Error.decodeParams

import { AbiError } from 'tevm'

const errors = [
  new AbiError({
    type: "error",
    name: "InsufficientBalance",
    inputs: [
      { type: "uint256", name: "balance" },
      { type: "uint256", name: "required" }
    ]
  }),
  new AbiError({
    type: "error",
    name: "Unauthorized",
    inputs: [{ type: "address", name: "caller" }]
  })
]

// Create error registry
const errorRegistry = new Map(
  errors.map(e => [e.getSelector(), e])
)

try {
  await contract.call()
} catch (error) {
  const selector = error.data.slice(0, 10)
  const abiError = errorRegistry.get(selector)

  if (abiError) {
    const params = abiError.decodeParams(error.data)
    console.log(`Error: ${abiError.name}`, params)
  }
}