Function calculateCleanupSize

packages/cashscript/src/debugging.ts:321–343

(instructions: Array<AuthenticationInstruction | undefined>)

};

const calculateCleanupSize = (instructions: Array<AuthenticationInstruction | undefined>): number => {
  // OP_NIP (or OP_DROP/OP_2DROP in optimised bytecode) is used for cleanup at the end of a function,
  // OP_ENDIF and OP_ELSE are the end of branches. We need to remove all of these to get to the actual last
  // executed instruction of a function
  // Note that in the case where we re-add OP_1 because we cannot optimise the final explicit VERIFY into an implicit one
  // (like when dealing with if-statements, or with CHECKLOCKTIMEVERIFY), it is impossible to run into an implicit final
  // verify failure. That is why OP_1 does not need to be included in the cleanup opcodes.
  // TODO: Perhaps we also do not need to add OP_DROP/OP_2DROP either, because they only occur together with OP_1
  const cleanupOpcodes = [Op.OP_ENDIF, Op.OP_NIP, Op.OP_ELSE, Op.OP_DROP, Op.OP_2DROP];

  let cleanupSize = 0;
  for (const instruction of [...instructions].reverse()) {
    // The instructions array may contain undefined elements for the final executed debug steps that are not
    // technically instructions (e.g. the final *implicit* verify). We still want to get rid of these in the cleanup
    if (!instruction || cleanupOpcodes.includes(instruction.opcode)) {
      cleanupSize++;
    } else {
      break;
    }
  }

  return cleanupSize;
};

// eslint-disable-next-line @typescript-eslint/no-unused-vars
const logDebugSteps = (