Check for matching values

[vectro]

Hi folks,

I am looking for a transform like this:

{
  "input": [
    {
      "a": "123",
      "b": ""
    },
    {
      "a": "",
      "b": "456"
    },
    {
      "a": "789",
      "b": "789"
    },
    {
      "a": "10",
      "b": "11"
    }
  ],
  "expected": [
    {
      "x": "123"
    },
    {
      "x": "456"
    },
    {
      "x": "789"
    },
    {
      "x": "Error!"
    }
  ]
}

This is very similar to the unique values others have mentioned with the added criterion that I want to enforce that there is only one possible value.

One idea I had was to transform the input keys into an object, then check that it has only one key. But I don't see how to match on the number of keys in JOLT?

Thanks as always for this neato tool.

[milosimpson]

I don't see a way to do that. The hard one being the duplicate "789" values.

In theory for the rest you could accumulate all non "" values into a list, and then using modify ask for the size of a each list. But there isn't a dedup the list.

[vectro]

Thanks Milo. I played around with this a little and came up with this.

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "*": {
          "": null,
          "*": "[&2].x.&"
        }
      }
    }
  },
  {
    "operation": "shift",
    "spec": {
      "*": {
        "x": {
          "*": {
            "$": "[&3].x"
          }
        }
      }
    }
  }
]

Which yields a result like this

[ {
  "x" : "123"
}, {
  "x" : "456"
}, {
  "x" : "789"
}, {
  "x" : [ "10", "11" ]
} ]

But I don't see how to go from there. Is there a way in jolt to match on object type?