What is depd?
The depd package is a deprecation helper for Node.js. It allows developers to mark functions, properties, and other JavaScript features as deprecated and to issue warning messages when they are used. This can be useful for library authors who want to make changes or remove features without breaking existing code that depends on their libraries.
What are depd's main functionalities?
Deprecate functions
This feature allows you to deprecate a function by wrapping it with a deprecation warning. When the function is called, it will log a deprecation message to the console.
var deprecate = require('depd')('my-module-name');
function oldFunction() {
deprecate('oldFunction is deprecated, use newFunction instead.');
// old function code
}
Deprecate property access
This feature allows you to deprecate access to an object property. When the property is accessed, it will log a deprecation message to the console.
var deprecate = require('depd')('my-module-name');
var obj = {};
Object.defineProperty(obj, 'oldProperty', {
get: function () {
deprecate('oldProperty is deprecated, use newProperty instead.');
return 'some value';
}
});
Customize deprecation messages
This feature allows you to customize the deprecation message for a property to provide additional information or instructions.
var deprecate = require('depd')('my-module-name');
deprecate.property(obj, 'oldProperty', 'oldProperty is deprecated and will be removed in the next major release.');
Other packages similar to depd
deprecate
The deprecate package is similar to depd in that it allows you to mark functions as deprecated. However, it is more lightweight and does not provide the ability to deprecate properties or customize messages to the same extent as depd.
util-deprecate
This package is a Node.js utility for marking deprecated APIs. It is similar to depd but is specifically designed to work with Node.js's built-in 'util' module. It provides a straightforward way to deprecate functions but does not support property deprecation.
depd
Deprecate all the things
With great modules comes great responsibility; mark things deprecated!
Install
$ npm install depd
API
var depd = require('depd')
var deprecate = depd('my-module')
This library allows you to display deprecation messages to your users.
This library goes above and beyond with deprecation warnings by
introspecting the call stack (but only the bits that it is interested
in).
Instead of just warning on the first invocation of a deprecated
function and never again, this module will warn on the first invocation
of a deprecated function per unique call site, making it ideal to alert
users of all deprecated uses across the code base, rather than just
whatever happens to execute first.
The deprecation warnings from this module also include the file and line
information for the call into the module that the deprecated function was
in.
depd(namespace)
Create a new deprecate function that uses the given namespace name in the
messages and will display the call site prior to the stack entering the
file this function was called from. It is highly suggested you use the
name of your module as the namespace.
deprecate(message)
Call this function from deprecated code to display a deprecation message.
This message will appear once per unique caller site. Caller site is the
first call site in the stack in a different file from the caller of this
function.
Examples
This will display a deprecated message about "oldfunction" being deprecated
from "my-module" on STDERR.
var deprecate = require('depd')('my-cool-module')
exports.oldfunction = function () {
deprecate('oldfunction')
}
exports.weirdfunction = function () {
if (arguments.length < 2) {
deprecate('weirdfunction args < 2')
}
}
Then a user calls mymodule.oldfunction()
and sees (in the given colors,
similar colors and layout to the debug
module):
bright cyan bright yellow
| | grey cyan
| | | |
▼ ▼ ▼ ▼
my-cool-module deprecated oldfunction [eval]-wrapper:6:22
▲ ▲ ▲ ▲
| | | |
namespace | | location of mycoolmod.oldfunction() call
| deprecation message
the word "deprecated"
If the user redirects their STDERR to a file or somewhere that does not support
colors, they see (similar layout to the debug
module):
Sun, 15 Jun 2014 05:21:37 GMT my-cool-module deprecated oldfunction at [eval]-wrapper:6:22
▲ ▲ ▲ ▲ ▲
| | | | |
timestamp of message namespace | | location of mycoolmod.oldfunction() call
| deprecation message
the word "deprecated"
License
The MIT License (MIT)
Copyright (c) 2014 Douglas Christopher Wilson
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.