Debug Plus

debug-plus is a drop-in replacement wrapper for the superb debug node module and adds semantic sugar for console-style logging of various types of messages such as log, warn, error, or even dir.

Additional helper methods such as stringify, inspect, and timestamp are also available to help the debugging process.

Installation

$ npm install debug-plus

Usage

As with the standard debug module you can simply invoke the exported debug-plus function to generate your debug function, passing it a name which will determine if a noop function is returned, or a decorated console.log, so all of the console format string goodies you're used to work fine. Additionally, debug-plus exposes semantic console-style functions on top of the standard debug method. A unique color is selected per-function for visibility.

Example app.coffee:

debug = require("debug-plus") "app"
http = require "http"
name = "Awesome App"

# Standard `debug` style logging with String substitution
debug "booting %s", name

http.createServer (p_request, p_response) ->
	# `console.log` style logging
	debug.log "#{p_request.method} #{p_request.url}"

	# `console.warn` style logging
	if p_request.url is "/warn"
		debug.warn "#{p_request.url} is deprecated"

	# `console.error` style logging
	else if p_request.url is "/stringError"
		debug.error "#{p_request.url} is unsupported"

	# `console.error` style logging with a stack trace
	else if p_request.url is "/error"
		debug.error new Error "#{p_request.url} is unsopported"

	p_response.end "Click!\n"

require "./peon"

Example peon.coffee:

	debug = require("debug-plus") "peon"

	setInterval ->
		debug.log "Zug zug!"
	, 3000

Configuration

process.env.DEBUG

The DEBUG environment variable is then used to enable these based on space or comma-delimited names.

When a default DEBUG environment variable is unspecified debug-plus will default to *:warn(:[0-9]+)?,*:error(:[0-9]+)? to display warnings and errors.

node-config

debug-plus supports the node-config module for specifying project-level and environment-level configurations.

Example ./config/development.coffee:

module.exports =
	"debug-plus":
		default: "*" # Designate the namespace to log if `process.env.DEBUG` is undefined - Default: "*:warn(:[0-9]+)?,*:error(:[0-9]+)?"
		showProcess: false # Append the process id to the log messages (useful when working with clustering) - Default: false
		breakOnError: true # If working with a debugger (such as `node-inspector`) you can have debug-plus automatically break on a call to `debug.error()` - Default: false

Example ./config/production.coffee:

module.exports =
	"debug-plus":
		default: "*:warn(:[0-9]+)?,*:error(:[0-9]+)?" # Designate the namespace to log if `process.env.DEBUG` is undefined - Default: "*:warn(:[0-9]+)?,*:error(:[0-9]+)?"
		showProcess: true # Append the process id to the log messages (useful when working with clustering) - Default: false
		breakOnError: false # If working with a debugger (such as `node-inspector`) you can have debug-plus automatically break on a call to `debug.error()` - Default: false

Conventions

If you're using this in one or more of your libraries, you should use the name of your library so that developers may toggle debugging as desired without guessing names. If you have more than one debuggers you should prefix them with your library name and use ":" to separate features. For example "bodyParser" from Connect would then be "connect:bodyParser".

Wildcards

The * character may be used as a wildcard. Suppose for example your library has debuggers named "connect:bodyParser", "connect:compress", "connect:session", instead of listing all three with DEBUG=connect:bodyParser,connect.compress,connect:session, you may simply do DEBUG=connect:*, or to run everything using this module simply use DEBUG=*.

You can also exclude specific debuggers by prefixing them with a "-" character. For example, DEBUG=*,-connect:* would include all debuggers except those starting with "connect:".

Millisecond diff

When actively developing an application it can be useful to see when the time spent between one debug() call and the next. Suppose for example you invoke debug() before requesting a resource, and after as well, the "+NNNms" will show you how much time was spent between calls.

When stdout is not a TTY, Date#toUTCString() is used, making it more useful for logging the debug information as shown below:

Debug Plus Author

• Elliot Chong

Debug Authors

• TJ Holowaychuk
• Nathan Rajlich

Debug & Debug Plus License

(The MIT License)

Original work Copyright (c) 2014 TJ Holowaychuk <[email protected]>
Modified work Copyright (c) 2014 Elliot Chong <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.