@hasparus/typechain__ethers-v5
v10.0.0-rc-eth-sdk.1
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🔌 TypeChain target for ethers-v5
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Typechain target Ethers-v5
This package requires TypeScript >= 4.0. If you need support for earlier TS versions check out: 1.0 version of this package.
TypeChain readme
Contract typings
The main files generated by this target are <contract-name>.ts
. They declare typesafe interfaces for your contracts
on top of ethers Contract
instances:
- typed contract's methods, available both at
contract.someMethod(...)
andcontract.functions.someMethod(...)
- typed events in
contract.interface.events.AnEvent
and filters incontract.filters.AnEvent
- typed method gas estimates in
contract.estimateGas.someMethod
- overrides for the event listener methods (
on
,once
, etc) that return the same contract type.
Note: these are just type declarations to help you call the blockchain properly, so they're not available at runtime,
and all of the contracts are still instances of the same Contract
class.
Contract factories
This target also generates a concrete factory class for each contract, to help you deploy or connect to contract
instances. The factory classes are an extension of ethers' ContractFactory
. They serve two main purposes:
- wrap passing contract ABI and bytecode to the
ContractFactory
class, so you don't have to load and parse the JSON manually - provide a correctly typed interface to
ContractFactory
(since it returns plainContract
instances).
Abstract contracts or solidity interfaces are handled a bit different, because they have no bytecode. For those, a
simplified factory is generated that doesn't extends ContractFactory
, and only includes the static connect
method,
so you can easily connect to a deployed instance without having to pass the ABI manually.
Basic example
Suppose you have an Erc20Token.sol
solidity interface and a DummyToken.sol
contract implementing it.
import { BigNumber } from 'ethers';
import { Wallet } from 'ethers';
import { DummyTokenFactory } from 'typechain-out-dir/DummyTokenFactory';
import { DummyToken } from 'typechain-out-dir/DummyToken';
import { Erc20TokenFactory } from 'typechain-out-dir/Erc20TokenFactory';
const provider = getYourProvider(...);
// use the concrete contract factory if you need to operate on the bytecode (ie. deploy)
async function deployTestToken(ownerPK: string): Promise<DummyToken> {
const owner = new Wallet(ownerPK, provider);
return new DummyTokenFactory(owner).deploy();
}
// to call existing contracts, a factory for both the concrete contract and for the interface
// can be used since the ABI is the same
async function getTokenBalance(walletAddress: string, tokenAddress: string): Promise<BigNumber> {
const token = Erc20TokenFactory.connect(tokenAddress, provider);
return token.balanceOf(walletAddress);
}