How do I write a FsCheck generator for an interface in C#

Question

Suppose I have an interface IPerson with 2 read properties age (int) and name (string).

I also have a class Person implementing IPerson.

How do I write a FsCheck generator for generating instances of IPerson type?

Alleman

Define "generator for IPerson" – Noumenon

I mean generator in the FsCheck meaning: fscheck.github.io/FsCheck/TestData.html – Alleman

Don't quite understand why this downvoted or being closed as unclear. It's a reasonably clear question unless you don't know what FsCheck is, but in that case just move along, nothing to see here. – Complacence

Answer 1

Something like the below should work:

Gen<IPerson> gen = from age in Arb.Default.Int32().Generator
                   from name in Arb.Default.String().Generator
                   select new Person(age, name) as IPerson;

Complacence

It works, indeed. But how can you use the "from" clause on Arb.Default.Int32().Generator, as IGen<int> does not implement IEnumerable<int>. What 's the magic? – Alleman

LINQ syntax works on any type that implements certain methods (Select, SelectMany, GroupBy etc), not just IEnumerable. Gen implements some of those. – Complacence