Write PHOTWAPOracle Contracts && Tests

[steve0xp]

Write PHOTWAPOracle Contracts && Tests

Core changes:

• Write oracle contracts based off of feedback on heavy research phase && draft PR Feat: write oracle contracts and tests #33
• Write tests for new oracle contracts
• Update draft Figjam to go with new PHOTWAPOracle arrangement
• Queue up what will be needed for integration into rest of code-base (separate PR)
  • This will be revisited once more robust tests are written && new protocol architecture is flushed out.

Notes:

• Some issues occurred with running tests altogether, using forge test, essentially tests took way longer than anticipated (or not at all really in full). So I simply run forge test -vvv --match-contract PHOTWAPOracle
• A lot of the TWAP concepts are derived from this, among other resources.

Figjam screenshot for visual:

• I will be writing some github issues tomorrow, including what to do when price fluctuates widely, right now we just revert when the priceUpdateThreshold is exceeded.
• Effects on USD/PHO price from adding and removing liquidity are not included in the tests currently, can and will likely address these tomorrow, but these tests as is are good for showcasing basic functionality for PHOTWAPOracle.sol
• PR Feat: write oracle contracts and tests #33 available for reference, but it has a lot of outdated conversation topics.

[steve0xp]

Notes/Comments from Kevin in draft PR #33 outlined here for continued discussion:

#33 (comment)

#33 (comment)

#33 (comment)

[davekaj]

I only skimmed the tests as I don't have time and we have other higher priorities.

But I went over the code in depth. Please fix all requests.

When we merge this we need to add a TODO to write more tests for this oracle. basically f from what I see, we just copy paste the Solidity into the tests and test the same function against itself. it's not the most useful kind of test.

we could write the tests in another environment.

but more importantly, we need to run a more aggressive test against this oracle, put it in a more realistic scenario, simulate a few hundred deposits and then see if everything is still returning the right price. we'd also have to run tests to push the oracle to its limits (where slippage occurs)

[steve0xp]

I will address your change requests and add a TODO for more tests within the oracle test file. Are we saying to make the changes requested and submit the oracle code and tests as is though before adding such complex oracle tests? I think the more complicated oracle tests in their own PR is fair.

[steve0xp]

I have addressed all requested changes, and opened up appropriate issues for any outstanding tasks outside of the scope of this PR (ex. contingency plans).

One carry-over comment / change requested by Kevin was to switch the arrays to single vars. I wonder if there is really much benefit to doing this. I could but just wondering before making the change.

ref: #33 (comment)

[steve0xp]

Final changes have been made and ready for review.