JSPM – ss-logger@1.0.7

Package Exports

ss-logger

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (ss-logger) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

ss-logger

A super simple JavaScript logger. It allows labels/tags, custom logging levels, custom output formatting and it's small. It has no dependancies.

Examples

// Standard usage
const log = require('ss-logger')();

log.info('My first info line.');
log.warn({my_obj: 'a'});
log.error('My first error line.');

// Output:
// stdout: 2017-03-10T09:44:06.391Z info: My first info line.
// stderr: 2017-03-10T09:44:06.396Z warn: {"my_obj":"a"}
// stderr: 2017-03-10T09:44:06.394Z error: My first error line.

Meta

license: Apache-2.0

createLogger

The ss-logger module returns createLogger() by default.

Parameters

label string? The label to print out on lines. Recommend not to use spaces.

Examples

// Each log line can have it's own label / tag.

const myFuncLog = require('ss-logger')('MyFunc');
const yourMethodLog = require('ss-logger')('Yours');

myFuncLog.info('My first info line.');
yourMethodLog.warn({obj: 'a'});
yourMethodLog.error('My first error line.');

// Output:
// stdout: 2017-03-10T09:44:06.391Z info MyFunc: My first info.
// stderr: 2017-03-10T09:44:06.396Z warn Yours: {"obj":"a"}
// stderr: 2017-03-10T09:44:06.394Z error Yours: My first err.

setOutput

By default the error and warn levels log output to console.error, while all other levels log output to console.log.

Parameters

output Object An object with 'log' and 'error' functions.

Examples

log.setOutput({
    error: myErrorStream
    log: myLogStream
});

Throws Error

setFormatFunction

Override the default format function. Must supply a function to handle the following parameters (date, level, fnLabel, ...msgArgs).

Parameters

newFormatFunction Function The new function to do the formatting of the output.

Examples

log.setFormatFunction(function (date, level, label, ...msgArgs) {
      const l = level.toUpperCase();
      const d = date.getTime();
      const s = msgArgs.toString();
      return `${l} ${d} ${s}`;
});
log.info('Another info line.');

// Output:
// stdout: INFO 1489198884388 Another info line.

Throws Error

setLevel

Set the log level of the logger. Anything equal to or below this level will be output. The default level is info. The available log levels are:

error
warn
info
verbose
debug
silly

Parameters

newLogLevel number The new level.

Examples

log.setLevel(log.levels.error);

log.debug('This happened!');
log.info('My first info line.');
log.warn('You have an object: ', {obj: 'a'});
log.error('My second error line.');

// Output:
// stderr: 2017-03-10T09:44:06.394Z error: My second error line.

Throws Error

Set debug log level from console

From the terminal:

DEBUG=MyFunction node app.js

Note: you can also use the following to enable debugging for all output: DEBUG=* node app.js

// app.js

const myFuncLog = require('ss-logger')('MyFunc');
const yourMethodLog = require('ss-logger')('Yours');

myFuncLog.debug('My debug message.');
yourMethodLog.debug('Your debug message');

// Output:
// stdout: 2017-03-10T09:44:06.391Z info MyFunc: My debug message.