vitest-dev
diff --git a/‎packages/vitest/src/api/setup.ts‎
Lines changed: 1 addition & 1 deletion b/‎packages/vitest/src/api/setup.ts‎
Lines changed: 1 addition & 1 deletion
diff --git a/‎packages/vitest/src/node/core.ts‎
Lines changed: 17 additions & 2 deletions b/‎packages/vitest/src/node/core.ts‎
Lines changed: 17 additions & 2 deletions
diff --git a/‎test/browser/specs/projects-ui.test.ts‎
Lines changed: 44 additions & 0 deletions b/‎test/browser/specs/projects-ui.test.ts‎
Lines changed: 44 additions & 0 deletions
@@ -215,7 +215,7 @@ export function setup(ctx: Vitest, _server?: ViteDevServer): void {
   ctx.reporters.push(new WebSocketReporter(ctx, wss, clients))
 }
 
-export class WebSocketReporter implements Reporter {
+class WebSocketReporter implements Reporter {
   private start = 0
   private end = 0
   constructor(
 
@@ -26,6 +26,7 @@ import { deepClone, deepMerge, nanoid, noop, toArray } from '@vitest/utils/helpe
 import { serializeValue } from '@vitest/utils/serialize'
 import { join, normalize, relative } from 'pathe'
 import { version } from '../../package.json' with { type: 'json' }
+import { setup as wsApiSetup } from '../api/setup'
 import { defaultBrowserPort } from '../constants'
 import { distDir } from '../paths'
 import { createTagsFilter } from '../runtime/runner/utils/tags'
@@ -447,8 +448,22 @@ export class Vitest {
     // root-level browser server the API lives on the same shared httpServer and
     // is only needed when a UI (Vitest dashboard or browser orchestrator) is served.
     const apiNeeded = !this._rootBrowserParent || resolved.ui || resolved.browser.ui
-    if (resolved.api && resolved.watch && apiNeeded) {
-      (await import('../api/setup')).setup(this)
+    const rootApi = resolved.api && resolved.watch && apiNeeded
+    if (rootApi) {
+      wsApiSetup(this)
+    }
+
+    const attachedApiServers = new Set([rootApi ? this.vite.httpServer : null])
+    for (const project of this.projects) {
+      const browserServer = project.vite
+      if (
+        project.config.browser.ui
+        && browserServer?.httpServer
+        && !attachedApiServers.has(browserServer.httpServer)
+      ) {
+        attachedApiServers.add(browserServer.httpServer)
+        wsApiSetup(this, browserServer)
+      }
     }
 
     await this._fsCache.ensureCacheIntegrity()
 
@@ -0,0 +1,44 @@
+import { expect, test } from 'vitest'
+import { runInlineTests } from '../../test-utils'
+import { provider } from '../settings'
+
+test.runIf(provider.name === 'playwright')('browser ui enabled in projects setup (#10993)', async () => {
+  const { stderr, exitCode, testTree } = await runInlineTests(
+    {
+      'basic.test.ts': `
+        import { expect, test } from 'vitest'
+
+        test('works', () => {
+          expect(1 + 1).toBe(2)
+        })
+      `,
+    },
+    {
+      watch: false,
+      reporters: 'none',
+      projects: [
+        {
+          test: {
+            browser: {
+              enabled: true,
+              headless: true,
+              ui: true,
+              provider,
+              instances: [{ browser: 'chromium' }],
+            },
+          },
+        },
+      ],
+    },
+  )
+
+  expect(stderr).toBe('')
+  expect(exitCode).toBe(0)
+  expect(testTree()).toMatchInlineSnapshot(`
+    {
+      "basic.test.ts": {
+        "works": "passed",
+      },
+    }
+  `)
+})
Original file line number	Diff line number	Diff line change
`@@ -215,7 +215,7 @@ export function setup(ctx: Vitest, _server?: ViteDevServer): void {`
`215`	`215`	`ctx.reporters.push(new WebSocketReporter(ctx, wss, clients))`
`216`	`216`	`}`
`217`	`217`
`218`		`-export class WebSocketReporter implements Reporter {`
	`218`	`+class WebSocketReporter implements Reporter {`
`219`	`219`	`private start = 0`
`220`	`220`	`private end = 0`
`221`	`221`	`constructor(`