Disable @typescript-eslint/no-non-null-asserted-optional-chain in TS 3.9

[fregante]

From: https://devblogs.microsoft.com/typescript/announcing-typescript-3-9-beta/#breaking-changes

Specifically, in previous versions, the code

foo?.bar!.baz

was interpreted to be equivalent to the following JavaScript.

(foo?.bar).baz

In the above code the parentheses stop the “short-circuiting” behavior of optional chaining, so if foo is undefined, accessing baz will cause a runtime error.

@typescript-eslint/no-non-null-asserted-optional-chain made sense in that case but TS 3.9 will change the behavior to this:

foo?.bar.baz

which just evaluates to undefined when foo is undefined.

So foo?.bar!.baz becomes perfectly reasonable to catch an undefined foo but ignore an undefined foo.bar

[sindresorhus]

Can you open an issue on https://github.com/typescript-eslint/typescript-eslint? It seems like the whole rule is moot then.

[fregante]

Done

[sindresorhus]

Closing as the issues with this rule has been fixed.