# chpr-worker > AMQP worker library Latest version **3.2.3** (published 2019-04-12) · ISC license · 0 weekly downloads ## Install ```sh npm install chpr-worker pnpm add chpr-worker yarn add chpr-worker bun add chpr-worker ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 3.2.3 | | Published | 2019-04-12 | | First published | 2017-03-31 | | Weekly downloads | 0 | | License | ISC | | TypeScript types | none | | Module format | CommonJS | | Node | >=6.10.0 | | Dependencies | 3 | | Unpacked size | 25.4 KB | | Known vulnerabilities | 0 (+7 in 1 direct dependencies) | | Install scripts | no | | GitHub stars | 0 | | Author | Transcovo | | Maintainers | cptechadmin | | Keywords | worker, AMQP, lib | ## Links - npm: https://www.npmjs.com/package/chpr-worker - Repository: https://github.com/transcovo/chpr-worker - Homepage: https://github.com/transcovo/chpr-worker#readme - Issues: https://github.com/transcovo/chpr-worker/issues - npm.io page: https://npm.io/package/chpr-worker ## Dependencies (3) - [lodash](https://npm.io/package/lodash.md) 4.17.11 - [stakhanov](https://npm.io/package/stakhanov.md) 0.7.3 - [chpr-logger](https://npm.io/package/chpr-logger.md) 2.9.0 ## Alternatives - [@cantoo/pdf-lib](https://npm.io/package/@cantoo/pdf-lib.md) — 297.9K weekly downloads - [datatables.net-buttons](https://npm.io/package/datatables.net-buttons.md) — 200.1K weekly downloads - [@ckeditor/ckeditor5-export-pdf](https://npm.io/package/@ckeditor/ckeditor5-export-pdf.md) — 167.0K weekly downloads - [scanbot-web-sdk](https://npm.io/package/scanbot-web-sdk.md) — 15.0K weekly downloads - [@syncfusion/ej2-angular-pdfviewer](https://npm.io/package/@syncfusion/ej2-angular-pdfviewer.md) — 8.8K weekly downloads ## Recent versions - 3.2.3 (latest) — 2019-04-12 - 3.2.2 — 2018-11-26 - 3.2.1 — 2018-11-16 - 3.1.0 — 2018-11-05 - 3.0.0 — 2018-10-31 - 2.2.0 — 2018-09-28 - 2.1.2 — 2018-05-18 - 2.1.1 — 2017-12-18 - 2.1.0 — 2017-12-13 - 2.0.0 — 2017-12-13 - 1.2.0 — 2017-06-08 - 1.1.1 — 2017-06-07 - 1.1.0 — 2017-06-05 - 1.0.2 — 2017-04-05 - 1.0.1 — 2017-04-03 - … 1 more at https://npm.io/package/chpr-worker/versions ## README # chpr-worker [![CircleCI](https://circleci.com/gh/transcovo/chpr-worker.svg?style=shield)](https://circleci.com/gh/transcovo/chpr-worker) [![codecov](https://codecov.io/gh/transcovo/chpr-worker/branch/master/graph/badge.svg)](https://codecov.io/gh/transcovo/chpr-worker) chpr-worker allows you to easily create a worker that take tasks from an AMQP queue. It handles common concerns related to implementing a worker with AMQP: - Number of tasks handled at the same time - Timeout after which the task is considered as failed - Handle disconnections from the AMQP server - Validating the schema of the message specifying the task **Note:** this package is a wrapper for the **[stakhanov](https://www.npmjs.com/package/stakhanov)** open-source package. It only adds our logger via dependency injection. For up-to-date documentation, please consult the stakhanov project's [repository](https://github.com/ChauffeurPrive/stakhanov). **BREAKING CHANGE with version >= 2.x** It is not possible anymore to create a single worker by calling `createWorker`: ```javascript const worker = workerlib.createWorker({...}); ``` You should use `createWorkers` for all worker creations. **WARNING** The `queueName` configuration must be unique for each worker, otherwise messages won't necessarily be routed to the good consumer. When listening, the lib will create a queue of the form `queueName.routingKey` for each routing key/handler. That is why the queueName config must really be unique, typically of the form `application.workername`. This will generate a unique queue name per routing key, of the form `application.workername.routingkey`. Example: ```javascript function* handle(msg) { ... }; function* validate(msg) { ... }; const worker = workerlib.createWorkers([{ handle: handle, validate: validate, routingKey: 'test.something_happened' }], { workerName: 'my worker', amqpUrl: 'amqp://guest:guest@localhost:5672', exchangeName: 'bus', queueName: 'test.test_watcher' }, { channelPrefetch: 50, taskTimeout: 30000, processExitTimeout: 3000, channelCloseTimeout: 500 }); ``` ### Basic use To listen on channel: ```javascript yield worker.listen(); ``` To shutdown worker: ```javascript worker.close(); ``` Remark: for testing purpose, as the close function will execute a process.exit, you can add the following parameter to the close function: ```javascript worker.close(false); ``` By default, the `close` method will be called on SIGTERM/SIGINT signals and operate a graceful shutdown. If you want to override this behaviour (not recommended for production workers), you should specify `closeOnSignals: false` as an option. ### Events To organize your own tests, the worker instance allows you to wait for specific event with the `wait` method. Example: yield worker.wait(worker.TASK_COMPLETED); Spec: wait(event, timeout) The wait method returns a Promise which will be completed when the expected event occurs for the first time, or rejected after a timeout. `event`: name of the event, required. Must be one of the available events: - `worker.TASK_COMPLETED`: emitted when a task has been completed. - `worker.TASK_RETRIED`: emitted when a task is going to be retried because the handler has failed. - `worker.TASK_FAILED`: emitted when a task has failed because the handler has failed on a task which was already being retried. - `worker.WORKER_CLOSED`: emitted when the worker has been closed. `timeout`: timeout in milliseconds after which the promise will be rejected. Defaults to 1000 ms. ### Dev Requirements Install Node 6. For nvm users, just move to the project directory and run : nvm i If you already have installed Node 6 before, just type: nvm use --- _Source: https://npm.io/package/chpr-worker · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._