How to check req.body empty or not in node ,express?

Question

Below is my request body and which is sending from client side

var  credentials = {

"ConsumerData": {

            "ConsumerStoreId": "a",
            "ConsumerUserId": "a"
        },
        "CustomerData": {

            "CustomerId": "2345678890"
        },
        "ErnD": {
            "UID": "3",
            "TxnDt": "1"
        },

        "PurD": [{
                "ItemCode": "3456tghw3",
                "ItemEANCode": "223222122"

            },
            {
                "ItemCode": "8jghw3865",
                "ItemEANCode": "3334443222"

            }
        ]
}

for testing i am sending var credentials = {} empty credentials

In server side controller(node,express) i want to check req.body empty or not

if(!req.body)

{
 console.log('Object missing');
}
if(!req.body.ConsumerData.ConsumerStoreId)
  {
  console.log('ConsumerStoreId missing');
  }
 if(!req.body.CustomerData.CustomerId)
  {
  console.log('CustomerId missing');
  }
  if(!req.body.ErnD.UID)
  {
  console.log('UID missing');
  }
    console.log('outside'); 

i am checking everything but alwasys its printing outside only

Answer 1

When the req.body is empty, it returns an empty object, as such, making !req.body return false even when it's empty. Instead, you should test for !Object.keys(req.body).length. What it will do is take every key from the object and count, if no keys where found it would return 0`. Then all we need to do is use the same method that we use on empty arrays, testing for !arr.length making it possible to receive a boolean stating it's fullness or the lack of it.

Then, we end up with the code:

router.post('/auth/signup', function(req, res) {
    if(!Object.keys(req.body).length) {
        // is empty
    } else if(!req.body.param1 || !req.body.param2 || !req.body.param3) {
        let params = [req.body.param1, req.body.param2, req.body.param3];
        let lackingParam = params.findIndex(param => !param === true) > 0 ? params.findIndex(param => !param === true) > 1 ? "req.body.param3" : "req.body.param2" : "req.body.param1";
        // lacking only lackingParam
    } else {
        // not empty
    }
});