Should throw on async () => await 5 ** 6;

[fisker]

Babel PR babel/babel#12441

[3cp]

I am not very clear about the issue.
Does this come from an ambiguous spec on the precedence of "await" and "**"?

[3cp]

tc39/ecma262#2197
https://github.com/tc39/notes/blob/master/meetings/2020-11/nov-16.md#handling-await-in-left-operands-of-exponentiation

I am little surprised to see the discussion is all about the spec on left operands of exponentiation. Nobody talked about the precedence of operators??

[3cp]

I could not find precedence discussed there.

[3cp]

Now I understand bit more, Estree defined ecma ExponentiationExpression inside BinaryExpression.
But ExponentiationExpression requires left operand to be UpdateExpression, while BinaryExpression does not do special check when operator is ** (highest precedence).

[3cp]

I need to check more. Our code seems rejecting other Non-UpdateExpreesion just fine +2**2, delete 2**2.