This repo contains all contracts and tests relevant to the core xEmbr protocol.

Core xEmbr contracts utilise OpenZeppelin's InitializableAdminUpgradeabilityProxy to facilitate future upgrades, fixes or feature additions. The upgrades are proposed by the xEmbr Governors (with current governor address stored in the Fulcrum - the system kernel) and executed via the DelayedProxyAdmin. Both changes to the governor, and contract upgrades have a one week delay built in to execution. This allows xEmbr users a one week opt out window if they do not agree with the given change.

🏠 https://embr.finanace
📄 https://docs.embr.finanace

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Branches

• master contains complete, tested and audited contract code, generally on mainnet
• beta is for the pre-release code, generally on ropsten

Dev notes

Prerequisites

• Node.js v10.22.0 (you may wish to use nvm)
• ganache-cli

Installing dependencies

$ yarn

Testing

Tests are written with Hardhat, Ethers, Waffle & Typescript, using Typechain to generate typings for all contracts. Tests are executed using hardhat in hardhats evm.

$ yarn test

Suite

Key folders:

• /contracts/z_mocks: All mocks used throughout the test suite
• /security: Scripts used to run static analysis tools like Slither and Securify
• /test: Unit tests in folders corresponding to contracts/xx
• /test-utils: Core util files used throughout the test framework
  • /machines: Mock contract machines for creating configurable instances of the contracts
• /types: TS Types used throughout the suite
  • /generated: Output from Typechain; strongly-typed, Ethers-flavoured contract interfaces

CI

Codebase rules are enforced through a passing CI (visible in .circleci/config.yml). These rules are:

• Linting of both the contracts (through Solium) and TS files (ESLint)
• Passing test suite
• Maintaining high unit testing coverage

Code formatting

• Solidity imports deconstructed as import { xxx } from "../xxx.sol"
• Solidity commented as per NatSpec format
• Internal function ordering from high > low order

Command Line Interface

Hardhat Tasks are used for command line interactions with the mStable contracts. The tasks can be found in the tasks folder.

A separate Hardhat config file tasks.config.ts is used for task config. This inherits from the main Hardhat config file hardhat.config.ts. This avoids circular dependencies when the repository needs to be compiled before the Typechain artifacts have been generated. This means the --config tasks.config.ts Hardhat option needs to be used to run the mStable tasks.

Config your network. If you are just using readonly tasks like mBTC-snap you don't need to have a signer with Ether in it so the default Hardhat test account is ok to use. For safety, the mainnet config is not committed to the repository to avoid accidentally running tasks against mainnet.

mainnet: {
    url: process.env.NODE_URL || "",
    accounts: {
        mnemonic: "test test test test test test test test test test test junk",
    },
},

Never commit mainnet private keys, mnemonics or provider URLs to the repository.

Examples of using the Hardhat tasks

# List all Hardhat tasks
hh --config tasks.config.ts

# Set the provider url
export NODE_URL=https://mainnet.infura.io/v3/yourApiKey

# To run the mBTC-snap task against mainnet
yarn task mBTC-snap --network mainnet