The optional chaining operator ?. allows to access a deeply nested property, returning undefined if the property or any
intermediate object is undefined.
This usually means that the expression is expected to evaluate as undefined in some cases. Therefore, using the optional chaining
operator in a context where returning undefined throws an error can lead to runtime exceptions.
(event?.callback)(); // Noncompliant: when 'event' does not have 'callback' property TypeError is thrown
const { code } = event?.error; // Noncompliant: when 'event' does not have 'error' property TypeError is thrown
func(...event?.values); // Noncompliant: when 'event' does not have 'values' property TypeError is thrown
Since optional chaining represents multiple execution branches, having an error thrown in such a context can be hard to debug.
