write logs to js Array

Usage no npm install needed!

<script type="module">
  import winstonArrayTransport from '';



write winston logs directly to javascript Array.

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Table of Contents


There are a lot of cases where you need to parse and analyze your logs. For example, to access them during tests. This package provides transport that allows simply push logs to js array, so you don't need any runtime parsers anymore.


Platform Status

To use library you need to have node and npm installed in your machine:

  • node >=10
  • npm >=6

Package is continuously tested on darwin, linux, win32 platforms. All active and maintenance LTS node releases are supported.


To install the library run the following command

  npm i --save winston-array-transport


The package can be used alongside any other winston transport.

import ArrayTransport from 'winston-array-transport';
import { createLogger } from 'winston';

const logs = [];
const transport  = new ArrayTransport({ array: logs, json: true, level: 'info' });

export const logger = createLogger({
    transports : [ transport ]


Next options can be configured while transport creation:

  • name - name of a transport, ArrayTransport by default;
  • eol - end of line , os.EOL by default;
  • array - array, where all logs will be stored;
  • parser - function, that will be applied to log messages;
  • json - if set to true, JSON.parse parser will be used;
  • limit - allows to limit amount of logs to n last items;


Make the changes to the code and tests. Then commit to your branch. Be sure to follow the commit message conventions. Read Contributing Guidelines for details.