Get the revert reason before sending an Ethereum transaction if the transaction would fail

revert.ts

export async function tryGetRevertReason(to: string, from: string, data: string): Promise<string | undefined> {
  const provider = ethers.getDefaultProvider();
  const tx = { to, from, data };
  try {
    await provider.estimateGas(tx);
  } catch {
    const value = await provider.call(tx);
    return hexDataLength(value) % 32 === 4 && hexDataSlice(value, 0, 4) === '0x08c379a0'
      ? defaultAbiCoder.decode(['string'], hexDataSlice(value, 4))
      : undefined;
  }

  return undefined;
}