JSONata: How to get all paths from the payload?

Question

How to get all the paths of the input object and traverse it according to my wish.

One such use case is I want to convert the value of all except few fields/nested fields in a object to uppercase.

For example, assume below is the input,

{
  "name": "John",
    "age": 30,
    "bio": "I am a software developer.",
    "username": "john_doe",
    "profiles": [
        {
            "network": "Twitter",
            "username": "john_doe"
        },
        {
            "network": "Facebook",
            "username": "john_doe"
        }
    ]
}

For the above payload, I want to convert all values to uppercase, except for $.username and $.profiles.username. In this case, I would know only which are those fields to except, not the paths to convert.

Output for above would be,

{
  "name": "JOHN",
    "age": 30,
    "bio": "I AM A SOFTWARE DEVELOPER.",
    "username": "john_doe",
    "profiles": [
        {
            "network": "TWITTER",
            "username": "john_doe"
        },
        {
            "network": "FACEBOOK",
            "username": "john_doe"
        }
    ]
}

How to achieve this using JSONata ?

Answer 1

You can write a recursive function to dig deep into your object and then replace values that match your criteria:

(
  $recurse := function($object) {
    (
      $type($object) = "object"
        ? $merge($each($object, function($value, $key) { 
            { 
              $key: $type($value) = "string" and $key != "username"
                ? $uppercase($value)
                : $recurse($value)
            } 
          }))
        : $type($object) = "array"
          ? $map($object, $recurse)
          : $object
    )
  };

  $recurse($)
)

Check it out on the Stedi playground: https://stedi.link/HYL5ebO