Remove null values from an array in a UDF

[ptpaterson]

What is the allAllergens v4 index definition? It looks like you are only checking if the first value defined in the v4 index is a string. Are you not concerned about the second value? And is it the same order as the values defined in the v10 definition? Just making sure

You might try something like this as a v10 equivalent:

Allergens.allAllergens()
  .fold([], (acc, val) => acc.concat(val.allergens).concat(val.potential_allergens))
  .where(a => a isa String)
  .distinct()

See docs for the isa operator. Operators - Fauna Docs

And this related topic regarding that fold operation:

Using the Object.values() and flatMap() functions in v10 UDFs

To transform an array of objects like this: [ { allergens: ["foo","bar"], potential_allergens: [] }, { allergens: [], potential_allergens: ["loco"] }, // ... ] to a single array like this: [ "foo", "bar", "loco", ... ] You can use the FQL fold method. If you are familiar with Javascript, FQL’s fold method functions the same as Javascript’s reduce method without a seed value. FQL provides the separate fold method which works like Ja…