/chainlink-vrf-diamond

Primary LanguageSolidity

Chainlink VRF Diamond

Request Chainlink on-chain randomness following the diamond pattern (ERC-2535) for agile development.

Diamond Pattern

  • Allows to iterate development on-chain at low cost (including mainnet)
  • Organise app logic into modules with a facet per feature where storage can be shared or unique to the module

Facet's Storage

A facet can have a specific proxy storage (eternal storage, another diamonds stockage, etc...). This will depend on the evolution of the dApp complexity throught development lifecycle.

Solidstate Layout

An overview of the uses of each visibility layer is as follows:

folder layer contents description example
- 'internal' interface custom error, enum, struct, event & preferably modifier parent of IXyz.sol IRandomnessWritableInternal.sol, IRandomnessReadableInternal.sol
- interface function prototypes child of internal interfaces (e.g. IRandomnessWritable is IRandomnessWritableInternal) IRandomnessFallback.sol, IRandomnessReadble.sol, IRandomnessWritable.sol
fallback external any function visibility set of functions, which are only used when a callback is made to the diamond (e.g. VRFConsumerBaseV2.fulfillRandomWords). It can modify and/or read the state, which is why it can be nor in readable or writable only. RandomnessFallback.sol
readable external external or public functions set of functions that defines a module's getters RandomnessReadable.sol
writable external & internal any function visibility set of functions that defines a module's core logic; internal function always declares as xyzWritableInternal.sol RandomnessInternalWritable.sol, RandomnessWritable.sol
./ storage internal library functions, structs library for accessing and modifying storage; useful when sharing access to storage between implementation contracts that will be deployed separately (such as in the "diamond" proxy architecture) RandomnessStorage.sol

Versions

TBD

Common Specifications

TBD

v0.1.0:

v0.2.0:

v0.3.0:

v1.0.0: Mainnet release

EIPs To Consider

  • 2612: permit (off-chain approval)

Best Practices to Follow

Generics

  • Code formatter & linter: prettier, solhint, husky, lint-staged & husky
  • Foundry

Security

Be Prepared For Audits

  • Well refactored & commented code (NatSpec comment & PlantUML)
  • Unit (TDD) & integration (BDD) tests (green)
  • Paper code review (architecture & conception tests) - not required for this project
  • Use auditing tools (internally)
    • Secureum articles
    • Formal verification testing: solidity smt & else
    • Fuzz testing (echidna): (semi-)random inputs
    • Static analysers (mythril, slither)
    • Differential Testing
    • MythX (report)
    • Etc.. (rattle, etheno, surya…)
      • invariant testing
      • symbolic execution
      • mutation testing