asyncctx

node-async-context (asyncctx)

This module allows you to create an asynchronous execution context for JavaScript or TypeScript

NOTE: This module is based on async_hooks an experimental built-in node.js module introduced in v8.0.0

Deprecation

NOTE: This module is now deprecated in favour of AsyncLocalStorage which is available for nodejs >= 12

quick start using AsyncLocalStorage

 class ContinuationLocalStorage<T> extends AsyncLocalStorage<T> {
   public getContext(): T | undefined {
      return this.getStore();
    }
    public setContext(value: T): T {
      this.enterWith(value);
      return value;
    }
  }

Introduction

To give you an idea of how asyncctx is supposed to be used:

import { ContinuationLocalStorage } from 'asyncctx';

class MyLocalStorage {
  value: number;
}

let cls = new ContinuationLocalStorage<MyLocalStorage>();
cls.setRootContext({ value: 1});

process.nextTick(() => {
  let curr1 = cls.getContext(); // value is 1
  cls.setContext({ value: 2});  // value should be 2 in the current execution context and below
  process.nextTick(() => {
    let curr2 = cls.getContext(); // value is 2
    cls.setContext({ value: 3});  // value should be 3 in the current execution context and below
    process.nextTick(() => {
      let curr3 = cls.getContext(); // value is 3
    });
  });
  process.nextTick(() => {
    let curr4 = cls.getContext(); // value is 2
  });
});

License

node-async-context (asyncctx) is licensed under the MIT License: LICENSE

Release Notes

Release	Notes
2.1.0	maintenance release
2.0.18-19	deprecated in favour of AsyncLocalStorage
2.0.12-17	maintenance release, nodejs 14 support
2.0.11	#54: fixed memory leak for chaining asynchronous calls infinitely; thanks to Reko Tiira
2.0.10	maintenance release
2.0.9	node 13 supported
2.0.3-8	maintenance release
2.0.2	#47: fixed loosing context for unknown resource types; thanks to Pasi Tuominen
2.0.1	maintenance release
2.0.0	targeting es2015; dropped support for nodejs < v8
	please use asyncctx@<2.0 for nodejs v4 - v11 support
1.1.0	fixed support for nodes < v8
1.0.5-10	maintenance release
1.0.4	node 10 supported
1.0.3	node 9 supported
1.0.2	maintenance release
1.0.1	added support for older nodejs versions (4,6,7) using internal copy of async-hook@1.7.1
1.0.0	is now based on 'async_hooks' (a built-in nodejs v8.0 module)
0.0.6	maintenance releases
0.0.5	async-hook 1.7.1
0.0.1-4	initial version