[no-void]: allow void arrow functions

What rule do you want to change? no-void

Does this change cause the rule to produce more or fewer warnings? Fewer

How will the change be implemented? (New option, new default behavior, etc.)? Option - could also be implemented as standard behaviour depending on interpretation of the rules description.

Please provide some example code that this change will affect:

const log = x => void console.log(x);

What does the rule currently do for this code? Errors

What will the rule do after it’s changed? Not error

Are you willing to submit a pull request to implement this change? Yes

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There are some legitimate uses for the void operator, one of which is even mentioned in the opening sentence of the no-void docs:

It can be used to ignore any side effects expression may produce

The description of the no-void rule to me seems to indicate that the rule is actually ideally about preventing the use of void to get a “pure” undefined back in the pre-ES5 days when undefined was mutable:

The common case of using void operator is to get a “pure” undefined value as prior to ES5 the undefined variable was mutable:

So it might be arguable that this is technically a bug? But I don’t have a major preference on if it’s an option or not 😃

Based off #12688, which was closed for not following the template.

[ljharb]

undefined is still mutable, post-ES5, just not in the global scope.

[G-Rath]

@kaicataldo sure thing 🙂