From ebd0df79baacec575dd3168318ddc13b136950ca Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 01:15:11 +0000
Subject: [PATCH 1/3] Initial plan


From db1dc39181671de9a87bf78aa7c9f66aac99c5c1 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 01:18:45 +0000
Subject: [PATCH 2/3] fix: don't set esbuild.legalComments in browser plugin
 when using rolldown-vite

Co-authored-by: hi-ogawa <4232207+hi-ogawa@users.noreply.github.com>
---
 packages/browser/src/node/plugin.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/browser/src/node/plugin.ts b/packages/browser/src/node/plugin.ts
index 6d04d71c253f..cec8f16a0f13 100644
--- a/packages/browser/src/node/plugin.ts
+++ b/packages/browser/src/node/plugin.ts
@@ -355,7 +355,9 @@ export default (parentServer: ParentBrowserProject, base = '/'): Plugin[] => {
       enforce: 'post',
       async config(viteConfig) {
         // Enables using ignore hint for coverage providers with @preserve keyword
-        if (viteConfig.esbuild !== false) {
+        // Only set esbuild options when not using rolldown-vite (Vite 8+),
+        // which uses oxc for transformation instead of esbuild
+        if (!rolldownVersion && viteConfig.esbuild !== false) {
           viteConfig.esbuild ||= {}
           viteConfig.esbuild.legalComments = 'inline'
         }

From 36b91033b5d28d2e466f288e2ab48027c1389481 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Fri, 6 Mar 2026 16:56:43 +0900
Subject: [PATCH 3/3] test: add repro

---
 test/cli/test/oxc.test.ts | 44 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 test/cli/test/oxc.test.ts

diff --git a/test/cli/test/oxc.test.ts b/test/cli/test/oxc.test.ts
new file mode 100644
index 000000000000..35f197ccfb93
--- /dev/null
+++ b/test/cli/test/oxc.test.ts
@@ -0,0 +1,44 @@
+import { runInlineTests } from '#test-utils'
+import { expect, test } from 'vitest'
+
+test('oxc config on browser', async () => {
+  const result = await runInlineTests({
+    // needs a config file to reproduce
+    // https://github.com/vitest-dev/vitest/issues/9800
+    'vitest.config.ts': `
+import { playwright } from '@vitest/browser-playwright'
+import { defineConfig } from 'vite'
+
+export default defineConfig({
+  test: {
+    browser: {
+      enabled: true,
+      headless: true,
+      provider: playwright(),
+      instances: [
+        { browser: 'chromium' },
+      ],
+    },
+  },
+  oxc: {
+    jsx: {
+      refresh: false,
+    }
+  }
+})
+`,
+    'basic.test.ts': `
+import { test } from "vitest";
+test('basic', () => {});
+`,
+  })
+
+  expect(result.stderr).toMatchInlineSnapshot(`""`)
+  expect(result.errorTree()).toMatchInlineSnapshot(`
+    {
+      "basic.test.ts": {
+        "basic": "passed",
+      },
+    }
+  `)
+})