Return error instead of overriding that with "unhealthy" in readers

[mateusz-sekara]

Downstream functions should return errors when errors are returned when calling RPC.
Otherwise, ChainHealthcheck will mark incorrectly chain as unhealthy.

[connorwstein]

easy to add a test?

[mateusz-sekara]

easy to add a test?

There is no easy way to mock contracts, but I will create a task to add test for that

[makramkd]

There is no easy way to mock contracts, but I will create a task to add test for that

If by mock contracts you mean mock the gethwrappers, it is pretty straightforward. abigen generates an interface that we can mock with mockery. See e.g

ccip/core/gethwrappers/ccip/go_generate.go

Line 35 in 045f2ff

//go:generate mockery --quiet --dir ./generated/evm_2_evm_onramp/ --name EVM2EVMOnRampInterface --output ./mocks/ --outpkg mock_contracts --case=underscore