Add tests & simplify logic

[scooprinder]

I agree with the comments made in 1 and as such haven't made any modifications to errors or syntax.

Simplified the logic for the register / revoke functions, though upon further reflection these could be improved further (perhaps with different storage layouts). Knocked off around 45k gas from register and around 10k gas from revoke.

I added some simple forge tests to cover the base use cases and found the following issues:

• The require(registeredDelegation[globalHash] == false); check in registerDelegationAddress means that it is impossible to add more than one delegationAddresses per hash (which makes the most of the mapping redundant).
• Both retrieveActiveFromDelegations and retrieveActiveToDelegations create fixed size arrays matching all delegations. This means that it could return an array with address(0) elements. For example, if the delegationAddresses[] for a given hash has 3 entries, two of which are expired in slots 0 and 1 then with the current implementation would return [0x000..., 0x000..., <delegation address>] - for large array sizes this would require further processing to get the correct information.
• Counter mappings weren't strictly necessary, could just use the length of the returning delegationAddresses[] for a given hash.

The code in this PR isn't perfect either (only had a little bit of time) but I think some more fundamental changes are required - I'm submitting it because it could be some help but no drama if it isn't.

[scooprinder]

Apologies for the delay @rookmate - I appreciate your feedback; are these tests still wanted? I can tidy the PR up this week if so.

[rookmate]

Apologies for the delay @rookmate - I appreciate your feedback; are these tests still wanted? I can tidy the PR up this week if so.

Hey mate! Me and @brookr from PR #19 really want it! :pray: Although we're waiting for the repo owner to come alive and also provide feedback in the PRs...

I just noticed they did more than a few changes a few days ago :thinking: If I get some time this week I'll do another pass on the open PRs

[a2rocket]

outdated PR