deprecation

What is deprecation?

The `deprecation` npm package is designed to help developers manage and signal deprecations within their codebase. It provides a structured way to mark certain functionalities as deprecated, issue warnings, and guide users towards alternatives or updated practices. This can be particularly useful in libraries or applications undergoing gradual upgrades or changes, ensuring backward compatibility while encouraging the adoption of new features or methods.

What are deprecation's main functionalities?

Emitting Deprecation Warnings

This feature allows developers to emit deprecation warnings with a unique ID and a message guiding users towards an alternative method or practice. The code sample demonstrates how to create a new `Deprecation` instance associated with a specific package and issue a warning about a deprecated method.

"use strict";
const Deprecation = require('deprecation');

const deprecation = new Deprecation('@mycompany/mypackage');

deprecation.warn('deprecated-method', 'The `deprecatedMethod()` is deprecated and will be removed in the next major release. Use `newMethod()` instead.');

Other packages similar to deprecation

depd

The `depd` package is similar to `deprecation` in that it provides a way to declare deprecations and issue warnings in Node.js applications. However, `depd` focuses more on a minimalistic approach and is widely used for expressing deprecations in middleware or frameworks. It automatically handles the generation of detailed deprecation messages, including the stack trace to the deprecated call, which differs from `deprecation`'s more manual and message-centric approach.

warning

The `warning` package is another tool for managing warnings in JavaScript applications, not limited to deprecations. It allows developers to print warning messages to the console if a condition fails, which can be used for deprecations but also for other types of warnings. Compared to `deprecation`, `warning` is more general-purpose and does not specifically focus on package or method deprecations.

README

deprecation

Log a deprecation message with stack

Usage

Browsers	Load deprecation directly from cdn.pika.dev <script type="module"> import { Deprecation } from "https://cdn.pika.dev/deprecation/v2"; </script>
Node	Install with npm install deprecation const { Deprecation } = require("deprecation"); // or: import { Deprecation } from "deprecation";

function foo() {
  bar();
}

function bar() {
  baz();
}

function baz() {
  console.warn(new Deprecation("[my-lib] foo() is deprecated, use bar()"));
}

foo();
// { Deprecation: [my-lib] foo() is deprecated, use bar()
//     at baz (/path/to/file.js:12:15)
//     at bar (/path/to/file.js:8:3)
//     at foo (/path/to/file.js:4:3)

To log a deprecation message only once, you can use the once module.

const Deprecation = require("deprecation");
const once = require("once");

const deprecateFoo = once(console.warn);

function foo() {
  deprecateFoo(new Deprecation("[my-lib] foo() is deprecated, use bar()"));
}

foo();
foo(); // logs nothing

License

ISC