Check for nullity using "is null" or "is object"

[blairconrad]

Jared Parsons lays out the reasons in
https://twitter.com/jaredpar/status/1171478965355024384:

... "x is object" is either a) a null check or b) does
not compile. In the case "x" is known to be a struct the compiler will
emit a diagnostic.

Similarly "x is null" has the same properties except it's always a
null check vs. a non-null check

[blairconrad]

You seemed excited when I mentioned this, @thomaslevesque. Feel like making @jaredpar happier by two developers?

[thomaslevesque]

You seemed excited when I mentioned this, @thomaslevesque.

Not excited enough to go over the whole code base to replace usages of == null and != null, but since you were motivated enough to do it... Why not 😉

Thanks @blairconrad, LGTM!

[thomaslevesque]

You'll need to squash before I can merge, though

[blairconrad]

Not excited enough to go over the whole code base to replace usages of == null and != null

Search and replace is a wonderful thing.

You mean with the latest SDK we can do (x is null) even when x could be a struct?

You can at least do it when T is an unconstrained typeparam.

Ah! I just tried with an int, and the i is null test caused the build to fail.

Squashed! Thanks for the review and eventual merge.

[thomaslevesque]

Thanks @blairconrad !

[jaredpar]

This makes me happy 😄

[blairconrad]

This change has been released as part of FakeItEasy 5.3.0.