TypeScript: Fix linter configuration for test files (reduxjs#3518)

* Fix linter configuration for test files

* Add separate ESLint config to test/typescript

* Also lint TypeScript files in examples


Former-commit-id: 27bf970

Author: nickserv

.eslintrc.js

@@ -30,14 +30,5 @@ module.exports = {
         argsIgnorePattern: '^_' // ignore unused variables whose name is '_'
       }
     ]
-  },
-
-  overrides: [
-    {
-      files: 'test/**/*.js',
-      env: {
-        jest: true
-      }
-    }
-  ]
+  }
 }

package.json

@@ -38,15 +38,15 @@
     "clean": "rimraf lib dist es coverage",
     "format": "prettier --write \"{src,test}/**/*.{js,ts}\" index.d.ts \"**/*.md\"",
     "format:check": "prettier --list-different \"{src,test}/**/*.{js,ts}\" index.d.ts \"**/*.md\"",
-    "lint": "eslint src test",
+    "lint": "eslint --ext js,ts src test",
     "pretest": "npm run build",
     "test": "jest",
     "test:watch": "npm test -- --watch",
     "test:cov": "npm test -- --coverage",
     "build": "rollup -c",
     "prepare": "npm run clean && npm run check-types && npm run format:check && npm run lint && npm test",
     "check-types": "tsc",
-    "examples:lint": "eslint examples",
+    "examples:lint": "eslint --ext js,ts examples",
     "examples:test": "cross-env CI=true babel-node examples/testAll.js"
   },
   "dependencies": {

test/typescript/.eslintrc.js

@@ -0,0 +1,7 @@
+module.exports = {
+  rules: {
+    'no-unused-expressions': 'off',
+    '@typescript-eslint/no-namespace': 'off',
+    '@typescript-eslint/no-unused-vars': 'off'
+  }
+}