refactor: Exploring idea of shared core lib

src/color-thief-node.js

@@ -1,9 +1,8 @@
 const getPixels = require('get-pixels');
 const quantize = require('quantize');
+const core = require('./core-node.js');
 
-const ColorThief = function () {};
-
-function readImg(img) {
+function loadImg(img) {
     return new Promise((resolve, reject) => {
         getPixels(img, function(err, data) {
             if(err) {
@@ -15,22 +14,6 @@ function readImg(img) {
     });
 }
 
-function createPixelArray(imgData, quality) {
-    const pixels = imgData.data;
-    const pixelCount = imgData.shape[0] * imgData.shape[1];
-    const pixelArray = [];
-
-    for (let i = 0, offset, r, g, b, a; i < pixelCount; i = i + quality) {
-        offset = i * 4;
-        r = pixels[offset + 0];
-        g = pixels[offset + 1];
-        b = pixels[offset + 2];
-        a = pixels[offset + 3];
-        pixelArray.push([r, g, b]);
-    }
-    return pixelArray;
-}
-
 function getColor(img, quality) {
     return new Promise((resolve, reject) => {
         getPalette(img, 5, quality)
@@ -46,11 +29,14 @@ function getColor(img, quality) {
 
 function getPalette(img, colorCount = 10, quality = 10) {
     return new Promise((resolve, reject) => {
-        readImg(img)
+        loadImg(img)
             .then(imgData => {
-                const pixelArray = createPixelArray(imgData, quality);
+                const pixelCount = imgData.shape[0] * imgData.shape[1];
+                const pixelArray = core.createPixelArray(imgData.data, pixelCount, quality);
+
                 const cmap = quantize(pixelArray, colorCount);
                 const palette = cmap? cmap.palette() : null;
+
                 resolve(palette);
             })
             .catch(err => {

src/color-thief.js

@@ -1,4 +1,5 @@
 import quantize from '../node_modules/quantize/dist/index.mjs';
+import core from './core.js';
 
 /*
  * Color Thief v2.2.0
@@ -60,7 +61,7 @@ var ColorThief = function () {};
  * most dominant color.
  *
  * */
-ColorThief.prototype.getColor = function(sourceImage, quality) {
+ColorThief.prototype.getColor = function(sourceImage, quality = 10) {
     var palette       = this.getPalette(sourceImage, 5, quality);
     var dominantColor = palette[0];
     return dominantColor;
@@ -99,21 +100,7 @@ ColorThief.prototype.getPalette = function(sourceImage, colorCount, quality) {
     var pixels     = imageData.data;
     var pixelCount = image.getPixelCount();
 
-    // Store the RGB values in an array format suitable for quantize function
-    var pixelArray = [];
-    for (var i = 0, offset, r, g, b, a; i < pixelCount; i = i + quality) {
-        offset = i * 4;
-        r = pixels[offset + 0];
-        g = pixels[offset + 1];
-        b = pixels[offset + 2];
-        a = pixels[offset + 3];
-        // If pixel is mostly opaque and not white
-        if (a >= 125) {
-            if (!(r > 250 && g > 250 && b > 250)) {
-                pixelArray.push([r, g, b]);
-            }
-        }
-    }
+    const pixelArray = core.createPixelArray(imageData, pixelCount, quality);
 
     // Send array to quantize function which clusters values
     // using median cut algorithm

src/core-node.js

@@ -0,0 +1,24 @@
+function createPixelArray(imgData, pixelCount, quality) {
+    const pixels = imgData;
+    const pixelArray = [];
+
+    for (let i = 0, offset, r, g, b, a; i < pixelCount; i = i + quality) {
+        offset = i * 4;
+        r = pixels[offset + 0];
+        g = pixels[offset + 1];
+        b = pixels[offset + 2];
+        a = pixels[offset + 3];
+
+        // If pixel is mostly opaque and not white
+        if (typeof a === 'undefined' || a >= 125) {
+            if (!(r > 250 && g > 250 && b > 250)) {
+                pixelArray.push([r, g, b]);
+            }
+        }
+    }
+    return pixelArray;
+}
+
+module.exports = {
+    createPixelArray
+};

src/core.js

@@ -0,0 +1,24 @@
+function createPixelArray(imgData, pixelCount, quality) {
+    const pixels = imgData;
+    const pixelArray = [];
+
+    for (let i = 0, offset, r, g, b, a; i < pixelCount; i = i + quality) {
+        offset = i * 4;
+        r = pixels[offset + 0];
+        g = pixels[offset + 1];
+        b = pixels[offset + 2];
+        a = pixels[offset + 3];
+
+        // If pixel is mostly opaque and not white
+        if (typeof a === 'undefined' || a >= 125) {
+            if (!(r > 250 && g > 250 && b > 250)) {
+                pixelArray.push([r, g, b]);
+            }
+        }
+    }
+    return pixelArray;
+}
+
+export default {
+    createPixelArray,
+}