Ethers.js binding for contract interfaces

ethers-bindings.ts

import { Dependencies, AbiFunction, AbiParameter, Transaction } from './generated/liquid-long'
import { keccak256, toUtf8Bytes, BigNumber, AbiCoder } from 'ethers/utils'
import { TransactionResponse, TransactionRequest } from 'ethers/providers';

export interface Provider {
    listAccounts(): Promise<Array<string>>
    call(transaction: TransactionRequest): Promise<string>
}

export interface Signer {
    sendTransaction(transaction: TransactionRequest): Promise<TransactionResponse>;
}

export class ContractDependenciesEthers implements Dependencies<BigNumber> {
    private readonly provider: Provider
    private readonly signer: Signer
    public constructor(provider: Provider, signer: Signer) {
        this.provider = provider
        this.signer = signer
    }

    keccak256 = (utf8String: string) => keccak256(toUtf8Bytes(utf8String))
    encodeParams = (abiFunction: AbiFunction, parameters: Array<any>) => new AbiCoder().encode(abiFunction.inputs, parameters).substr(2)
    decodeParams = (abiParameters: Array<AbiParameter>, encoded: string) => new AbiCoder().decode(abiParameters, encoded)
    getDefaultAddress = async () => (await this.provider.listAccounts())[0]
    call = async (transaction: Transaction<BigNumber>) => await this.provider.call(transaction)
    submitTransaction = async (transaction: Transaction<BigNumber>) => {
        // https://github.com/ethers-io/ethers.js/issues/321
        transaction = Object.assign({}, transaction)
        delete transaction.from
        return { status: (await (await this.signer.sendTransaction(transaction)).wait()).status! }
    }
}