# wechaty-cqrs > An event-driven architecture wrapper for Wechaty that applies the CQS principle by using separate Query and Command messages to retrieve and modify the bot state, respectively. Latest version **0.12.5** (published 2022-03-28) · Apache-2.0 license · 0 weekly downloads ## Install ```sh npm install wechaty-cqrs pnpm add wechaty-cqrs yarn add wechaty-cqrs bun add wechaty-cqrs ``` ## Health **Score 30/100 (F)** — status: abandoned. Positive: has types; esm support; no vulnerabilities; high quality score. Warnings: low downloads; pre 1.0. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 0.12.5 | | Published | 2022-03-28 | | First published | 2022-03-06 | | Weekly downloads | 0 | | License | Apache-2.0 | | TypeScript types | bundled | | Module format | ESM | | Node | >=16 | | Dependencies | 9 | | Unpacked size | 1.1 MB | | Known vulnerabilities | 0 | | Install scripts | no | | Author | Huan LI | | Maintainers | zixia | | Keywords | cqrs, ddd, wechaty, chatbot, chatie | ## Links - npm: https://www.npmjs.com/package/wechaty-cqrs - Repository: https://github.com/wechaty/cqrs - Homepage: https://github.com/wechaty/cqrs#readme - Issues: https://github.com/wechaty/cqrs/issues - npm.io page: https://npm.io/package/wechaty-cqrs ## Dependencies (9) - [rxjs](https://npm.io/package/rxjs.md) ^7.5.5 - [ducks](https://npm.io/package/ducks.md) ^1.3.2 - [redux](https://npm.io/package/redux.md) ^4.1.2 - [lodash](https://npm.io/package/lodash.md) ^4.17.21 - [utility-types](https://npm.io/package/utility-types.md) ^3.10.0 - [wechaty-redux](https://npm.io/package/wechaty-redux.md) ^1.19.2 - [time-constants](https://npm.io/package/time-constants.md) ^1.0.3 - [reflect-metadata](https://npm.io/package/reflect-metadata.md) ^0.1.13 - [typesafe-actions](https://npm.io/package/typesafe-actions.md) ^5.1.0 ## Recent versions - 0.12.5 (latest) — 2022-03-28 - 0.15.4 (next) — 2022-04-22 - 0.15.3 — 2022-04-22 - 0.15.2 — 2022-04-20 - 0.13.23 — 2022-04-20 - 0.13.22 — 2022-04-20 - 0.13.21 — 2022-04-20 - 0.13.19 — 2022-04-05 - 0.13.18 — 2022-04-05 - 0.13.17 — 2022-04-04 - 0.13.16 — 2022-04-03 - 0.13.15 — 2022-04-03 - 0.13.14 — 2022-04-03 - 0.13.13 — 2022-04-03 - 0.13.12 — 2022-03-29 - … 37 more at https://npm.io/package/wechaty-cqrs/versions ## README # CQRS Wechaty [![NPM Version](https://img.shields.io/npm/v/wechaty-cqrs?color=brightgreen)](https://www.npmjs.com/package/wechaty-cqrs) [![NPM](https://github.com/wechaty/cqrs/workflows/NPM/badge.svg)](https://github.com/wechaty/cqrs/actions?query=workflow%3ANPM) [![Ducksify Extension](https://img.shields.io/badge/Redux-Ducksify-yellowgreen)](https://github.com/huan/ducks#3-ducksify-extension-currying--api-interface) [![ES Modules](https://img.shields.io/badge/ES-Modules-brightgreen)](https://github.com/Chatie/tsconfig/issues/16) An event-driven architecture wrapper for Wechaty that applies the CQS principle by using separate Query and Command messages to retrieve and modify the bot state, respectively. ![Command Query Responsibility Segregation (CQRS) Wechaty](docs/images/cqrs-wechaty.png) > Image source: [Introducing Derivative Event Sourcing](https://www.confluent.io/blog/event-sourcing-vs-derivative-event-sourcing-explained/) ## Command Query Responsibility Separation (CQRS) > Command query responsibility separation (CQRS) generalises CQS to message-driven and event-driven architectures: it applies the CQS principle by using separate Query and Command messages to retrieve and modify data, respectively. > > — [Wikipedia: Command–query separation](https://en.wikipedia.org/wiki/Command%E2%80%93query_separation) ![Command Query Responsibility Segregation (CQRS) Pattern](docs/images/cqrs-pattern.png) > Image source: [CQRS (command query responsibility segregation)](https://www.techtarget.com/searchapparchitecture/definition/CQRS-command-query-responsibility-segregation) ## Motivation Can we use Wechaty by only sending / receiving the [Plain Old JavaScript Object (POJO)](https://masteringjs.io/tutorials/fundamentals/pojo)? That's an Event-driven way, which will give us the following benifites: 1. Better integration with Domain-driven Design (DDD) 1. Decouple the sub-systems with the Wechaty instance completely 1. Enable using Wechaty with Microservices 1. Make it possible for providing an API endpoint with JSON request/responses 1. etc. So we decided to support the Event-driven Architecture by enabling the Event-driven Programming with Wechaty by publishing the [wechaty-cqrs](https://npmjs.com/package/wechaty-cqrs) NPM module. ## Features 1. Convert Wechaty instance to a messaging `bus$` with the `from()` function. 1. Well-defined `commands`, `queries`, `responses`, and `events` payload creators. 1. A great `execute$()` helper function for sending the events to the bus and get back the response. 1. Well-defined `events$` for the Wechaty events 1. Well-defined `sayables` for build all the message contents 1. Static typing with TypeScript with all events & streams 1. Working perfect with the powerful RxJS ## Usage ### Install ```sh npm install wechaty-cqrs wechaty ``` ### Quick start Here's the CQRS version of the Wechaty ding/dong bot: ```ts import * as CQRS from 'wechaty-cqrs' import * as WECHATY from 'wechaty' import { filter, map, mergeMap } from 'rxjs/operators' const wechaty = WECHATY.WechatyBuilder.build() await wechaty.init() const bus$ = CQRS.from(wechaty) bus$.pipe( filter(CQRS.isActionOf(CQRS.actions.messageReceivedEvent)), // MessageReceivedEvent -> Sayable map(messageId => CQRS.duck.actions.getSayablePayloadQuery( messageReceivedEvent.meta.puppetId, messageId, )), mergeMap(CQRS.execute$(bus$)(CQRS.duck.actions.getSayablePayloadQueryResponse)), // Log `sayable` to console ).subscribe(sayable => console.info('Sayable:', sayable), ) bus$.next(CQRS.duck.actions.startCommand(wechaty.puppet.id)) ``` ## Getting Started Here's a video introduction for CQRS Wechaty with live demo, presented by Huan: [![CQRS Wechaty Getting Started](docs/images/cqrs-wechaty-getting-started.webp)](https://youtu.be/kauxyPVa0jo) > YouTube: The getting started [ding-dong-bot.ts](https://github.com/wechaty/getting-started/blob/main/examples/cqrs/ding-dong-bot.ts) in the video: ## Diagrams ![CQRS Events Structure](docs/images/cqrs-events-diagram.svg) ```mermaid graph LR classDef event fill:DarkGoldenRod classDef command fill:blue classDef query fill:green subgraph Command C(VerbNounCommand):::command end subgraph Response RC(VerbNounCommandResponse) RQ(GetNounQueryResponse) end subgraph Query Q(GetNounQuery):::query end subgraph Event ER(ReceivedEvent):::event end C-->RC ER-->ER Q-->RQ ``` ### Command ```mermaid sequenceDiagram participant Bus participant Redux participant Wechaty Bus->>Redux: ExecuteCommand Redux->>Wechaty: Call Wechaty->>Redux: Call Return (void) Redux->>Bus: ExecuteCommandResponse ``` ### Query ```mermaid sequenceDiagram participant Bus participant Redux participant Wechaty Bus->>Redux: GetNounQuery Redux->>Wechaty: Call Wechaty->>Redux: Call Return (value) Redux->>Bus: GetNounQueryResponse ``` ### Event ```mermaid sequenceDiagram participant Bus participant Redux participant Wechaty Wechaty->>Redux: ReceivedEvent Redux->>Bus: ReceivedEvent ``` ## API Reference Read CQRS Wechaty API Reference at: ## Blogs - [Refactoring Friday BOT with NestJS, Domain-driven Design (DDD), and CQRS, @huan, Feb 27, 2022](https://wechaty.js.org/2022/02/27/refactoring-friday-bot-with-nestjs-ddd-cqrs/) ## Resources - [Layers in DDD microservices](https://docs.microsoft.com/en-us/dotnet/architecture/microservices/microservice-ddd-cqrs-patterns/ddd-oriented-microservice#layers-in-ddd-microservices) - Effective Aggregate Design - [Part I: Modeling a Single Aggregate](https://www.dddcommunity.org/wp-content/uploads/files/pdf_articles/Vernon_2011_1.pdf) - [Part II: Making Aggregates Work Together](https://www.dddcommunity.org/wp-content/uploads/files/pdf_articles/Vernon_2011_2.pdf) - [Part III: Gining Insight Through Discovery](https://www.dddcommunity.org/wp-content/uploads/files/pdf_articles/Vernon_2011_3.pdf) - [Domain-Application-Infrastructure Services pattern](https://badia-kharroubi.gitbooks.io/microservices-architecture/content/patterns/tactical-patterns/domain-application-infrastructure-services-pattern.html) ## History ### main v1.12 (Mar 27, 2022) 1. Classify action builders so that they will be compatible with Class events with NestJS [#1](https://github.com/wechaty/cqrs/issues/1) 1. `execute$()` helper function for sending the events to the bus and get back the response, with automatically type inferring. 1. lots of typing enhancements. Learn more from [PR #3](https://github.com/wechaty/cqrs/pull/3) ## v0.10 (Mar 17) Beta release - v0.9 (Mar 17,2022): Refactoring(clean) module exports - v0.7 (Mar 16, 2022): Refactoring `execute$` with `duck.actions` builders. - v0.6 (Mar 13, 2022): Alpha release. - v0.4 (Mar 13, 2022): CQRS Ding/Dong BOT works as expected. - v0.2 (Mar 11, 2022): Unit tests all passed, DevOps enabled. - v0.0.1 (Mar 6, 2022): Init README & Draft design. ## Author [Huan LI](https://github.com/huan) ([李卓桓](http://linkedin.com/in/zixia)), [Microsoft Regional Director](https://rd.microsoft.com/en-us/huan-li), [![Profile of Huan LI (李卓桓) on StackOverflow](https://stackexchange.com/users/flair/265499.png)](https://stackexchange.com/users/265499) ## Copyright & License - Code & Docs © 2022 Huan (李卓桓) \ - Code released under the Apache-2.0 License - Docs released under Creative Commons --- _Source: https://npm.io/package/wechaty-cqrs · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._