Adding default values to array in Jolt

Question

I am trying to transform a json using jolt, it's just adding some default values to an array.

the input looks like this:

{
  "valueA": "A",
  "valueB": "B"
}

The output should be:

{
  "listWithItems": [ 
    {
      "valA": "A",
      "valB": "B",
      "valC": "C"
    }
  ]
}

My spec looks right now:

[
  {
    "operation": "shift",
    "spec": {
      "valueA": "listWithItems[0].valA",
      "valueB": "listWithItems[0].valB"
    }
  },
  {
    "operation": "default",
    "spec": {
      "listWithItems": [
        {
          "valC": "valC"
        }
      ]
    }
  }
]

I just can't pass the valC to the listWithItems and haven't found anything in the documentation. Can someone help me with this?

Thank you in advance!

Answer 1

One option would be changing the order of the transformations such as

[
  {
   // Add a default attribute "C" to the current object
    "operation": "default",
    "spec": {
      "valueC": "C"
    }
  },
  {
   // Nest all children of the object under "listWithItems" key name as an array
    "operation": "shift",
    "spec": {
      "*": "listWithItems[0].&"
    }
  }
]

Another option uses modify transformation such as

[
  {
   // Nest all of the current elements of the object under the "listWithItems" array 
    "operation": "shift",
    "spec": {
      "*": "listWithItems[0].&"
    }
  },
  {
   // Add new key-value pair to the array
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": {
        "*": {
          "valueC": "C"
        }
      }
    }
  }
]

You can check out https://github.com/bazaarvoice/jolt/releases/ as a source and https://jolt-demo.appspot.com/ as a playground.