fix(eslint-plugin-query): add footer workaround for CJS default export in modernConfig (TanStack#8991)

Author: Newbie012

examples/react/eslint-legacy/.eslintrc

@@ -1,3 +1,5 @@
 {
+  "parser": "@typescript-eslint/parser",
+  "plugins": ["@typescript-eslint"],
   "extends": ["plugin:@tanstack/query/recommended"]
 }

examples/react/eslint-legacy/package.json

@@ -6,7 +6,7 @@
     "dev": "vite",
     "build": "vite build",
     "preview": "vite preview",
-    "test:eslint": "eslint ./src"
+    "test:eslint": "ESLINT_USE_FLAT_CONFIG=false eslint ./src/**/*.tsx"
   },
   "dependencies": {
     "@tanstack/query-sync-storage-persister": "^5.73.1",
@@ -18,11 +18,19 @@
   },
   "devDependencies": {
     "@tanstack/eslint-plugin-query": "^5.72.2",
-    "eslint": "^8.16.0",
     "@types/react": "^18.2.79",
     "@types/react-dom": "^18.2.25",
     "@vitejs/plugin-react": "^4.3.4",
     "typescript": "5.8.2",
     "vite": "^6.2.4"
+  },
+  "nx": {
+    "targets": {
+      "test:eslint": {
+        "dependsOn": [
+          "^build"
+        ]
+      }
+    }
   }
 }

examples/react/eslint-legacy/tsconfig.json

@@ -20,5 +20,5 @@
     "noUnusedParameters": true,
     "noFallthroughCasesInSwitch": true
   },
-  "include": ["src", "eslint.config.js"]
+  "include": ["src"]
 }

packages/eslint-plugin-query/root.tsup.config.js

@@ -15,6 +15,15 @@ export function modernConfig(opts) {
     sourcemap: true,
     clean: true,
     external: ['typescript'],
+    footer: ({ format }) => {
+      if (format === 'cjs') {
+        // workaround for CJS default export
+        // @see https://github.com/evanw/esbuild/issues/1182#issuecomment-1011414271
+        return { js: `module.exports = module.exports.default` }
+      }
+
+      return
+    },
   }
 }