Add an infix variant of shouldNotBeNull that accepts a block

[sschuberth]

This allows for some syntactic sugar when dealing with the non-null value.

[Kantis]

It's currently possible to do either:

// Typical method chaining
            a.shouldNotBeNull()
              .shouldHaveLength(3)
              .shouldStartWith("fo")
              .shouldEndWith("oo")

// or, using Kotlin features
            a.run {
               shoudNotBeNull()
               shouldHaveLength(3)
               shouldStartWith("fo")
               shouldEndWith("oo")
            }

Are there other use-cases where this syntax provides a bigger difference?

[sschuberth]

Are there other use-cases where this syntax provides a bigger difference?

I don't thinks so. And you're right in saying that this is just syntactic sugar over using

.shouldNotBeNull().run {

Mine is just slightly shorter an (arguably) a tad more readable due to the infix notation.

[Kantis]

You can do run before even? shouldNotBeNull has a compiler contract which makes the compiler narrow the type to non-null if shouldNotBeNull passes

[sschuberth]

You can do run before even?

Not sure what you mean, can you give an example?

shouldNotBeNull has a compiler contract

Yes, I'm aware of that. However, that contract does not work if .shouldNotBeNull() is used on a property that "is a public API property declared in a different module".

In my current case,

receiveResponse.messages.shouldNotBeNull()
receiveResponse.messages.forEach {  } // Smart cast impossible here.

does not work for that reason. Thus I prefer a syntax with a block in whose scope the property becomes non-nullable. So,

receiveResponse.messages.shouldNotBeNull().run { forEach {} }

works, but still

receiveResponse.messages shouldNotBeNull { forEach {} }

reads a bit nicer, IMO.

[Kantis]

Thanks, that's a good point 🙂