https://github.com/nicolo-ribaudo/legacy-decorators-migration-utility
:top: A command line utility to upgrade your JavaScript files from the legacy decorators proposal to the new one.
https://github.com/nicolo-ribaudo/legacy-decorators-migration-utility
babel decorators ecmascript javascript proposal tc39
Last synced: 12 days ago
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:top: A command line utility to upgrade your JavaScript files from the legacy decorators proposal to the new one.
- Host: GitHub
- URL: https://github.com/nicolo-ribaudo/legacy-decorators-migration-utility
- Owner: nicolo-ribaudo
- License: mit
- Created: 2018-09-19T22:33:48.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2018-09-21T22:04:44.000Z (over 6 years ago)
- Last Synced: 2025-03-25T12:51:03.139Z (29 days ago)
- Topics: babel, decorators, ecmascript, javascript, proposal, tc39
- Language: JavaScript
- Homepage:
- Size: 71.3 KB
- Stars: 22
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Legacy decorators migration utility
This repository contains a series of packages that make it easier to migrate
from legacy decorators to the new version of the proposal. This utils are
mainly meant for decorators consumers, but the `decorators-compat` package could
also be used by decorators authors.
This utilities only work with class decorators: since object decorators aren't
included in the decorators proposal anymore, you will need to manually remove
them.
TL;DR:
```
$ npx wrap-legacy-decorators path/to/file.js --decorators-before-export
```
## Packages
### `wrap-legacy-decorators`
This package contains a command line utility to upgrade a JavaScript file to the
current decorators semantics. It is meant to be either used with `npx` or
installed globally:
```
$ npx wrap-legacy-decorators file.js
OR:
$ npm install --global wrap-legacy-decorators
$ wrap-legacy-decorators file.js
OR:
$ yarn global add wrap-legacy-decorators
$ wrap-legacy-decorators file.js
```
It also works with multiple files:
```
$ npx wrap-legacy-decorators foo.js bar.js
OR:
$ npx wrap-legacy-decorators src/**/*.js
```
#### Options
| **Option** | **Description** |
|----------------------|---------------------------|
| `-h, --help` | Show usage information. |
| `-v, --version` | Show the utility version. |
| `--decorators-before-export` or `--decorators-after-export` | (*Required*) Sets the position of decorators relative to the `export` keyword. |
| `--external-helpers` | Use the `decorators-compat` package instead of inserting the helper inline in each file. |
| `--write` | Update the file in-place, instead of printing the modified code to the console. |
### `decorators-compat`
This module exports a function which wraps any legacy decorator, making it compatible with the new proposal. If you are using the `wrap-legacy-decorators` command with the `--external-helpers` flag, you must add this package to your dependencies:
```
$ npm install --save decorators-compat
OR:
$ yarn add decorators-compat
```
#### Usage
```js
// If you where using a legacy decorator like this:
@legacyDecorator1
@legacyDecorator2
class Foo {}
// ... when upgrading to the new proposal it should become something like this:
import decoratorsCompat from "decorators-compat";
@decoratorsCompat([legacyDecorator1, legacyDecorator2])
class Foo {}
```
#### Caveats
Since legacy decorators are applyed to the finished class rather then to an intermediate representation, they always run *after* modern decorators. For this reason, it is highly reccomended to write the legacy decorators you are using *before* the modern decorators.
### `babel-plugin-wrap-legacy-decorators`
This Babel plugin is used internally by the `wrap-legacy-decorators` command line utility. It accepts two options: `decoratorsBeforeExport: boolean` and `externalHelpers: boolean`.