Disallows using a non-null assertion after an optional chain expression (no-non-null-asserted-optional-chain
)
Optional chain expressions are designed to return undefined
if the optional property is nullish.
Using non-null assertions after an optional chain expression is wrong, and introduces a serious type safety hole into your code.
Examples of incorrect code for this rule:
/* eslint @typescript-eslint/no-non-null-asserted-optional-chain: "error" */
foo?.bar!;
foo?.bar!.baz;
foo?.bar()!;
foo?.bar!();
foo?.bar!().baz;
Examples of correct code for this rule:
/* eslint @typescript-eslint/no-non-null-asserted-optional-chain: "error" */
foo?.bar;
(foo?.bar).baz;
foo?.bar();
foo?.bar();
foo?.bar().baz;
If you are not using TypeScript 3.7 (or greater), then you will not need to use this rule, as the operator is not supported.