✨ Bytes32AddressLib: `fromFirst20Bytes`

[kphed]

Description

Add a method for converting a right-padded bytes32 address (e.g. return value of fillLast12Bytes) back into the original 20-byte address.

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• [x] Ran forge snapshot?
• [x] Ran npm run lint?
• [x] Ran forge test?

[transmissions11]

awesome! can you add a fuzz test to ensure they're inverses over all inputs, and a plain unit test that just checks the output of fromFirst20Bytes without running it through fillLast12Bytes?

[kphed]

awesome! can you add a fuzz test to ensure they're inverses over all inputs, and a plain unit test that just checks the output of fromFirst20Bytes without running it through fillLast12Bytes?

Thanks for looking, done ser.

For the unit test, I'm reusing the same address-based values as what's in testFillLast12Bytes so I created contract variables to reduce code duplication. I wanted to bring that up since it resulted in a change to the testFillLast12Bytes test (now uses the new variables). If that's not ok, I'll change it back.

In the fuzz test, I have an equality assertion for the output of fillLast12Bytes and the bytes32-casted input because I think many people will use fillLast12Bytes and fromFirst20Bytes in tandem (we're currently doing this).