There is no test suite. You’ll have to figure out if the semantics work out by testing it yourself. Sometimes I compare the minicolumn activations the SP creates to previously seen output for the similar input and make sure there is a high overlap. That at least tells you that the SP is recognizing your semantics. You can see an example of that here.
Also, for resources, be sure to search the forum. Lots of stuff about encoders here.
Also, there is this document called Building HTM Systems I’m actively working on, which has a section on encoders.