import { Signer } from 'ethers';
import { BigNumber } from '@ethersproject/bignumber';
import { Token } from '../entities';
/**
 * get contract allowance for token
 * @param signer ethers.js signer
 * @param tokenAddress the address of token to be approved
 * @param contractAddress spender address
 */
export declare function readAllowance(signer: Signer, tokenAddress: string, contractAddress: string): Promise<BigNumber>;
export declare function getApprovedAmount(signer: Signer, token: Token, approvalAddress: string): Promise<string | undefined>;
export declare function approveToken(signer: Signer, token: Token, amount: string, approvalAddress: string, unlimitedAmount?: boolean): Promise<void>;
export declare function revokeTokenApproval(signer: Signer, token: Token, approvalAddress: string): Promise<void>;