Fix: prefer-exponentiation-operator invalid autofix with await

[mdjermanovic]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "X" next to an item)

[ ] Documentation update
[x] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

This is similar to #12739

Tell us about your environment

• ESLint Version: v7.15.0
• Node Version: v12.18.4
• npm Version: v6.14.6

What parser (default, @babel/eslint-parser, @typescript-eslint/parser, etc.) are you using?

default

Please show your full configuration:

Configuration

module.exports = {
  parserOptions: {
    ecmaVersion: 2017
  }
};

What did you do? Please include the actual source code causing the issue.

Online Demo

/* eslint prefer-exponentiation-operator: error */

async () => Math.pow(await a, b)

What did you expect to happen?

await expression without parens cannot be left-hand side of an exponentiation expression, so the following autofix is expected:

/* eslint prefer-exponentiation-operator: error */

async () => (await a)**b

What actually happened? Please include the actual, raw output from ESLint.

autofix:

/* eslint prefer-exponentiation-operator: error */

async () => await a**b

What changes did you make? (Give an overview)

Fixed the prefer-exponentiation-operator rule to add parens around await before **.

Is there anything you'd like reviewers to focus on?

[yeonjuan]

LGTM!