feat(vitest): add "provide" option (#6253)

docs/config/index.md

@@ -1003,6 +1003,54 @@ afterEach(() => {
 globalThis.resetBeforeEachTest = true
 ```
 
+### provide <Version>2.1.0</Version> {#provide}
+
+- **Type:** `Partial<ProvidedContext>`
+
+Define values that can be accessed inside your tests using `inject` method.
+
+:::code-group
+```ts [vitest.config.js]
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    provide: {
+      API_KEY: '123',
+    },
+  },
+})
+```
+```ts [my.test.js]
+import { expect, inject, test } from 'vitest'
+
+test('api key is defined', () => {
+  expect(inject('API_KEY')).toBe('123')
+})
+```
+:::
+
+::: warning
+Properties have to be strings and values need to be [serializable](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm#supported_types) because this object will be transferred between different processes.
+:::
+
+::: tip
+If you are using TypeScript, you will need to augment `ProvidedContext` type for type safe access:
+
+```ts
+// vitest.shims.d.ts
+
+declare module 'vitest' {
+  export interface ProvidedContext {
+    API_KEY: string
+  }
+}
+
+// mark this file as a module so augmentation works correctly
+export {}
+```
+:::
+
 ### globalSetup
 
 - **Type:** `string | string[]`
@@ -1018,7 +1066,7 @@ Multiple globalSetup files are possible. setup and teardown are executed sequent
 ::: warning
 Global setup runs only if there is at least one running test. This means that global setup might start running during watch mode after test file is changed (the test file will wait for global setup to finish before running).
 
-Beware that the global setup is running in a different global scope, so your tests don't have access to variables defined here. However, you can pass down serializable data to tests via `provide` method:
+Beware that the global setup is running in a different global scope, so your tests don't have access to variables defined here. However, you can pass down serializable data to tests via [`provide`](#provide) method:
 
 :::code-group
 ```js [globalSetup.js]
@@ -1033,8 +1081,6 @@ export default function setup({ provide }: GlobalSetupContext) {
   provide('wsPort', 3000)
 }
 
-// You can also extend `ProvidedContext` type
-// to have type safe access to `provide/inject` methods:
 declare module 'vitest' {
   export interface ProvidedContext {
     wsPort: number

packages/vitest/src/node/cli/cli-config.ts

@@ -794,6 +794,7 @@ export const cliOptionsConfig: VitestCLIOptions = {
   compare: null,
   outputJson: null,
   json: null,
+  provide: null,
 }
 
 export const benchCliOptionsConfig: Pick<

packages/vitest/src/node/config/resolveConfig.ts

@@ -140,6 +140,8 @@ export function resolveConfig(
     mode,
   } as any as ResolvedConfig
 
+  resolved.provide ??= {}
+
   const inspector = resolved.inspect || resolved.inspectBrk
 
   resolved.inspector = {

packages/vitest/src/node/types/config.ts

@@ -10,7 +10,7 @@ import type {
 } from '../reporters'
 import type { TestSequencerConstructor } from '../sequencers/types'
 import type { ChaiConfig } from '../../integrations/chai/config'
-import type { Arrayable, ErrorWithDiff, ParsedStack } from '../../types/general'
+import type { Arrayable, ErrorWithDiff, ParsedStack, ProvidedContext } from '../../types/general'
 import type { JSDOMOptions } from '../../types/jsdom-options'
 import type { HappyDOMOptions } from '../../types/happy-dom-options'
 import type { EnvironmentOptions } from '../../types/environment'
@@ -731,6 +731,27 @@ export interface InlineConfig {
     waitForDebugger?: boolean
   }
 
+  /**
+   * Define variables that will be returned from `inject` in the test environment.
+   * @example
+   * ```ts
+   * // vitest.config.ts
+   * export default defineConfig({
+   *   test: {
+   *     provide: {
+   *       someKey: 'someValue'
+   *     }
+   *   }
+   * })
+   * ```
+   * ```ts
+   * // test file
+   * import { inject } from 'vitest'
+   * const value = inject('someKey') // 'someValue'
+   * ```
+   */
+  provide?: Partial<ProvidedContext>
+
   /**
    * Configuration options for expect() matches.
    */

packages/vitest/src/node/workspace.ts

@@ -364,6 +364,14 @@ export class WorkspaceProject {
     project.server = ctx.server
     project.runner = ctx.runner
     project.config = ctx.config
+    for (const _providedKey in ctx.config.provide) {
+      const providedKey = _providedKey as keyof ProvidedContext
+      // type is very strict here, so we cast it to any
+      (project.provide as (key: string, value: unknown) => void)(
+        providedKey,
+        ctx.config.provide[providedKey],
+      )
+    }
     project.testProject = new TestProject(project)
     return project
   }
@@ -384,6 +392,15 @@ export class WorkspaceProject {
       server.config,
       this.ctx.logger,
     )
+    for (const _providedKey in this.config.provide) {
+      const providedKey = _providedKey as keyof ProvidedContext
+      // type is very strict here, so we cast it to any
+      (this.provide as (key: string, value: unknown) => void)(
+        providedKey,
+        this.config.provide[providedKey],
+      )
+    }
+
     this.testProject = new TestProject(this)
 
     this.server = server

test/workspaces/globalTest.ts

@@ -7,6 +7,8 @@ declare module 'vitest' {
     globalSetup: boolean
     globalSetupOverriden: boolean
     invalidValue: unknown
+    projectConfigValue: boolean
+    globalConfigValue: boolean
   }
 }
 

test/workspaces/space_3/global-provide.space-3-test.ts

@@ -3,5 +3,7 @@ import { expect, inject, test } from 'vitest'
 test('global setup provides data correctly', () => {
   expect(inject('globalSetup')).toBe(true)
   expect(inject('globalSetupOverriden')).toBe(true)
+  expect(inject('projectConfigValue')).toBe(true)
+  expect(inject('globalConfigValue')).toBe(true)
   expect(inject('invalidValue')).toBe(undefined)
 })

test/workspaces/space_3/vitest.config.ts

@@ -5,5 +5,8 @@ export default defineProject({
     include: ['**/*.space-3-test.ts'],
     environment: 'node',
     globalSetup: './localSetup.ts',
+    provide: {
+      projectConfigValue: true,
+    },
   },
 })

test/workspaces/vitest.config.ts

@@ -16,5 +16,8 @@ export default defineConfig({
       CONFIG_VAR: 'root',
       CONFIG_OVERRIDE: 'root',
     },
+    provide: {
+      globalConfigValue: true,
+    },
   },
 })