Arbitrary records with optional fields

💬 Question and Help

Hi, I have an interface with optional fields, something like:

interface Foo {
  bar?: number
}

I am trying to generate arbitraries for this, but fc.option(fc.integer()) doesn’t seem to do the trick, since it always includes the property (typed as number | null). I’d like to omit the property entirely as optional, but I believe I can settle for number | undefined.

What’s the best way to do this?

Thanks!

[gnidan]

Thank you @dubzzz! I just ran into this situation again and was quite surprised to see that past-me opened this issue over a year ago! And that you fixed it!

[dubzzz]

@gnidan The feature is now native in fast-check 2.11.0 🥳

Look for record and requiredKeys in https://github.com/dubzzz/fast-check/blob/master/documentation/Arbitraries.md#object