*: format, refactor, and update

- Change code style from [StandardJS](https://standardjs.com/) to [Prettier](https://prettier.io/)-like style.
- Format all the code.
- Use [ESLint](https://eslint.org/) for linting JavaScript code.
- Add `package-lock.json` file to `.gitignore`.
- Refactor code and tests.
- Add `format` NPM script to format code (`npm run format`).
- Update dependencies to their latest version.

.eslintrc.json

@@ -0,0 +1,17 @@
+{
+  "env": {
+    "commonjs": true,
+    "es2021": true,
+    "node": true
+  },
+  "extends": "eslint:recommended",
+  "parserOptions": {
+    "ecmaVersion": "latest"
+  },
+  "rules": {
+    "indent": ["error", 2],
+    "linebreak-style": ["error", "unix"],
+    "quotes": ["error", "single"],
+    "semi": ["error", "always"]
+  }
+}

.gitignore

@@ -1 +1,2 @@
-node_modules
+node_modules/
+package-lock.json

.prettierrc.json

@@ -0,0 +1,4 @@
+{
+  "singleQuote": true,
+  "trailingComma": "none"
+}

.travis.yml

@@ -1,5 +1,6 @@
 language: node_js
 node_js:
-  - "10"
-  - "12"
-  - "14"
+  - '10'
+  - '12'
+  - '14'
+  - '16'

index.js

@@ -1,59 +1,61 @@
-const getPixels = require('get-pixels')
-const getRgbaPalette = require('get-rgba-palette')
-const chroma = require('chroma-js')
-const getSvgColors = require('get-svg-colors')
-const pify = require('pify')
+const getPixels = require('get-pixels');
+const getRgbaPalette = require('get-rgba-palette');
+const chroma = require('chroma-js');
+const getSvgColors = require('get-svg-colors');
+const pify = require('pify');
 
 const patterns = {
-  image: /\.(gif|jpg|png|svg)$/i,
-  raster: /\.(gif|jpg|png)$/i,
-  svg: /svg$/i
-}
+  image: /\.(?:gif|jpg|png|svg)$/i,
+  raster: /\.(?:gif|jpg|png)$/i,
+  svg: /\.svg$/i
+};
 
-function colorPalette (input, options, callback) {
+function colorPalette(input, options, callback) {
   if (typeof options === 'function') {
-    callback = options
+    callback = options;
     options = {
       type: undefined,
       count: 5
-    }
-  } else if (typeof options === 'string') {
+    };
+  } else if (typeof options === 'string')
     options = {
       type: options,
       count: 5
-    }
-  }
+    };
 
   // SVG
-  if (!Buffer.isBuffer(input)) {
-    if (input.match(patterns.svg)) {
-      return callback(null, getSvgColors(input, { flat: true }))
-    }
-  } else if (options.type === 'image/svg+xml') {
-    return callback(null, getSvgColors(input, { flat: true }))
-  }
+  if (
+    (!Buffer.isBuffer(input) && patterns.svg.test(input)) ||
+    options.type === 'image/svg+xml'
+  )
+    return callback(null, getSvgColors(input, { flat: true }));
 
   // PNG, GIF, JPG
-  return paletteFromBitmap(input, options, callback)
+  return paletteFromBitmap(input, options, callback);
 }
 
-function paletteFromBitmap (filename, options, callback) {
-  if (!callback) {
-    callback = options
+function paletteFromBitmap(filename, options, callback) {
+  if (callback == undefined) {
+    callback = options;
     options = {
       type: undefined,
       count: 5
-    }
+    };
   }
 
-  getPixels(filename, options.type, function (err, pixels) {
-    if (err) return callback(err)
-    const palette = getRgbaPalette(pixels.data, options.count).map(function (rgba) {
-      return chroma(rgba)
-    })
+  getPixels(filename, options.type, (err, pixels) => {
+    if (err != undefined) {
+      callback(err);
+
+      return;
+    }
+
+    const palette = getRgbaPalette(pixels.data, options.count).map((rgba) =>
+      chroma(rgba)
+    );
 
-    return callback(null, palette)
-  })
+    callback(null, palette);
+  });
 }
 
-module.exports = pify(colorPalette)
+module.exports = pify(colorPalette);

package.json

@@ -4,8 +4,9 @@
   "description": "Extract colors from images. Supports GIF, JPG, PNG, and even SVG!",
   "main": "index.js",
   "scripts": {
-    "test": "mocha && standard && standard-markdown *.md",
-    "lint": "standard"
+    "test": "mocha && eslint .",
+    "lint": "eslint .",
+    "format": "prettier -w ."
   },
   "repository": "https://github.com/colorjs/get-image-colors",
   "keywords": [
@@ -23,20 +24,15 @@
   "author": "zeke",
   "license": "MIT",
   "devDependencies": {
-    "mocha": "^8.1.1",
-    "standard": "^14.3.4",
-    "standard-markdown": "^6.0.0"
+    "eslint": "^8.16.0",
+    "mocha": "^10.0.0",
+    "prettier": "^2.6.2"
   },
   "dependencies": {
-    "chroma-js": "^2.1.0",
-    "get-pixels": "^3.3.2",
+    "chroma-js": "^2.4.2",
+    "get-pixels": "^3.3.3",
     "get-rgba-palette": "^2.0.1",
     "get-svg-colors": "^2.0.0",
     "pify": "^5.0.0"
-  },
-  "standard": {
-    "env": {
-      "mocha": true
-    }
   }
 }

readme.md

@@ -7,84 +7,91 @@ Extract colors from images. Supports GIF, JPG, PNG, and even SVG!
 ## Installation
 
 ```sh
-npm install get-image-colors --save
+npm install get-image-colors
 ```
 
 This package is intended for use in node environments. It won't work in a browser because it has node-specific dependencies.
 
-**Note:** when installing with webpack, if you get the error 
+**Note:** when installing with webpack, if you get the error
+
 ```
-Can't resolve 'fs' in '/node_modules/get-svg-colors' 
+Can't resolve 'fs' in '/node_modules/get-svg-colors'
 ```
+
 as per an [open issue in webpack-contrib](https://github.com/webpack-contrib/css-loader/issues/447), you will need to add `node: { fs: 'empty' }` to your `webpack.base.config`:
-```
+
+```js
 module.exports = {
-    ... ,
+    ...,
     node: { fs: 'empty' }
-}
+};
 ```
 
 ## Usage
 
 ```js
-const path = require('path')
-const getColors = require('get-image-colors')
+const path = require('path');
+const getColors = require('get-image-colors');
 
-getColors(path.join(__dirname, 'double-rainbow.png')).then(colors => {
+getColors(path.join(__dirname, 'double-rainbow.png')).then((colors) => {
   // `colors` is an array of color objects
-})
+});
 ```
 
 You can also use a buffer as an input source.
+
 ```js
-const fs = require('fs')
-const buffer = fs.readFileSync(path.join(__dirname, 'double-rainbow.gif'))
-const getColors = require('get-image-colors')
+const fs = require('fs');
+const buffer = fs.readFileSync(path.join(__dirname, 'double-rainbow.gif'));
+const getColors = require('get-image-colors');
 
-getColors(buffer, 'image/gif').then(colors => {
+getColors(buffer, 'image/gif').then((colors) => {
   // `colors` is an array of color objects
-})
+});
 ```
 
-`colors` is an array of [chroma.js](http://gka.github.io/chroma.js) color objects. chroma.js objects have methods that lets you pick the color format you want (RGB hex, HSL, etc), and give you access to powerful color manipulation features:
+`colors` is an array of [chroma.js][] color objects. chroma.js objects have methods that lets you pick the color format you want (RGB hex, HSL, etc), and give you access to powerful color manipulation features:
 
 ```js
-colors.map(color => color.hex())
+colors.map((color) => color.hex());
 // => ['#FFFFFF', '#123123', '#F0F0F0']
 
-colors[0].alpha(0.5).css()
-// => 'rgb(0,128,128)''
+colors[0].alpha(0.5).css();
+// => 'rgb(0,128,128)'
 ```
 
 If you don't like promises, you can use node-style callbacks too:
 
 ```js
-getColors(filename, function (err, colors) {
-  if (err) throw err
+getColors(filename, (err, colors) => {
+  if (err) throw err;
   // ...
-})
+});
 ```
 
-The default number of colors returned is 5.  You can specify a different number of colors by passing an options object into the call to getColors:
+The default number of colors returned is 5. You can specify a different number of colors by passing an options object into the call to getColors:
 
 ```js
-const path = require('path')
-const getColors = require('get-image-colors')
+const path = require('path');
+const getColors = require('get-image-colors');
 
 const options = {
   count: 10,
   type: 'image/png'
-}
-getColors(path.join(__dirname, 'double-rainbow.png'), options).then(colors => {
-  // `colors` is an array of 10 color objects
-})
+};
+
+getColors(path.join(__dirname, 'double-rainbow.png'), options).then(
+  (colors) => {
+    // `colors` is an array of 10 color objects
+  }
+);
 ```
 
 ## How it Works
 
-`get-image-colors` uses [get-pixels](http://npm.im/get-pixels) to create a pixel array, then extracts a color palette with [get-rgba-palette](http://npm.im/get-rgba-palette), which uses [quantize](http://npm.im/quantize) under the hood.
+`get-image-colors` uses [get-pixels][] to create a pixel array, then extracts a color palette with [get-rgba-palette][], which uses [quantize](http://npmjs.com/package/quantize) under the hood.
 
-Colors are converted from [get-rgba-palette's flat array format](https://github.com/mattdesl/get-rgba-palette#palettepixels-count-quality-filter) into [chroma.js color instances](http://gka.github.io/chroma.js/).
+Colors are converted from [get-rgba-palette's flat array format](https://github.com/mattdesl/get-rgba-palette#palettepixels-count-quality-filter) into [chroma.js color instances][chroma.js].
 
 ## Tests
 
@@ -95,15 +102,21 @@ npm test
 
 ## Dependencies
 
-- [chroma-js](https://github.com/gka/chroma.js): JavaScript library for color conversions
-- [get-pixels](https://github.com/scijs/get-pixels): Reads the pixels of an image as an ndarray
-- [get-rgba-palette](https://github.com/mattdesl/get-rgba-palette): gets a palette of prominent colors from an array of pixels
-- [get-svg-colors](https://github.com/colorjs/get-svg-colors): Extract stroke and fill colors from SVG files
+- [chroma-js][chroma.js]: JavaScript library for color conversions
+- [get-pixels][]: Reads the pixels of an image as an ndarray
+- [get-rgba-palette][]: Gets a palette of prominent colors from an array of pixels
+- [get-svg-colors](https://npmjs.com/package/get-svg-colors): Extract stroke and fill colors from SVG files
 
 ## Dev Dependencies
 
-- [mocha](https://github.com/mochajs/mocha): simple, flexible, fun test framework
+- [eslint](https://npmjs.com/package/eslint): ECMAScript/JavaScript linter
+- [mocha](https://npmjs.com/package/mocha): Simple, flexible, fun test framework
+- [prettier](https://npmjs.com/package/prettier): Opinionated code formatter
 
 ## License
 
 MIT
+
+[chroma.js]: https://npmjs.com/package/chroma-js
+[get-pixels]: https://npmjs.com/package/get-pixels
+[get-rgba-palette]: https://npmjs.com/package/get-rgba-palette