hardhat-tracer/src/utils/hex.ts

Hardhat Tracer plugin

import { BigNumber, BigNumberish } from "ethers";
import {
  arrayify,
  hexDataSlice,
  hexlify,
  hexStripZeros,
  hexZeroPad,
} from "ethers/lib/utils";

/**
 * Ensures 0x prefix to a hex string which may or may not
 * @param str A hex string that may or may not have 0x prepended
 */
export function hexPrefix(str: string) {
  return !str.startsWith("0x") ? "0x" + str : str;
}

export function parseNumber(str: string) {
  return parseUint(str).toNumber();
}

export function parseUint(str: string) {
  return BigNumber.from(hexPrefix(str));
}

export function parseAddress(str: string) {
  return hexZeroPad(hexStripZeros(hexPrefix(str)), 20);
}

export function parseBytes32(str: string) {
  return hexZeroPad(hexStripZeros(hexPrefix(str)), 32);
}

export function parseMemory(strArr: string[]) {
  return arrayify(hexPrefix(strArr.join("")));
}

export function shallowCopyStack(stack: string[]): string[] {
  return [...stack];
}

export function shallowCopyStack2(stack: Array<bigint>): string[] {
  return [...stack].map((x) => BigNumber.from(x).toHexString());
}

export function toAddr(val: BigNumberish) {
  return hexZeroPad(hexlify(val), 20);
}

export function memorySlice(
  buffer?: Uint8Array,
  offset?: number,
  length?: number
): string {
  if (!buffer) {
    throw new Error("memory is undefined");
  }
  if (offset !== undefined && length !== undefined) {
    return hexDataSlice(buffer, offset, offset + length);
  } else {
    return "0x";
  }
}