Parenthesized non-null assertion in an optional chain

[bradzacher]

Prettier 2.0.5
Playground link

# Options (if any):
--parser=typescript

Input:

(x?.y)!.z

Output:

x?.y!.z;

Expected behavior:

(x?.y)!.z

---

As of TS 3.9, x?.y!.z no longer means (x?.y).z.
Instead, the ! is applied solely to the type of the property y, preserving the optionality of the chain (i.e. x?.y!.z is the same as x?.y.z, and (x?.y)!.z is the same as (x?.y).z).

This means that now automatically removing the parentheses in this case is wrong, and changes the meaning of the code.

[sosukesuzuki]

note: we should wait typescript-eslint/typescript-eslint#2036

[sosukesuzuki]

We also need to wait typescript-eslint/typescript-eslint#2057 to avoid warning.

[bradzacher]

typescript-eslint/typescript-eslint#2057 will be released on monday morning :)