feat: initial corpus — React monorepo with 4 cross-package bugs

Tier 3 e2e corpus for QuantCode autonomous agent testing.
Bugs:
- packages/utils/src/format/date.ts: formatDate produces US-style dates (Math.floor field ordering)
- packages/ui/src/components/Button/Button.tsx: icon-only button aria-label not applied to DOM element
- packages/ui/src/components/DataTable/DataTable.tsx: stale closure in sort handler
- apps/web/src/lib/api.ts: imports useThrottle (renamed to useDebounce)

Test infra: bunfig.toml preload for happy-dom, cleanup() in React tests

Author: stooit

.gitignore

@@ -0,0 +1,5 @@
+node_modules/
+bun.lock
+*.lock
+dist/
+.DS_Store

bunfig.toml

@@ -0,0 +1,2 @@
+[test]
+environment = "happy-dom"

package.json

@@ -8,14 +8,18 @@
     "apps/*"
   ],
   "scripts": {
-    "test": "bun test --recursive",
+    "test": "bun test packages/utils/test packages/ui/test apps/web/test --preload ./packages/ui/test/setup.ts",
     "typecheck": "tsc --noEmit"
   },
   "devDependencies": {
     "typescript": "^5.4.0",
     "bun-types": "latest",
     "@types/react": "^18.3.0",
     "react": "^18.3.0",
-    "react-dom": "^18.3.0"
+    "react-dom": "^18.3.0",
+    "@testing-library/react": "^16.0.0",
+    "@testing-library/jest-dom": "^6.4.0",
+    "happy-dom": "^14.0.0",
+    "@happy-dom/global-registrator": "^14.0.0"
   }
 }

packages/ui/bunfig.toml

@@ -0,0 +1,2 @@
+[test]
+preload = ["./test/setup.ts"]

packages/ui/test/Button.test.tsx

@@ -1,9 +1,11 @@
-import { describe, test, expect } from "bun:test"
-import { render } from "@testing-library/react"
+import { describe, test, expect, afterEach } from "bun:test"
+import { render, cleanup } from "@testing-library/react"
 import { Button } from "../src/components/Button/Button"
 import React from "react"
 
 describe("Button", () => {
+  afterEach(() => cleanup())
+
   test("renders with text", () => {
     const { getByText } = render(<Button>Click me</Button>)
     expect(getByText("Click me")).toBeDefined()

packages/ui/test/DataTable.test.tsx

@@ -1,5 +1,5 @@
-import { describe, test, expect } from "bun:test"
-import { render, fireEvent } from "@testing-library/react"
+import { describe, test, expect, afterEach } from "bun:test"
+import { render, fireEvent, cleanup } from "@testing-library/react"
 import { DataTable } from "../src/components/DataTable/DataTable"
 import React from "react"
 
@@ -15,6 +15,8 @@ const columns = [
 ]
 
 describe("DataTable", () => {
+  afterEach(() => cleanup())
+
   test("renders all rows", () => {
     const { getByText } = render(<DataTable data={data} columns={columns} />)
     expect(getByText("Alice")).toBeDefined()

packages/ui/test/setup.ts

@@ -0,0 +1,3 @@
+// Set up happy-dom for React component tests
+import { GlobalRegistrator } from "@happy-dom/global-registrator"
+GlobalRegistrator.register()