https://github.com/ember-cli/babel-plugin-feature-flags

A babel transform for managing feature flags
https://github.com/ember-cli/babel-plugin-feature-flags

babel-plugin

Last synced: 3 months ago
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A babel transform for managing feature flags

• Host: GitHub
• URL: https://github.com/ember-cli/babel-plugin-feature-flags
• Owner: ember-cli
• Created: 2015-06-06T18:53:14.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2021-07-28T03:32:32.000Z (over 3 years ago)
• Last Synced: 2024-07-16T15:41:30.411Z (4 months ago)
• Topics: babel-plugin
• Language: JavaScript
• Size: 49.8 KB
• Stars: 57
• Watchers: 10
• Forks: 6
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Code of conduct: CODE_OF_CONDUCT.md

Awesome Lists containing this project

• awesome-babel - feature-flags - Helper for managing application feature flags. (Plugins / General Plugins)

README

        
# babel-plugin-feature-flags

[![Build Status](https://travis-ci.org/ember-cli/babel-plugin-feature-flags.svg?branch=master)](https://travis-ci.org/ember-cli/babel-plugin-feature-flags)

*This plugin is for Babel 6. If you need to support Babel 5 use the 0.2.x releases.*

A babel plugin that implements feature flags for enabling and disabling features. This plugin is intended to be followed by a dead code elimination pass (Uglify, babel-plugin-dead-code-elimination, etc.) to remove any unreachable code.

Feature flags are implemented by looking for call expressions like `isEnabled('my-feature')` and checking if the feature is enabled/disabled/disabled in a feature map that is passed through the plugin options. If the feature is known to be enabled or disabled then the call expression is replace with a boolean literal (`true` or `false` respectively). If the feature is dynamic, than the call expression is left alone.

## Example

Given the `.babelrc`

```json

{

  "plugins": [["feature-flags", {

    "import": {

        "module": "my-features"

    },

    "features": {

        "new-feature": "disabled"

    }

  }]]

}

```

the JavaScript file

```js

import isEnabled from 'my-features';

if (isEnabled('new-feature')) {

  // code

}

```

will be transformed to

```js

import isEnabled from 'my-features';

if (false) {

  // code

}

```

## Configuration

Here are the options that you can pass to the babel plugin.

- `options.import.module` [`String`]: The name of the module that the feature function is imported from.

- `options.import.name` [`String` (Optional)]: The name of the export that the feature function is imported from. Defaults to `"default"`.

- `options.features` [`Map(String -> 'enabled' | 'disabled' | 'dynamic')`]: An object whose keys are the names of features and whose values determine whether the feature is enabled/disabled/dynamic.