To keep destructuring legible without creating unused bindings I typically add an explanatory comment but running through prettier moves the comments to the wrong spots where it ends up obscuring the explanation

Prettier 1.13.6
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--parser babylon

Input:

const [ /* full match */, username, /* role */, /* title */, email ] = user;

Output:

const [, /* full match */ username /* role */ /* title */, , , email] = user;