jsclass-logger

Logger which works perfectly both in production/debug environment.

What Makes "jsclass-logger" Unique

While there are many proven logging libraries, including famous "Winston", "jsclass-logger" focuses on ease of use. Check out the code below.

let logger;

// setup logger for production output
logger = require("jsclass-logger")();

// setup logger to output log with module name
logger = require("jsclass-logger")({}, "your_module_name");

// setup logger for development output
logger = require("jsclass-logger")({"debug":true});

// setup logger for file output
logger = require("jsclass-logger")({"toFile":true});

Here is an output sample.

// normal message
logger.info("log message");

> 2018-10-16 00:17:17.008 INFO  (test.js:34:20) log message

// object dump
logger.debug(object);

> 2018-10-16 00:17:17.011 DEBUG (test.js:34:21) *** OBJECT DUMP ***
>   TestClass {
>     "a": 1,
>     "b": 2,
>     "c": 3
>   }

// function dump
logger.debug(function);

> 2018-10-16 00:17:17.014 DEBUG (test.js:34:22) *** FUNCTION DUMP ***
>   function(a, b, c){return a+b+c};

Supports Log Rotation

You can specify when to rotate log and how many generations you want to keep easily.

// setup logger to rotate log file when file size exceed 100K
// And keep 3 generations on disk.
logger = require("jsclass-logger")({
  "toFile": true,
  "rotate": (file) => fs.statSync(file).size > 100000,
  "generation": 3
  });

Supports Timestamp Format Customize

You can customize timestamp format to meet your locale.

// setup logger to output customized timestamp
logger = require("jsclass-logger")({
  "ts": "DD/MM/YYYY hh:mm:ss"
});
logger.info("log message");

> 16/10/2018 00:17:17 INFO  (test.js:34:20) log message

Supports Stack Trace Dump

To print out stack trace, use "error()" or "trace()" to output log.

logger.error("log message");

> 16/10/2018 10:54:40 ERROR (test.js:32:20) log message
> at Context.<anonymous> (/Volumes/SDDrive/Google Drive/lib/jsclass-logger/test/test.js:32:20)
>     at callFn (/Volumes/SDDrive/Google Drive/lib/jsclass-logger/node_modules/mocha/lib/runnable.js:372:21)
>     at Test.Runnable.run (/Volumes/SDDrive/Google Drive/lib/jsclass-logger/node_modules/mocha/lib/runnable.js:364:7)

Supports Multi Log Level

Log Level for Debug Mode

"debug()" and "trace()" are log level for debug mode, so there will be no output when you don't set "debug: true" option to get logger instance.

Log Level For Production Mode

"info()", "warn()", "error()" are log lebel for production mode, so they will output log anytime.

Usage

API

Modules

Classes

Functions

jsclass-logger

Simple and easy to use logger.

Logger

Logger class.

Kind: global class

• Logger
  • .debug(msg)
  • .info(msg)
  • .warn(msg)
  • .trace(msg)
  • .error(msg)

logger.debug(msg)

Output log at DEBUG level, which is a debug level.

Kind: instance method of Logger

| Param | Type | Description | | --- | --- | --- | | msg | any | Log message. |

logger.info(msg)

Output log at INFO level, which is a production level.

Kind: instance method of Logger

| Param | Type | Description | | --- | --- | --- | | msg | any | Log message. |

logger.warn(msg)

Output log at WARN level, which is a production level.

Kind: instance method of Logger

| Param | Type | Description | | --- | --- | --- | | msg | any | Log message. |

logger.trace(msg)

Output log at TRACE level, which is a debug level.

Kind: instance method of Logger

| Param | Type | Description | | --- | --- | --- | | msg | any | Log message. |

logger.error(msg)

Output log at ERROR level, which is a production level.

Kind: instance method of Logger

| Param | Type | Description | | --- | --- | --- | | msg | any | Log message. |

getLogger(desc, mod) ⇒ Logger

Get logger instance. supprted options are as below. -debug: true / false -toFile: true / false -outDir: directory to output log file, by default it is "./log/" -rotate: function to check when to rotate log file, should return true / false -generation: log files to keep on disk -ts: timestamp format in YYYYMMDDhhmmsszzz format

Kind: global function
Returns: Logger - Logger instance

| Param | Type | Description | | --- | --- | --- | | desc | option | Logger option | | mod | option | modulename to output |