Web3 Candies 🍬🍭🍦

Sweet Web3 + TypeScript + HardHat (optional) development stack

Installation

npm install --save @defi.org/web3-candies

If not using hardhat, or running in a browser, skip the optional dependencies: --omit optional

Usage example

import { bn, bn18, bnm, ether, erc20s, erc20, account, maxUint256 } from "@defi.org/web3-candies";
import { resetNetworkFork } from "@defi.org/web3-candies/dist/hardhat"; // to allow hardhat dependencies to be optional

const x = bn18(1000.1234); // x = "1000123400000000000000" [BigNumber.js object representing wei, parsed with 18 decimals]
console.log(x.gt(ether)); // true
console.log(bnm(x).toFormat()); // prints "1,000.1234"

const owner = await account(); // web3 account [0]

console.log(await erc20s.eth.WETH().amount(123.456)); // prints 123456000000000000000
console.log(await erc20s.eth.USDC().mantissa("123123456789")); // prints 123123.456789
console.log(await erc20s.eth.USDC().to18("123456000")); // prints 123456000000000000000 (18 decimals)

const myToken = erc20("foo", myTokenAddress); // web3 instantiated ERC20 Contract
await myToken.methods.approve(other, maxUint256).send({ from: owner }); // approve max uint value for other to spend

run tests with env variable DEBUG=web3-candies to see logs

use hardhatDefaultConfig in hardhat.config.ts for sugary hardhat defaults

Sweets included

See the tests for working examples

• estimateGasPrices(): simple implementation of gas estimator for slow/avg/fast gas price

BigNumber.js utils

• bn: convert string|number|BN|BigNumber to BigNumber.js object
• bne: exponentiate n to decimals (bne(123.456789, 3) ==> 123456)
• bnm: mantissa of n in decimals (bnm(123456.789, 3) ==> 123.456789)
• bn6, bn9, bn18: convenience functions for bn with 6,9,18 decimals
• zero, one, ten, ether, maxUint256, zeroAddress: hardcoded useful values
• parsebn: parse formatted human-readable string to BigNumber.js object
• convertDecimals: convert from source decimals to target decimals

ERC20s, NFTs

• erc20s.eth/bsc/poly/arb/avax/oeth/ftm...: well known ERC20 base tokens per network
• erc20<T>(...): web3 ERC20 contract, with optional extending abi to merge
• await erc20s.eth.WETH().decimals(): memoized version of decimals method
• await erc20s.eth.WETH().amount(1.234): returns amount in wei, converted to token decimals (in this case 1234000000000000000) (memoized)
• await erc20s.eth.USDC().mantissa(123123456789): returns token amount to mantissa with decimals (in this case 123123.456789) (memoized)
• await erc20s.eth.USDC().to18(100): returns amount in 18 decimals, given amount in token decimals (in this case 100e18) (memoized)

contract utils

• contract<T>(...): create web3 Contract instance, supporting types
• deployArtifact(...): quickly deploy a compiled contract, for ex from tests
• parseEvents: parse tx receipt events
• etherscanVerify(...): verify sources for previously deployed contracts
• waitForTxConfirmations: pass tx object to wait for tx confirmations

network utils

• web3(): the globally accesible singleton. call setWeb3Instance(web3) if needed
• networks.eth/bsc/poly/arb/avax/oeth/ftm...: constants
• account: alias for web3.accounts
• block: alias for web3.getBlock, with parsed timestamp (seconds)
• findBlock: find a block closest to timestamp (millis)

hardhat utils

to allow hh to be optional, import from '@defi.org/web3-candies/dist/hardhat'

• dist/hardhat/deploy: deployment script with prompts and confirmations, saves deployment artifacts locally, waits for confirmations, optionally verifies sources on etherscan
• hardhatDefaultConfig: sweet hardhat config
• gasReportedConfig: hardhat-gas-reporter preconfigured config
• hre(): the globally accessible singleton
• tag: tag address for use with hre.tracer in logs
• artifact: read compiled artifact
• impersonate: impersonate accounts
• setBalance: sets account native token balance
• resetNetworkFork: resets the fork, with optional blockNumber
• getNetworkForkingBlockNumber, getNetworkForkingUrl: read hardhat config
• mineBlocks: mine blocks in a loop, simulating chain progression with seconds
• mineBlock: mine a single block with the given added seconds

test utils

• useChaiBigNumber(): hoist and use @defi.org/chai-bignumber mocha+chai assertions
• expectRevert: expects given fn to revert, containing reason string or regex

timing utils

• throttle(this, seconds, fn): sugar for lodash throttle
• sleep: async sleep seconds
• keepTrying: keep trying to invoke fn catching and logging exceptions, with 1 sec sleep between invocations
• preventMacSleep: runs a shell subprocess that prevents macbooks from sleeping

peerDependencies

• Default (recommended) Web3 + Hardhat development dependencies are installed
  • Use the bundled tsconfig, solhint, and other project files as a starting point

How to manually verify sources in Etherscan in case of an error during deploy?

• First, try running etherscanVerify
• After running deploy script, the deployments artifact backup should hold build-info json with all the metadata required
• Alternatively, after compiling with hardhat, ./artifacts/build-info should have this json
• Extract the object under input: this is the Solidity standard-json-input required by Etherscan
• Constructor arguments should be sent abi-encoded to Etherscan, this is printed during the deploy script, also accessible via abiEncodedConstructorArgs function