Cross-proxy

An isolated core abstraction layer for integrating various messaging systems such as Kafka, RabbitMQ, etc., enabling seamless communication and interchangeability based on the @nestjs/microservices.

To install the project:

npm install cross-proxy

How to use

There will be a class that must be extended by your core. There will be ready-made public methods and there will also be abstract methods that must be implemented in their core. this.routingMap is used to store asynchronous message callbacks and this.handlers is used to store callbacks that will be executed when a particular topic is called.

import {
  IMessageOptionsDTO,
  IPatternDTO,
  IReadPacketDTO,
  IWritePacketDTO,
  Proxy,
} from 'cross-proxy';

/**
 * @description The type parameter `T` in `Proxy<T>` should represent the message options specific to the implementation.
 * */
export class YourCore extends Proxy<unknown> {
  public constructor() {
    super(30000);
  }

  /**
   * @description Init your connection
   * */
  protected connect(): Promise<unknown> {}

  /**
   * @description Close your connections
   * */
  protected closeConnections(): Promise<unknown> {}

  /**
   * @description Subscribe a channel
   * */
  protected subscribe(pattern: IPatternDTO): void {}

  /**
   * @description A parser from cross-proxy message options to your core message options
   * */
  protected serializeMessageOptions(options?: IMessageOptionsDTO): unknown {}

  /**
   * @description Deserialize the message
   * */
  protected deserializeMessage<Input>(
    value: Input,
    message: unknown,
  ): IWritePacketDTO<Input> & { id: string } {}

  /**
   * @description Decode a value to a friendly result
   * */
  protected decode<Input, Val>(value: Val): Input | string | null | Buffer {}

  /**
   * @description Set a callback to execute by a topic
   * @example
   * // Must use this inside it plus your core business rules
   * this.handlers.set(topic, handlers)
   * */
  protected setListener<T, X>(data: {
    pattern: IPatternDTO;
    handlers: Array<(data: IWritePacketDTO<T>) => X>;
  }): void {}

  /**
   * @description Publish a message, this method will be used to "send" method
   * @example
   * // Must use this inside it plus your core business rules
   * const packet = this.assignPacketId(partialPacket);
   * this.routingMap.set(packet.replyId, callback);
   * */
  protected publish<Input, Output>(data: {
    partialPacket: IReadPacketDTO<Input, IMessageOptionsDTO>;
    callback: (packet: IWritePacketDTO<Output>) => void;
  }): () => void | undefined {}

  /**
   * @description Publish a message, this method will be used to "emit" method
   * */
  protected dispatchEvent<Input>(
    packet: IReadPacketDTO<Input, IMessageOptionsDTO>,
  ): Promise<unknown> {}
}