Motivation

• Currently, error handling branches for RestrictedControllerMessenger methods are not being tested on the basis of compile-time type checks.
• These branches are being ignored with the istanbul directive: /* istanbul ignore next */ // Branches unreachable with valid types
• However, given that these methods are being called by our JavaScript clients, we also need assurances on runtime error-handling behavior.

Tasks

• Add jest tests for the previously ignored error handling branches.
• Use @ts-expect-error in the tests to suppress the compile-time type errors and simulate a JavaScript environment.