Simplify service JSON marshalling We don't need to have a MarshalJSON method just so that it can be created ok. It's clearer to do stuff necessart for object creation at the time of object creation, not way earlier in some unrelated bit of the code. While here simplify the tests to actually test what we're worried about.

panic on unlikely test case We're just in test mode, so it's ok to panic if we reach this highly unlikely scenario when, for example, the testdata file changes or something.

Use default MarshalJSON method There's no point doing so much manual work and testing just to keep fields under a "attrs" key when marshalling to JSON. When creating the object we can just: 1. Marshal the object to JSON 2. Put it all under a "attrs" key. Now it's easier to imagine the mapping of the structs to JSON, since they follow the same rules as everything else in Go.

Keep test data in version control While here also don't log messages in testing unless there's an error.

Handle last check result of services Includes a test to know that we're handling the JSON properly.