Using the `!!` operator seems to be a frequent sou...

# announcements

[Jacques Smuts]

Using the !! operator seems to be a frequent source of issues. Has anyone here ever considered turning !! into a compiler-error lint rule?

[Sławomir Onyszko]

I'm scared of this operator and my friends are scared of this too but lint rule would be awesome

[Jacques Smuts]

I’m not used to writing my own lint rules but this should be an easy one 🤔 .

But it’s quite a hard-rule so not sure if it’s a good idea

[LeoColman]

I feel that if a lint rule is added, people will start doing

val foo = getPossibleNullable() ?: throw IllegalStateException("Shouldn't be null")

[LeoColman]

Which would be exactly the same

[LeoColman]

Sometimes you just know a variable won't be null at some point, and I believe it's ok to go !! for that scenario

[streetsofboston]

Using !! shouldn't be a Lint warning, but you should carefully examine your code why you'd need it! Often it's a code-smell, but sometimes there's no other way 😀

[Mike]

Detekt has this as a rule, and allows easy Suppression of rules if it’s determined to be valid/acceptable.

[Jacques Smuts]

I like that idea.

[Jessie]

I didn’t know we can create our own Lint rules, that’d be a great idea, but what we’ve done is that we don’t allow the !! operator, so in our code review we are really aware about it. We prefer to have a null check before using an expression that is coming from Java and might need that dangerous operator.