Error handling

import {
  ErrorCode,
  KashChainError,
  KashSimulationRevertedError,
  KashTransactionExpiredError,
  KashTransactionOutcomeUnknownError,
  KashValidationError,
} from '@kashdao/protocol-sdk/solana';

try {
  await kash.trades.buy({ market: 5n, outcome: 0, amountUsdc: 1_000_000n, maxSlippageBps: 100, signer });
} catch (err) {
  if (KashValidationError.is(err)) {
    // Refused before signing: nothing was sent.
    console.error('refused:', err.programError ?? err.message);
  } else if (KashSimulationRevertedError.is(err)) {
    console.error('preflight refused:', err.context?.['programError'] ?? err.message);
  } else if (KashTransactionOutcomeUnknownError.is(err)) {
    // May have landed. Look the signature up before retrying.
    console.error('outcome unknown:', err.signature);
  } else if (KashTransactionExpiredError.is(err)) {
    // Did not land. Safe to rebuild with a fresh quote and resend.
  } else if (KashChainError.is(err) && err.code === ErrorCode.TX_SEND_FAILED) {
    // The RPC refused it before forwarding. Safe to resend.
  } else {
    throw err;
  }
}