viem/utils/data/isHex.ts

TypeScript Interface for Ethereum

import type { ErrorType } from '../../errors/utils.js'
import type { Hex } from '../../types/misc.js'

export type IsHexErrorType = ErrorType

export function isHex(
  value: unknown,
  { strict = true }: { strict?: boolean | undefined } = {},
): value is Hex {
  if (!value) return false
  if (typeof value !== 'string') return false
  return strict ? /^0x[0-9a-fA-F]*$/.test(value) : value.startsWith('0x')
}