refmt removes parents leading to invalid code

[jchavarri]

Input:

let {foo: (_: int)} = 2;

Output:

let {foo: _: int} = 2;

Also applies to switch expressions, using destruct in let to simplify the repro.

[anmonteiro]

What's an example of switch expression failing? or did you mean pattern?

[jchavarri]

Yes, I meant pattern (I think you already figured it out 😄 thanks!)