fix(types): defineWorkspace fix intellisense and report type errors (#4743)

Author: AriPerkkio

packages/vitest/src/config.ts

@@ -30,6 +30,8 @@ export function defineProject<T extends UserProjectConfigExport>(config: T): T {
   return config
 }
 
-export function defineWorkspace<T extends (string | (UserProjectConfigExport & { extends?: string }))[]>(config: T): T {
+type Workspace = (string | (UserProjectConfigExport & { extends?: string }))
+
+export function defineWorkspace(config: Workspace[]): Workspace[] {
   return config
 }

test/config/package.json

@@ -3,7 +3,7 @@
   "type": "module",
   "private": true,
   "scripts": {
-    "test": "vitest run --typecheck"
+    "test": "vitest run --typecheck.enabled"
   },
   "devDependencies": {
     "vite": "latest",

test/config/test/config-types.test-d.ts

@@ -1,5 +1,5 @@
-import { describe, expectTypeOf, test } from 'vitest'
-import { type UserWorkspaceConfig, defineConfig, defineProject, defineWorkspace, mergeConfig } from 'vitest/config'
+import { assertType, describe, expectTypeOf, test } from 'vitest'
+import { defineConfig, defineProject, defineWorkspace, mergeConfig } from 'vitest/config'
 
 const expectMainTestConfig = expectTypeOf(defineConfig).parameter(0).resolves.toHaveProperty('test').exclude<undefined>()
 const expectProjectTestConfig = expectTypeOf(defineProject).parameter(0).resolves.toHaveProperty('test').exclude<undefined>()
@@ -26,9 +26,76 @@ describe('merge config helper', () => {
   })
 })
 
-describe('workspace config', () => {
-  test('correctly defines return type', () => {
-    expectTypeOf(defineWorkspace([{ test: { name: 'test' } }])).items.toMatchTypeOf<UserWorkspaceConfig>()
-    expectTypeOf(defineWorkspace(['packages/*'])).items.toBeString()
+describe('define workspace helper', () => {
+  type DefineWorkspaceParameter = Parameters<typeof defineWorkspace>[0]
+
+  test('allows string', () => {
+    assertType<DefineWorkspaceParameter>(['./path/to/workspace'])
+  })
+
+  test('allows config object', () => {
+    assertType<DefineWorkspaceParameter>([{
+      test: {
+        name: 'Workspace Project #1',
+        include: ['string'],
+
+        // @ts-expect-error -- Not allowed here
+        coverage: {},
+      },
+    }])
+  })
+
+  test('allows mixing strings and config objects', () => {
+    assertType<DefineWorkspaceParameter>([
+      './path/to/project',
+      {
+        test: {
+          name: 'Workspace Project #1',
+          include: ['string'],
+
+          // @ts-expect-error -- Not allowed here
+          coverage: {},
+        },
+      },
+      './path/to/another/project',
+      {
+        extends: 'workspace custom field',
+        test: {
+          name: 'Workspace Project #2',
+          include: ['string'],
+
+          // @ts-expect-error -- Not allowed here
+          coverage: {},
+        },
+      },
+    ])
+  })
+
+  test('return type matches parameters', () => {
+    expectTypeOf(defineWorkspace).returns.toMatchTypeOf<DefineWorkspaceParameter>()
+
+    expectTypeOf(defineWorkspace([
+      './path/to/project',
+      {
+        test: {
+          name: 'Workspace Project #1',
+          include: ['string'],
+
+          // @ts-expect-error -- Not allowed here
+          coverage: {},
+        },
+      },
+      './path/to/another/project',
+      {
+        extends: 'workspace custom field',
+        test: {
+          name: 'Workspace Project #2',
+          include: ['string'],
+
+          // @ts-expect-error -- Not allowed here
+          coverage: {},
+        },
+      },
+    ])).items.toMatchTypeOf<DefineWorkspaceParameter[number]>()
   })
 })