Konsol NPM | npm.io

konsol

Author: Kurt Pattyn.

Konsol is a drop-in replacement for the node.js console. It adds the ability to enable and disable the output.
Suppression of the output can be controlled at run-time through the enable and disable static methods, or at start-time through the use of the KONSOL environment variable.

Motivation

When using modules, one often wants to see debug output from those modules.
During normal operation these messages should not be shown. But during development these messages can be very helpful for debugging.
Also during production it can be very helpful to be able to also get log output from included modules (e.g. in case of troubleshooting).
By using Konsol you can log messages just like with console from within your own modules, but Konsol adds the capability to enable or surpress its output.
By default output is disabled.

Installation

$ npm install konsol

$ npm install konsol --production

for a production only installation (no tests, documentation, ...).

Usage

  var konsol = require("konsol")("mymodule");
  ...
  //we use konsol instead of console to do our logging
  konsol.log("...");  //or info, warn, err, ...
  
  module.exports = mymodule;

Running node mymodule.js will generate no output (default behaviour).
When we run KONSOL=mymodule node mymodule.js the output will enabled and written the stdout.

Output can also programmatically enabled and disabled:

  var Konsol = require("konsol");
  Konsol.enable("mymodule");
  var mm = require("mymodule");

In the above example, the output of mymodule will be visible.

API

Konsol(moduleName)

Used in a (sub)module for logging. Registers moduleName with Konsol and returns a Konsol logger.

Parameters

moduleName (String, required): name of the module; this name should match the name by which the module is known to the end-user
Although not strictly required, it is good practice to use the same name as the name by which the module is known to the end-user. In the case of Konsol for instance, this would be konsol.

Example

  var konsol = require("konsol")("mymodule");

  konsol.log("The sky is blue.");
  //can also use .info, .warn, .error, .dir, .time, .timeEnd

static Konsol.enable(moduleName)

Enables output for the given moduleName.

Parameters

moduleName (String, required): name of the module to enable output for

Example

  var myModule = require("mymodule");
  var Konsol = require("konsol");

  Konsol.enable("mymodule");
  //from now, all output of mymodule will be redirected to the console.

static Konsol.disable(moduleName)

Disables output for the given moduleName.

Parameters

moduleName (String, required): name of the module to disable output for

Example

  var myModule = require("mymodule");
  var Konsol = require("konsol");

  Konsol.disable("mymodule");
  //from now, all output of Konsol will be suppressed.

`KONSOL` Environment Variable

By default, all Konsol output is suppressed. Output can be enabled either by calling Konsol.enable() or by setting the KONSOL environment variable.
E.g. calling Konsol.enable("mymodule") is the same as starting node with KONSOL=mymodule node myapp.js.

The difference between setting the KONSOL environment variable and calling Konsol.enable() is that the enable() method can change the output at run-time.

The KONSOL environment variable is a comma- and/or space-separated list of modules for which to enable the output.
E.g.
KONSOL=mymodule, yourmodule node app.js
is the same as
KONSOL=mymodule yourmodule node app.js

Tests

Unit Tests

$ npm test

Unit Tests with Code Coverage

$ npm run test-cov

This will generate a folder coverage containing coverage information and a folder coverage/lcov-report containing an HTML report with the coverage results.

$ npm run test-ci

will create a folder coverage containing lcov formatted coverage information to be consumed by a 3rd party coverage analysis tool. This script is typically used on a continuous integration server.