feat(runner): test context can inject values from the config's provide

docs/guide/test-context.md

@@ -176,9 +176,61 @@ const test = base.extend({
   ],
 })
 
-test('', () => {})
+test('works correctly')
 ```
 
+#### Default fixture
+
+Since Vitest 2.2, you can provide different values in different [projects](/guide/workspace). To enable this feature, pass down `{ injected: true }` to the options. If the key is not specified in the [project configuration](/config/#provide), then the default value will be used.
+
+:::code-group
+```ts [fixtures.test.ts]
+import { test as base } from 'vitest'
+
+const test = base.extend({
+  url: [
+    // default value if "url" is not defined in the config
+    'default',
+    // mark the fixure as "injected" to allow the override
+    { injected: true },
+  ],
+})
+
+test('works correctly', ({ url }) => {
+  // url is "/default" in "project-new"
+  // url is "/full" in "project-full"
+  // url is "/empty" in "project-empty"
+})
+```
+```ts [vitest.workspace.ts]
+import { defineWorkspace } from 'vitest/config'
+
+export default defineWorkspace([
+  {
+    test: {
+      name: 'project-new',
+    },
+  },
+  {
+    test: {
+      name: 'project-full',
+      provide: {
+        url: '/full',
+      },
+    },
+  },
+  {
+    test: {
+      name: 'project-empty',
+      provide: {
+        url: '/empty',
+      },
+    },
+  },
+])
+```
+:::
+
 #### TypeScript
 
 To provide fixture types for all your custom contexts, you can pass the fixtures type as a generic.
@@ -194,7 +246,7 @@ const myTest = test.extend<MyFixtures>({
   archive: []
 })
 
-myTest('', (context) => {
+myTest('types are defined correctly', (context) => {
   expectTypeOf(context.todos).toEqualTypeOf<number[]>()
   expectTypeOf(context.archive).toEqualTypeOf<number[]>()
 })

packages/runner/src/fixture.ts

@@ -5,6 +5,10 @@ import { getFixture } from './map'
 export interface FixtureItem extends FixtureOptions {
   prop: string
   value: any
+  /**
+   * Indicated if the injected value should be preferred over the fixture value
+   */
+  injected?: boolean
   /**
    * Indicates whether the fixture is a function
    */
@@ -17,11 +21,12 @@ export interface FixtureItem extends FixtureOptions {
 
 export function mergeContextFixtures(
   fixtures: Record<string, any>,
-  context: { fixtures?: FixtureItem[] } = {},
+  context: { fixtures?: FixtureItem[] },
+  inject: (key: string) => unknown,
 ): {
     fixtures?: FixtureItem[]
   } {
-  const fixtureOptionKeys = ['auto']
+  const fixtureOptionKeys = ['auto', 'injected']
   const fixtureArray: FixtureItem[] = Object.entries(fixtures).map(
     ([prop, value]) => {
       const fixtureItem = { value } as FixtureItem
@@ -34,7 +39,10 @@ export function mergeContextFixtures(
       ) {
         // fixture with options
         Object.assign(fixtureItem, value[1])
-        fixtureItem.value = value[0]
+        const userValue = value[0]
+        fixtureItem.value = fixtureItem.injected
+          ? (inject(prop) ?? userValue)
+          : userValue
       }
 
       fixtureItem.prop = prop

packages/runner/src/suite.ts

@@ -710,7 +710,11 @@ export function createTaskCollector(
   }
 
   taskFn.extend = function (fixtures: Fixtures<Record<string, any>>) {
-    const _context = mergeContextFixtures(fixtures, context)
+    const _context = mergeContextFixtures(
+      fixtures,
+      context || {},
+      (key: string) => getRunner().injectValue?.(key),
+    )
 
     return createTest(function fn(
       name: string | Function,

packages/runner/src/types/runner.ts

@@ -147,6 +147,10 @@ export interface VitestRunner {
    * Called when test and setup files are imported. Can be called in two situations: when collecting tests and when importing setup files.
    */
   importFile: (filepath: string, source: VitestRunnerImportSource) => unknown
+  /**
+   * Function that is called when the runner attempts to get the value when `test.extend` is used with `{ injected: true }`
+   */
+  injectValue?: (key: string) => unknown
   /**
    * Publicly available configuration.
    */

packages/vitest/src/runtime/runners/test.ts

@@ -16,6 +16,7 @@ import type { VitestExecutor } from '../execute'
 import { getState, GLOBAL_EXPECT, setState } from '@vitest/expect'
 import { getNames, getTestName, getTests } from '@vitest/runner/utils'
 import { createExpect } from '../../integrations/chai/index'
+import { inject } from '../../integrations/inject'
 import { getSnapshotClient } from '../../integrations/snapshot/chai'
 import { vi } from '../../integrations/vi'
 import { rpc } from '../rpc'
@@ -89,6 +90,12 @@ export class VitestTestRunner implements VitestRunner {
     this.cancelRun = true
   }
 
+  injectValue(key: string) {
+    // inject has a very limiting type controlled by ProvidedContext
+    // some tests override it which causes the build to fail
+    return (inject as any)(key)
+  }
+
   async onBeforeRunTask(test: Task) {
     if (this.cancelRun) {
       test.mode = 'skip'

test/workspaces/globalTest.ts

@@ -9,6 +9,8 @@ declare module 'vitest' {
     invalidValue: unknown
     projectConfigValue: boolean
     globalConfigValue: boolean
+
+    providedConfigValue: string
   }
 }
 
@@ -35,8 +37,8 @@ export async function teardown() {
   try {
     assert.ok(results.success)
     assert.equal(results.numTotalTestSuites, 28)
-    assert.equal(results.numTotalTests, 31)
-    assert.equal(results.numPassedTests, 31)
+    assert.equal(results.numTotalTests, 33)
+    assert.equal(results.numPassedTests, 33)
     assert.ok(results.coverageMap)
 
     const shared = results.testResults.filter((r: any) => r.name.includes('space_shared/test.spec.ts'))

test/workspaces/space_shared/test.spec.ts

@@ -4,6 +4,19 @@ declare global {
   const testValue: string
 }
 
+const custom = it.extend({
+  providedConfigValue: ['default value', { injected: true }],
+})
+
+custom('provided config value is injected', ({ providedConfigValue }) => {
+  expect(providedConfigValue).toBe(
+    // happy-dom provides the value in the workspace config
+    expect.getState().environment === 'node'
+      ? 'default value'
+      : 'actual config value',
+  )
+})
+
 it('the same file works with different projects', () => {
   expect(testValue).toBe(expect.getState().environment === 'node' ? 'node' : 'jsdom')
 })

test/workspaces/vitest.workspace.ts

@@ -13,6 +13,9 @@ export default defineWorkspace([
       root: './space_shared',
       environment: 'happy-dom',
       setupFiles: ['./setup.jsdom.ts'],
+      provide: {
+        providedConfigValue: 'actual config value',
+      },
     },
   }),
   Promise.resolve({