About loggedmessage

loggedmessage is a simple but flexible console logging library written in JavaScript with no dependencies. loggedmessage comes with common-sense builtin functions and defaults, and works right out of the box.

The package provides you with functions logm(), infom() and timem() to log messages to the console with standard formatting, as well as functions errm(), warnm() and throwm() for error handling. Also included is printm(), a simple wrapper for console.log() that returns an array of the arguments it's given.

Install

Install loggedmessage via NPM:

$ npm i loggedmessage

Basic Usage

Import:

Import the library in your code:

import loggedmessage from "loggedmessage";
//  or
import { logm, errm, warnm, infom, timem, printm, throwm } from "loggedmessage";

loggedmessage must be imported as an ES6 module.

Logging:

To log to the console:

import lm from "loggedmessage";

lm.logm("This is a log message");
lm.errm("Failed to connect to server");
lm.warnm("Request for /:user failed without authorization");
lm.infom("Server listening on port 3000");
lm.timem("Received a GET request for /");
lm.printm("A regular console.log() statement");
lm.throwm("Invalid configuration file");

Output:

LOGM: This is a log message
ERRM: Failed to connect to server
WARNM: Request for /:user failed without authorization
INFOM: Server listening on port 3000
12/31/1999, 12:35:00 PM: Received a GET request for /
A regular console.log() statement
THROWM: Invalid configuration file
<stackTrace>
        throw new Error(`${toString(errPrefix, errSeparator)} ${checkObject(errMessage)}`);
              ^
Error: THROWM: Invalid configuration file
    at <stackTrace>

Configuration

If dotenv is installed in the project, message defaults can be configured using a .env file:

### Prefix abbreviation
### (leave commented to not print a prefix abbreviation)
PREFIX_ABR = "APP"

### Separator between abbreviation and prefix
### (leave commented to use the default separator)
PREFIX_SEPARATOR = "-"

### Default message type prefixes
### (leave commented to use the default prefixes)
LOGM_PREFIX   = "LOG"
ERRM_PREFIX   = "ERROR"
THROWM_PREFIX = "ERROR-THROWN"
WARNM_PREFIX  = "WARNING"
INFOM_PREFIX  = "INFORMATION"

### Default separator between the prefix and message
### (leave commented to use the default separator)
MESSAGE_SEPARATOR = " ::"

### Default text for undefined messages
### (leave commented to use the default text)
LOG_MESSAGE   = "a new message was logged"
ERROR_MESSAGE = "a new error has occurred"
WARN_MESSAGE  = "a new warning was logged"

### Time message locale
### (leave commented to use "en-US")
### ex.: "en-US", "en-GB", "ko-KR", "ar-EG", "ja-JP-u-ca-japanese", etc.
TIMEM_LOCALE = "en-GB"

If dotenv is not installed, loggedmessage will use the builtin defaults.

Documentation

logm()

Log a message to the console.

Parameters

• message any — the message content. (optional, default null)
• prefix string — the message prefix text. (optional, default null)
• separator string — the separator string between the prefix and message text. (optional, default null)

Examples

Code:

logm("logged message", "LOG", " |");

Output:

LOG | logged message

Returns string — the full message string as {prefix}{separator} {message}.

errm()

Log an error to the console with the desired message.

Parameters

• message any — the error message content. (optional, default null)
• err Error — a target error to print to print. (optional, default null)
• prefix string — the error message prefix text. (optional, default null)
• separator string — the separator string between the prefix and error message text. (optional, default null)

Examples

Code:

errm("error message", new Error("error text"), "ERROR", " |");

Output:

ERROR | error message 
 Error: error text
    at <stackTrace>

Returns string — the full error message string as {prefix}{separator} {message}.

warnm()

Log a warning message/error to the console with the desired message.

Parameters

• message any — the warning message content. (optional, default null)
• err Error — a target error to print. (optional, default null)
• separator string — the separator string between the prefix and warning message text. (optional, default null)

Examples

Code:

warnm("warning message", new Error("error text"), " |");

Output:

WARNM | warning message 
 Error: error text
    at <stackTrace>

Returns string — the full warning message string as {prefix}{separator} {message}.

infom()

Log an info message/error to the console with the desired message.

Parameters

• message any — the info message content. (optional, default null)
• err Error — a target error to print. (optional, default null)
• separator string — the separator string between the prefix and info message text. (optional, default null)

Examples

Code:

infom("information message", undefined, " |");

Output:

INFOM | information message

Returns string — the full info message string as {prefix}{separator} {message}.

timem()

Log a message/error to the console with the desired message and the current time.

Parameters

• message any — the message content. (optional, default null)
• err Error — a target error to print. (optional, default null)
• separator string — the separator string between the prefix and message text. (optional, default null)

Examples

Code:

timem("time-logged message", undefined, " |");

Output:

12/31/1999, 12:35:00 PM | time-logged message

Returns string — the full message string as {prefix}{separator} {message}.

printm()

Print a message to the console (wrapper for console.log()).

Parameters

• message any — the message content.
• optionalParams ...any — additional values or objects for output.

Examples

Code:

printm("printed message", "& additional output");

Output:

printed message & additional output

Returns Array — an array of the arguments passed.

throwm()

Throw an error with the desired message.

Parameters

• message any — the error message content. (optional, default null)
• err Error — a target error to print. (optional, default null)
• prefix string — the error message prefix text. (optional, default null)
• separator string — the separator string between the prefix and error message text. (optional, default null)

Examples

Code:

throwm("thrown error message", new Error("error text"), "ERROR", " |");

Output:

ERROR | thrown error message
<stackTrace>
throwm("thrown error message", new Error("error text"), "ERROR", " |");
                               ^
Error: error text
    at <stackTrace>

Returns string — the full error message string as {prefix}{separator} {message}.