fix: detect fixture that returns without calling use (#9831)

packages/runner/src/fixture.ts

@@ -5,6 +5,8 @@ import { FixtureAccessError, FixtureDependencyError, FixtureParseError } from '.
 import { getTestFixtures } from './map'
 import { getCurrentSuite } from './suite'
 
+const FIXTURE_STACK_TRACE_KEY = Symbol.for('VITEST_FIXTURE_STACK_TRACE')
+
 export interface TestFixtureItem extends FixtureOptions {
   name: string
   value: unknown
@@ -187,6 +189,10 @@ export class TestFixtures {
         parent,
       }
 
+      if (isFixtureFunction(value)) {
+        Object.assign(value, { [FIXTURE_STACK_TRACE_KEY]: new Error('STACK_TRACE_ERROR') })
+      }
+
       registrations.set(name, item)
 
       if (item.scope === 'worker' && (runner.pool === 'vmThreads' || runner.pool === 'vmForks')) {
@@ -427,6 +433,7 @@ function resolveTestFixtureValue(
 
   return resolveFixtureFunction(
     fixture.value,
+    fixture.name,
     context,
     cleanupFnArray,
   )
@@ -463,6 +470,7 @@ async function resolveScopeFixtureValue(
 
   const promise = resolveFixtureFunction(
     fixture.value,
+    fixture.name,
     fixture.scope === 'file' ? { ...workerContext, ...fileContext } : fixtureContext,
     cleanupFnFileArray,
   ).then((value) => {
@@ -479,11 +487,16 @@ async function resolveFixtureFunction(
     context: unknown,
     useFn: (arg: unknown) => Promise<void>,
   ) => Promise<void>,
+  fixtureName: string,
   context: unknown,
   cleanupFnArray: (() => void | Promise<void>)[],
 ): Promise<unknown> {
   // wait for `use` call to extract fixture value
   const useFnArgPromise = createDefer()
+  const stackTraceError
+    = FIXTURE_STACK_TRACE_KEY in fixtureFn && fixtureFn[FIXTURE_STACK_TRACE_KEY] instanceof Error
+      ? fixtureFn[FIXTURE_STACK_TRACE_KEY]
+      : undefined
   let isUseFnArgResolved = false
 
   const fixtureReturn = fixtureFn(context, async (useFnArg: unknown) => {
@@ -500,6 +513,17 @@ async function resolveFixtureFunction(
       await fixtureReturn
     })
     await useReturnPromise
+  }).then(() => {
+    // fixture returned without calling use()
+    if (!isUseFnArgResolved) {
+      const error = new Error(
+        `Fixture "${fixtureName}" returned without calling "use". Make sure to call "use" in every code path of the fixture function.`,
+      )
+      if (stackTraceError?.stack) {
+        error.stack = error.message + stackTraceError.stack.replace(stackTraceError.message, '')
+      }
+      useFnArgPromise.reject(error)
+    }
   }).catch((e: unknown) => {
     // treat fixture setup error as test failure
     if (!isUseFnArgResolved) {

test/cli/test/scoped-fixtures.test.ts

@@ -53,6 +53,48 @@ test('test fixture cannot import from file fixture', async () => {
   `)
 })
 
+test('fixture returned without calling use', async () => {
+  const { stderr } = await runInlineTests({
+    'basic.test.ts': () => {
+      const extendedTest = it.extend<{
+        value: string | undefined
+        setup: void
+      }>({
+        value: undefined,
+        setup: [
+          async ({ value }, use) => {
+            if (!value) {
+              return
+            }
+            await use(undefined)
+          },
+          { auto: true },
+        ],
+      })
+
+      extendedTest('should fail with descriptive error', () => {})
+    },
+  }, { globals: true })
+  expect(stderr).toMatchInlineSnapshot(`
+    "
+    ⎯⎯⎯⎯⎯⎯⎯ Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯
+
+     FAIL  basic.test.ts > should fail with descriptive error
+    Error: Fixture "setup" returned without calling "use". Make sure to call "use" in every code path of the fixture function.
+     ❯ basic.test.ts:2:27
+          1| await (() => {
+          2|   const extendedTest = it.extend({
+           |                           ^
+          3|     value: void 0,
+          4|     setup: [
+     ❯ basic.test.ts:16:1
+
+    ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯
+
+    "
+  `)
+})
+
 test('can import file fixture inside the local fixture', async () => {
   const { stderr, fixtures, tests } = await runFixtureTests(({ log }) => it.extend<{
     file: string