feat!: drop CJS build

If you are still doing `require('@antfu/eslint-config')`, change your config name to end with `.mjs` and migrate to import.

package.json

@@ -12,10 +12,7 @@
     "eslint-config"
   ],
   "exports": {
-    ".": {
-      "import": "./dist/index.js",
-      "require": "./dist/index.cjs"
-    }
+    ".": "./dist/index.js"
   },
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
@@ -25,11 +22,11 @@
     "dist"
   ],
   "scripts": {
-    "build": "nr typegen && tsup --format esm,cjs --clean --dts",
-    "stub": "tsup --format esm",
+    "build": "nr typegen && tsup --clean --dts",
+    "stub": "tsup",
     "dev": "npx @eslint/config-inspector --config eslint.config.ts",
     "build:inspector": "pnpm build && npx @eslint/config-inspector build",
-    "watch": "tsup --format esm,cjs --watch",
+    "watch": "tsup --watch",
     "lint": "eslint .",
     "typegen": "tsx scripts/typegen.ts",
     "prepack": "nr build",

test/cli.spec.ts

@@ -61,14 +61,6 @@ it('esm eslint.config.js', async () => {
   expect(stdout).toContain('Created eslint.config.js')
 })
 
-it('cjs eslint.config.mjs', async () => {
-  const { stdout } = await run()
-
-  const eslintConfigContent = await fs.readFile(join(genPath, 'eslint.config.mjs'), 'utf-8')
-  expect(eslintConfigContent.includes('export default')).toBeTruthy()
-  expect(stdout).toContain('Created eslint.config.mjs')
-})
-
 it('ignores files added in eslint.config.js', async () => {
   const { stdout } = await run()
 

tsup.config.ts

@@ -6,4 +6,5 @@ export default defineConfig({
     'src/cli.ts',
   ],
   shims: true,
+  format: ['esm'],
 })