feat(props): Add function to drop all keys whose values are undefined…

… in a… (#12)

* feat(): Add function to drop all keys whose values are undefined in an object

Add function to drop all keys whose values are undefined in an object

* refactor(): Rename function

- Rename function `removeEmptyKeys` to `removeEmptyProperties` as
  requested by author.

- Make other changes to accommodate this change.

* refactor(): Add `removeEmptyProperties` to package's exports

* test: Update top-level export test

Update top-level exports test to recognize new function `removeEmptyProperties`.

* docs: Update documentation to include new function `removeEmptyProperties`

.all-contributorsrc

@@ -46,6 +46,18 @@
       "contributions": [
         "doc"
       ]
+    },
+    {
+      "login": "huy-nguyen",
+      "name": "Huy Nguyen",
+      "avatar_url": "https://avatars.githubusercontent.com/u/7352279?v=3",
+      "profile": "http://www.huy-nguyen.com/",
+      "contributions": [
+        "code",
+        "doc",
+        "example",
+        "test"
+      ]
     }
   ]
 }

README.md

@@ -9,7 +9,7 @@ Utilities to help your webpack config be easier to read
 [![downloads][downloads-badge]][npm-stat]
 [![MIT License][license-badge]][LICENSE]
 
-[![All Contributors](https://img.shields.io/badge/all_contributors-4-orange.svg?style=flat-square)](#contributors)
+[![All Contributors](https://img.shields.io/badge/all_contributors-5-orange.svg?style=flat-square)](#contributors)
 [![PRs Welcome][prs-badge]][prs]
 [![Donate][donate-badge]][donate]
 [![Code of Conduct][coc-badge]][coc]
@@ -48,12 +48,27 @@ It is expected that you use this in your `webpack.config.js` file.
 
 ```javascript
 const webpack = require('webpack')
-const {getIfUtils, removeEmpty} = require('webpack-config-utils')
+const {getIfUtils, removeEmpty, removeEmptyProperties} = require('webpack-config-utils')
 
 const {ifProduction} = getIfUtils(process.env.NODE_ENV)
 
 module.exports = {
   // ... your config
+  entry: removeEmptyProperties({
+     app: ifProd('./indexWithoutCSS', './indexWithCSS'),
+     css: ifProd('./style.scss')
+  }),
+  module: {
+    loaders: [
+      removeEmptyProperties({
+        test: /\.scss$/,
+        loader: ifProd(ExtractTextPlugin.extract({
+          loader: ['css-loader', 'sass-loader']
+        })),
+        loaders: ifNotProd(['style-loader', 'css-loader', 'sass-loader'])
+      })
+    ]
+  },
   plugins: removeEmpty([
     ifProduction(new webpack.optimize.DedupePlugin()),
     ifProduction(new webpack.LoaderOptionsPlugin({
@@ -126,8 +141,8 @@ a few another helpful utility: [`webpack-combine-loaders`](https://www.npmjs.com
 Thanks goes to these people ([emoji key][emojis]):
 
 <!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
-| [<img src="https://avatars.githubusercontent.com/u/1500684?v=3" width="100px;"/><br /><sub>Kent C. Dodds</sub>](https://kentcdodds.com)<br />[💻](https://github.com/kentcdodds/webpack-config-utils/commits?author=kentcdodds) [📖](https://github.com/kentcdodds/webpack-config-utils/commits?author=kentcdodds) 💡 🚇 [⚠️](https://github.com/kentcdodds/webpack-config-utils/commits?author=kentcdodds) | [<img src="https://avatars.githubusercontent.com/u/284515?v=3" width="100px;"/><br /><sub>Breno Calazans</sub>](https://twitter.com/breno_calazans)<br />💡 | [<img src="https://avatars.githubusercontent.com/u/363583?v=3" width="100px;"/><br /><sub>Tamara Temple</sub>](http://tamouse.org)<br />[📖](https://github.com/kentcdodds/webpack-config-utils/commits?author=tamouse) | [<img src="https://avatars.githubusercontent.com/u/7907232?v=3" width="100px;"/><br /><sub>Ben Halverson</sub>](benhalverson.me)<br /> |
-| :---: | :---: | :---: | :---: |
+| [<img src="https://avatars.githubusercontent.com/u/1500684?v=3" width="100px;"/><br /><sub>Kent C. Dodds</sub>](https://kentcdodds.com)<br />[💻](https://github.com/kentcdodds/webpack-config-utils/commits?author=kentcdodds) [📖](https://github.com/kentcdodds/webpack-config-utils/commits?author=kentcdodds) 💡 🚇 [⚠️](https://github.com/kentcdodds/webpack-config-utils/commits?author=kentcdodds) | [<img src="https://avatars.githubusercontent.com/u/284515?v=3" width="100px;"/><br /><sub>Breno Calazans</sub>](https://twitter.com/breno_calazans)<br />💡 | [<img src="https://avatars.githubusercontent.com/u/363583?v=3" width="100px;"/><br /><sub>Tamara Temple</sub>](http://tamouse.org)<br />[📖](https://github.com/kentcdodds/webpack-config-utils/commits?author=tamouse) | [<img src="https://avatars.githubusercontent.com/u/7907232?v=3" width="100px;"/><br /><sub>Ben Halverson</sub>](benhalverson.me)<br />[📖](https://github.com/kentcdodds/webpack-config-utils/commits?author=benhalverson) | [<img src="https://avatars.githubusercontent.com/u/7352279?v=3" width="100px;"/><br /><sub>Huy Nguyen</sub>](http://www.huy-nguyen.com/)<br />[💻](https://github.com/kentcdodds/webpack-config-utils/commits?author=huy-nguyen) [📖](https://github.com/kentcdodds/webpack-config-utils/commits?author=huy-nguyen) 💡 [⚠️](https://github.com/kentcdodds/webpack-config-utils/commits?author=huy-nguyen) |
+| :---: | :---: | :---: | :---: | :---: |
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 This project follows the [all-contributors][all-contributors] specification. Contributions of any kind welcome!

src/index.js

@@ -6,3 +6,4 @@ export {default as combineLoaders} from 'webpack-combine-loaders'
 export * from './prop-if'
 export * from './remove-empty'
 export * from './get-if-utils'
+export * from './remove-empty-properties'

src/index.test.js

@@ -8,6 +8,7 @@ test('exports all the things we care about', t => {
     'combineLoaders',
     'propIf', 'propIfNot',
     'removeEmpty', 'getIfUtils',
+    'removeEmptyProperties',
   ]
   const diff = difference(allExports, expectedExports)
   t.deepEqual(diff, [])

src/remove-empty-properties.js

@@ -0,0 +1,28 @@
+export {
+  removeEmptyProperties,
+}
+/**
+ * Accepts an object and removes all keys whose values are undefined.
+ * @example
+ * // Use case: move CSS into separate file for production (with `extract-text-webpack-plugin`)
+ * // but not in development:
+ * {
+ *  // other webpack configs
+ *  entry: removeEmptyProperties({
+ *    app: ifProd('./indexWithoutCSS', './indexWithCSS'),
+ *    css: ifNotProd('./style.css')
+ *  })
+ * {
+ * @param {object} object The object to remove keys from
+ * @returns {object} The resulting object
+ */
+function removeEmptyProperties(object) {
+  const output = {}
+  Object.keys(object).forEach(key => {
+    const value = object[key]
+    if (typeof value !== 'undefined') {
+      output[key] = value
+    }
+  })
+  return output
+}

src/remove-empty-properties.test.js

@@ -0,0 +1,9 @@
+import test from 'ava'
+import {removeEmptyProperties} from './remove-empty-properties'
+
+test('removeEmptyProperties should remove keys whose values are `undefined` out of an object', t => {
+  t.deepEqual(
+    removeEmptyProperties({a: 1, b: 'b', c: undefined, d: null}),
+    {a: 1, b: 'b', d: null}
+  )
+})