@node-dlc/bitcoin/lib/TxOut.ts

DLC bitcoin

import { BufferWriter, StreamReader } from '@node-dlc/bufio';

import { ICloneable } from './ICloneable';
import { Script } from './Script';
import { Value } from './Value';

export class TxOut implements ICloneable<TxOut> {
  /**
   * Parses a TxOut from a stream and returns a new instance of TxOut
   * @param reader
   */
  public static parse(reader: StreamReader): TxOut {
    const value = Value.fromSats(reader.readBigUInt64LE());
    const scriptPubKey = Script.parse(reader);
    return new TxOut(value, scriptPubKey);
  }

  /**
   * Parses a hex string serialization of a transaction output. This
   * is a helper function instead of having to do `StreamReader.fromHex`
   * on a string directly.
   * @param hex
   */
  public static fromHex(hex: string): TxOut {
    const reader = StreamReader.fromHex(hex);
    return TxOut.parse(reader);
  }

  /**
   * Value (often in satoshi or bitcoin) that will be locked into the
   * output using the provided scriptPubKey. The combined outputs must
   * be lte the combined input value for in transaction.
   */
  public value: Value;

  /**
   * The locking script used to encumbered the value in the output.
   * To claim these funds as an input in another transaction requires
   * providing a ScriptSig that successfully evaluates when combined
   * with the ScriptPubKey.
   */
  public scriptPubKey: Script;

  /**
   * Constructs a new TxOut from the supplied arguments
   * @param value
   * @param scriptPubKey
   */
  constructor(value: Value, scriptPubKey: Script) {
    this.value = value;
    this.scriptPubKey = scriptPubKey;
  }

  /**
   * Returns the TxOut as a string
   */
  public toString(): string {
    return `value="${this.value.sats}", scriptPubKey="${this.scriptPubKey}"`;
  }

  /**
   * Returns the TxOut as a JSON object
   */
  public toJSON(): { value: string; scriptPubKey: string } {
    return {
      value: this.value.sats.toString(),
      scriptPubKey: this.scriptPubKey.toJSON(),
    };
  }

  /**
   * Returns the serialization of the transaction output into a buffer
   */
  public serialize(): Buffer {
    const writer = new BufferWriter();
    writer.writeUInt64LE(this.value.sats);
    writer.writeBytes(this.scriptPubKey.serialize());
    return writer.toBuffer();
  }

  /**
   * Clone via deep copy
   */
  public clone(): TxOut {
    return new TxOut(this.value.clone(), this.scriptPubKey.clone());
  }
}