json-dup-key-validator/test/fixture/valid-object.json

A json validator that has an option to check for duplicated keys

{
  "a": "a string value",
  "with back quote\"": [123 , 234, 345, 3.451 ],
  "with back spash\\": {
    "nested": [null, true, false  ],
    "nestedEmptyArr": [],
    "nestedEmptyObj": {}
  }
}