fix(runner): support fixture parsing of lowered async syntax (#6531)

packages/runner/src/fixture.ts

@@ -212,7 +212,14 @@ function resolveDeps(
 }
 
 function getUsedProps(fn: Function) {
-  const match = fn.toString().match(/[^(]*\(([^)]*)/)
+  let fnString = fn.toString()
+  // match lowered async function and strip it off
+  //   (_0) => __async(this, [_0], function* (x) { ... })
+  //   (_0, _1) => __async(this, [_0, _1], function* (x, y) { ... })
+  if (/^\([_0-9, ]*\)\s*=>\s*__async\(this,/.test(fnString)) {
+    fnString = fnString.split('__async(this,')[1]
+  }
+  const match = fnString.match(/[^(]*\(([^)]*)/)
   if (!match) {
     return []
   }

test/config/fixtures/fixture-no-async/basic.test.ts

@@ -0,0 +1,37 @@
+import { test as base, expect } from "vitest";
+
+type Fixture = {
+  simple: string,
+  nested: string,
+}
+
+const test = base.extend<Fixture>({
+  simple: async ({}, use) => {
+    await use("simple");
+  },
+  nested: async ({ simple }, use) => {
+    await use("nested:" + simple);
+  },
+});
+
+test("test sync", ({ simple, nested }) => {
+  expect(simple).toBe("simple");
+  expect(nested).toBe("nested:simple")
+});
+
+test("test async", async ({ simple, nested }) => {
+  expect(simple).toBe("simple");
+  expect(nested).toBe("nested:simple")
+});
+
+test.for([1, 2])("test.for sync %i", (i, { expect, simple, nested }) => {
+  expect(i).toBeTypeOf("number")
+  expect(simple).toBe("simple");
+  expect(nested).toBe("nested:simple")
+})
+
+test.for([1, 2])("test.for async %i", async (i, { expect, simple, nested }) => {
+  expect(i).toBeTypeOf("number")
+  expect(simple).toBe("simple");
+  expect(nested).toBe("nested:simple")
+})

test/config/fixtures/fixture-no-async/vitest.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  esbuild: {
+    supported: {
+      "async-await": false,
+    },
+  },
+});

test/config/test/fixture-no-async.test.ts

@@ -0,0 +1,21 @@
+import path from 'node:path'
+import { expect, test } from 'vitest'
+import { runVitest } from '../../test-utils'
+
+test('fixture parsing works for lowered async syntax', async () => {
+  const { stdout } = await runVitest({
+    root: path.resolve('fixtures/fixture-no-async'),
+    reporters: ['tap-flat'],
+  })
+  expect(stdout.replaceAll(/\s*# time=.*/g, '')).toMatchInlineSnapshot(`
+    "TAP version 13
+    1..6
+    ok 1 - basic.test.ts > test sync
+    ok 2 - basic.test.ts > test async
+    ok 3 - basic.test.ts > test.for sync 1
+    ok 4 - basic.test.ts > test.for sync 2
+    ok 5 - basic.test.ts > test.for async 1
+    ok 6 - basic.test.ts > test.for async 2
+    "
+  `)
+})