From fcb9660c846695c4cb4f7f7e3e9a82c1c73ab17c Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Fri, 27 Feb 2026 15:42:12 +0900
Subject: [PATCH] test: test oxc decorators and coverage (#9738)

---
 package.json                                  |  1 +
 .../configs/vitest.config.decorators.ts       |  2 +-
 test/coverage-test/test/decorators.test.ts    | 42 ++++++++++++++++---
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/package.json b/package.json
index d730c927c..4f6de9a7d 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
     "ui:build": "vite build packages/ui",
     "ui:dev": "npm -C packages/ui run dev:client",
     "ui:test": "npm -C packages/ui run test:run",
+    "override-rolldown": "yq -i '.overrides.vite = \"npm:vite@beta\"' pnpm-workspace.yaml",
     "test:browser:webdriverio": "pnpm -C test/browser run test:webdriverio",
     "test:browser:playwright": "pnpm -C test/browser run test:playwright"
   },
diff --git a/test/coverage-test/fixtures/configs/vitest.config.decorators.ts b/test/coverage-test/fixtures/configs/vitest.config.decorators.ts
index 120015c3a..4d942fee1 100644
--- a/test/coverage-test/fixtures/configs/vitest.config.decorators.ts
+++ b/test/coverage-test/fixtures/configs/vitest.config.decorators.ts
@@ -7,7 +7,7 @@ import base from "./vitest.config";
 export default mergeConfig(
   base,
   defineConfig({
-    plugins: [DecoratorsPlugin()],
+    plugins: process.env.TEST_OXC_DECORATOR ? [] : [DecoratorsPlugin()],
     test: {},
   })
 );
diff --git a/test/coverage-test/test/decorators.test.ts b/test/coverage-test/test/decorators.test.ts
index b25124a8d..475780bba 100644
--- a/test/coverage-test/test/decorators.test.ts
+++ b/test/coverage-test/test/decorators.test.ts
@@ -1,4 +1,5 @@
-import { expect } from 'vitest'
+import { expect, vi } from 'vitest'
+import { rolldownVersion } from 'vitest/node'
 import { DecoratorsTester } from '../fixtures/src/decorators'
 import { coverageTest, normalizeURL, readCoverageMap, runVitest, test } from '../utils'
 
@@ -14,14 +15,45 @@ test('decorators generated metadata is ignored', async () => {
   const lineCoverage = fileCoverage.getLineCoverage()
   const branchCoverage = fileCoverage.getBranchCoverageByLine()
 
-  expect(lineCoverage['4']).toBeUndefined()
-  expect(branchCoverage['4']).toBeUndefined()
+  expect.soft(lineCoverage['4']).toBeUndefined()
+  expect.soft(branchCoverage['4']).toBeUndefined()
 
   // Covered branch should be marked correctly
-  expect(lineCoverage['7']).toBe(1)
+  expect.soft(lineCoverage['7']).toBe(1)
 
   // Uncovered branch should be marked correctly
-  expect(lineCoverage['12']).toBe(0)
+  expect.soft(lineCoverage['12']).toBe(0)
+})
+
+test('decorators generated metadata is covered with OXC decorators', async ({ onTestFinished }) => {
+  if (!rolldownVersion) {
+    return
+  }
+
+  vi.stubEnv('TEST_OXC_DECORATOR', 'true')
+  onTestFinished(() => {
+    vi.unstubAllEnvs()
+  })
+
+  await runVitest({
+    include: [normalizeURL(import.meta.url)],
+    config: 'fixtures/configs/vitest.config.decorators.ts',
+    coverage: { reporter: ['json', 'html'] },
+  })
+
+  const coverageMap = await readCoverageMap()
+  const fileCoverage = coverageMap.fileCoverageFor('<process-cwd>/fixtures/src/decorators.ts')
+  const lineCoverage = fileCoverage.getLineCoverage()
+  const branchCoverage = fileCoverage.getBranchCoverageByLine()
+
+  expect.soft(lineCoverage['4']).toBe(1) // this is different from SWC case above
+  expect.soft(branchCoverage['4']).toBeUndefined()
+
+  // Covered branch should be marked correctly
+  expect.soft(lineCoverage['7']).toBe(1)
+
+  // Uncovered branch should be marked correctly
+  expect.soft(lineCoverage['12']).toBe(0)
 })
 
 coverageTest('cover decorators', () => {
-- 
2.51.2