fix(browser): ensure setup files are re-evaluated on each test run (fixes #8883)

packages/browser/src/client/tester/runner.ts

@@ -257,7 +257,9 @@ export function createBrowserRunner(
 
     importFile = async (filepath: string, mode: 'collect' | 'setup') => {
       let hash = this.hashMap.get(filepath)
-      if (!hash) {
+
+      // if the mode is setup, we need to re-evaluate the setup file on each test run
+      if (mode === 'setup' || !hash) {
         hash = Date.now().toString()
         this.hashMap.set(filepath, hash)
       }

test/browser/fixtures/isolate-and-setup-file/a.test.ts

@@ -0,0 +1,7 @@
+import { expect, test } from 'vitest'
+import { counter } from './counter'
+
+test('increment counter', () => {
+  counter.increment()
+  expect(counter.get()).toBe(1)
+});

test/browser/fixtures/isolate-and-setup-file/b.test.ts

@@ -0,0 +1,7 @@
+import { expect, test } from 'vitest'
+import { counter } from './counter'
+
+test('make sure the counter is reset by the setup file beforeEach hook', () => {
+  counter.increment()
+  expect(counter.get()).toBe(1)
+});

test/browser/fixtures/isolate-and-setup-file/browser-setup.ts

@@ -0,0 +1,4 @@
+import { beforeEach } from 'vitest'
+import { counter } from './counter'
+
+beforeEach(() => counter.reset())

test/browser/fixtures/isolate-and-setup-file/counter.ts

@@ -0,0 +1,6 @@
+const g = globalThis as unknown as { counter: number };
+export const counter = {
+  get: () => g.counter,
+  increment: () => g.counter++,
+  reset: () => (g.counter = 0),
+};

test/browser/fixtures/isolate-and-setup-file/vitest.config.ts

@@ -0,0 +1,17 @@
+import { fileURLToPath } from 'node:url'
+import { defineConfig } from 'vitest/config'
+import { instances, provider } from '../../settings'
+
+export default defineConfig({
+  cacheDir: fileURLToPath(new URL("./node_modules/.vite", import.meta.url)),
+  test: {
+    setupFiles: ['./browser-setup.ts'],
+    browser: {
+      enabled: true,
+      isolate: false,
+      provider,
+      instances,
+      headless: false,
+    },
+  },
+})

test/browser/specs/runner.test.ts

@@ -290,6 +290,13 @@ test('in-source tests run correctly when filtered', async () => {
   expect(stdout).toContain(`Tests  ${instances.length} passed`)
 })
 
+test('re-evaluate setupFiles on each test run even when isolate is false', async () => {
+  const { exitCode } = await runBrowserTests({
+    root: './fixtures/isolate-and-setup-file',
+  })
+  expect(exitCode).toBe(0)
+})
+
 test.runIf(provider.name === 'playwright')('timeout hooks', async ({ onTestFailed }) => {
   const { stderr } = await runBrowserTests({
     root: './fixtures/timeout-hooks',