Valid $set stages in aggregation pipeline are not parsed correctly and show errors. This also affects importing of text-based aggregation pipelines.

The following are valid $set stage definitions. They run fine as part of a larger pipeline using NodeJS and were used using mongo shell to create a view from the same pipeline, but cannot be imported in Compass without showing errors:

{
    "$set": {
      "profile": {
        "$arrayElemAt": [
          "$profile_array",
          0
        ]
      }
    }
  }

and....

{
    "$set": {
      "sort_status": {
        "$indexOfArray": [
          [
            "H",
            "N",
            "0"
          ],
          "$medical_status_code"
        ]
      }
    }
  }