expect_setequal doesn't work on lists (document?)

[MichaelChirico]

I'd expect the following test to pass: expect_setequal(list(a = 1:4, b = 4:1), list(b = 4:1, a = 1:4)), but it fails because the inputs are sorted with sort.int, which doesn't know how to handle a list.

I was attempting to replace a test of the form expect_equal(my_list[order(names(my_list))], list(a = 1:4, b = 4:1)).

If there's disagreement about whether these objects should be considered setequal, at the very least we need to document the acceptable types (atomic?) to be passed to object as ?expect_setequal only says:

object	object to test

[kevinykuo]

This feels like a bug; one would expect expect_setequal() to pass if setequal is TRUE.

[kevinushey]

I agree this would be nice to have.

[hadley]

Set equality ignores names:

setequal(
  list(a = 1:4, b = 4:1), 
  list(d = 4:1, e = 1:4)
)
#> [1] TRUE

^{Created on 2019-03-28 by the reprex package (v0.2.1.9000)}

But maybe expect_setequal() should use an implementation closer to setequal() and avoiding sorting. We could using something like all(vec_in(x, y)) && all(vec_in(y, x)). The error reporting will be a bit trickier though.