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postfix operator (no-non-null-assertion)Using non-null assertions cancels the benefits of the strict null-checking mode.
Examples of incorrect code for this rule:
interface Foo { bar?: string; } const foo: Foo = getFoo(); const includesBaz: boolean = foo.bar!.includes('baz');
Examples of correct code for this rule:
interface Foo { bar?: string; } const foo: Foo = getFoo(); const includesBaz: boolean = foo.bar && foo.bar.includes('baz');
If you don't care about strict null-checking, then you will not need this rule.