages/vitest/src/node/create.ts

@@ -7,7 +7,6 @@ import { configFiles } from '../constants'
 import { Vitest } from './core'
 import { VitestPlugin } from './plugins'
 
-export { mergeConfig }
 export async function createVitest(mode: VitestRunMode, options: UserConfig, viteOverrides: ViteUserConfig = {}) {
   const ctx = new Vitest(mode)
   const root = resolve(options.root || process.cwd())

packages/vitest/src/node/index.ts

@@ -1,5 +1,5 @@
 export type { Vitest } from './core'
-export { createVitest, mergeConfig } from './create'
+export { createVitest } from './create'
 export { VitestPlugin } from './plugins'
 export { startVitest } from './cli-api'