Spread syntax in Jsonata?

Question

I would like to just add a key/value pair to a object and therefore not enlist all of the objects attributes again. Something similar to javascripts ... Spread syntax.

{
    'address': $.customer.addresses[id=$$.shippingAddressId].{
        ...?,
        'fullName': firstName & ' ' & lastName
    }
}

I looked through the documentation and searched the web, but could not find anything regarding this feature.

What were I expecting?

Actually, I would have been surprised if it had been implemented, but since Jsonata is so awesome, it could have been.

EDITED:

You can write the transformation like this (improves readablility):

{
    'address': $.customer.addresses[id=$$.shippingAddressId].{
        'street': street,
        'city': city,
        'fullName': firstName & ' ' & lastName
    }
}

The question stems from pure curiosity

If someone knows a better way, I would be interested, otherwise I will continue to marvel at its beauty.

Answer 1

If I'm understanding the question correctly, given the following data (I had to make some assumptions because no data was provided):

Data

{
  "customer": {
    "firstName": "Alex",
    "lastName": "Jäger",
    "addresses": [
      {"id": "home", "street": "123 Main Street", "city": "MyTown"},
      {"id": "work", "street": "987 South Street", "city": "AnyTown", "spreadMeInAlso": "something"},
      {"id": "school", "street": "654 North Street", "city": "YourTown"}
    ]
  },
  "shippingAddressId": "work"
}

Query

This query, using the Transform Operator, will allow you to create the fullName and essentially "spread in" the remaining values:

{
    'address': $.customer.addresses[id=$$.shippingAddressId] ~> | $ | {
        "fullName": $$.customer.firstName & ' ' & $$.customer.lastName
    } |
}

Output

{
  "address": {
    "id": "work",
    "street": "987 South Street",
    "city": "AnyTown",
    "spreadMeInAlso": "something",
    "fullName": "Alex Jäger"
  }
}

Working example: https://try.jsonata.org/Py1y6SOqe