revoke.ts

import { Command } from "@oclif/command";
import chalk from "chalk";
import { ethers } from "ethers";
import { cancelled, confirm, get, getTokens } from "../lib/prompt";
import * as utils from "../lib/utils";
import { getWallet } from "../lib/wallet";

const IERC20 = require("@airswap/utils/build/src/abis/ERC20.json");
const swapDeploys = require("@airswap/swap-erc20/deploys.js");

export default class Revoke extends Command {
	public static description = "revoke a token approval";
	public async run() {
		try {
			const wallet = await getWallet(this, true);
			const chainId = (await wallet.provider.getNetwork()).chainId;
			const metadata = await utils.getMetadata(this, chainId);
			const gasPrice = await utils.getGasPrice(this);
			utils.displayDescription(this, Revoke.description, chainId);

			const { token }: any = await getTokens({ token: "token" }, metadata);
			const { contract }: any = await get({
				contract: {
					description: "swap contract",
					type: "Address",
					default: swapDeploys[chainId],
				},
			});
			this.log();

			let swapAddress = contract;
			if (!contract && swapDeploys[chainId]) {
				swapAddress = swapDeploys[chainId];
			}

			const tokenContract = new ethers.Contract(
				token.address,
				IERC20.abi,
				wallet,
			);
			const allowance = await tokenContract.allowance(
				wallet.address,
				swapAddress,
			);

			if (allowance.eq(0)) {
				this.log(
					chalk.yellow(
						`${token.symbol} is already revoked (swap contract: ${swapAddress})\n`,
					),
				);
			} else {
				if (
					await confirm(
						this,
						metadata,
						"revoke",
						{
							token: `${token.address} (${token.symbol})`,
							spender: `${swapAddress} (Swap)`,
						},
						chainId,
					)
				) {
					tokenContract
						.approve(swapAddress, "0", { gasPrice })
						.then(utils.handleTransaction)
						.catch(utils.handleError);
				}
			}
		} catch (e) {
			cancelled(e);
		}
	}
}