Merge pull request markusn#22 from markusn/esm-module

convert to esm module, cjs support using rollup

Author: markusn

.gitignore

@@ -49,3 +49,6 @@ temp/
 coverage/
 .eslintcache
 .nyc_output
+
+# built using rollup
+index.cjs

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 1.4.0
+
+* Use ESM modules. Backwards compatible with CJS using rollup.
+* Replaced nyc with c8 (nyc does not support esm).
+
 ## 1.3.0
 
 * don't support mixing casing for r,g,b properties, either all upper or all lower

README.md

@@ -1,4 +1,5 @@
 # color-diff
+
 [![Build Status](https://github.com/markusn/color-diff/actions/workflows/build-latest.yaml/badge.svg?branch=master)](https://github.com/markusn/color-diff/actions/workflows/build-latest.yaml)
 [![Coverage Status](https://coveralls.io/repos/markusn/color-diff/badge.png?branch=master)](https://coveralls.io/r/markusn/color-diff?branch=master)
 
@@ -23,6 +24,7 @@ npm test
 ## Usage
 
 ```js
+// CommonJS
 const { 
   closest, 
   furthest,
@@ -32,7 +34,19 @@ const {
   rgbaToLab,
   mapPaletteLab,
   labPaletteMapKey,
-} = require('color-diff');
+} = require("color-diff");
+
+// ESM
+import {
+  closest,
+  furthest,
+  diff,
+  mapPalette,
+  paletteMapKey,
+  rgbaToLab,
+  mapPaletteLab,
+  labPaletteMapKey,
+} from "color-diff";
 ```
 
 ### closest(color, palette, bc)

index.js

@@ -1,5 +1,3 @@
-"use strict";
-
 // Types
 
 /**
@@ -21,18 +19,18 @@
  */
 
 // Imports
-const { rgbaToLab } = require("./lib/convert");
-const { ciede2000 } = require("./lib/diff");
-const {
+import { rgbaToLab } from "./lib/convert.js";
+import { ciede2000 } from "./lib/diff.js";
+import {
   mapPalette,
   paletteMapKey,
   matchPaletteLab,
   mapPaletteLab,
   labPaletteMapKey,
-} = require("./lib/palette");
+} from "./lib/palette.js";
 
 // Exports
-module.exports = {
+export {
   closest,
   closestLab,
   furthest,
@@ -42,7 +40,7 @@ module.exports = {
   matchPaletteLab,
   mapPaletteLab,
   labPaletteMapKey,
-  diff: ciede2000,
+  ciede2000 as diff,
   rgbaToLab,
   // eslint-disable-next-line camelcase
   rgb_to_lab,

lib/convert.js

@@ -1,5 +1,3 @@
-"use strict";
-
 /**
  * @author Markus Ekholm
  * @copyright 2012-2023 (c) Markus Ekholm <markus at botten dot org >
@@ -31,12 +29,7 @@
 /**
 * EXPORTS
 */
-module.exports = { rgbaToLab, normalize };
-
-/**
-* IMPORTS
-*/
-const pow = Math.pow;
+export { rgbaToLab, normalize };
 
 /**
  * TYPES
@@ -90,11 +83,11 @@ function rgbToXyz(c) {
   let G = (c.G / 255);
   let B = (c.B / 255);
 
-  if (R > 0.04045) R = pow(((R + 0.055) / 1.055), 2.4);
+  if (R > 0.04045) R = Math.pow(((R + 0.055) / 1.055), 2.4);
   else R = R / 12.92;
-  if (G > 0.04045) G = pow(((G + 0.055) / 1.055), 2.4);
+  if (G > 0.04045) G = Math.pow(((G + 0.055) / 1.055), 2.4);
   else G = G / 12.92;
-  if (B > 0.04045) B = pow(((B + 0.055) / 1.055), 2.4);
+  if (B > 0.04045) B = Math.pow(((B + 0.055) / 1.055), 2.4);
   else B = B / 12.92;
 
   R *= 100;
@@ -121,11 +114,11 @@ function xyzToLab(c) {
   let Y = c.Y / refY;
   let Z = c.Z / refZ;
   let X = c.X / refX;
-  if (X > 0.008856) X = pow(X, 1 / 3);
+  if (X > 0.008856) X = Math.pow(X, 1 / 3);
   else X = (7.787 * X) + (16 / 116);
-  if (Y > 0.008856) Y = pow(Y, 1 / 3);
+  if (Y > 0.008856) Y = Math.pow(Y, 1 / 3);
   else Y = (7.787 * Y) + (16 / 116);
-  if (Z > 0.008856) Z = pow(Z, 1 / 3);
+  if (Z > 0.008856) Z = Math.pow(Z, 1 / 3);
   else Z = (7.787 * Z) + (16 / 116);
   const L = (116 * Y) - 16;
   const a = 500 * (X - Y);

lib/diff.js

@@ -1,5 +1,3 @@
-"use strict";
-
 /**
  * @author Markus Ekholm
  * @copyright 2012-2023 (c) Markus Ekholm <markus at botten dot org >
@@ -29,24 +27,14 @@
  */
 
 /**
-* EXPORTS
+* IMPORTS
 */
-
-module.exports = { ciede2000 };
+import { rgbaToLab } from "./convert.js";
 
 /**
-* IMPORTS
+* EXPORTS
 */
-const sqrt = Math.sqrt;
-const pow = Math.pow;
-const cos = Math.cos;
-const atan2 = Math.atan2;
-const sin = Math.sin;
-const abs = Math.abs;
-const exp = Math.exp;
-const PI = Math.PI;
-
-const { rgbaToLab } = require("./convert");
+export { ciede2000 };
 
 /**
  * TYPES
@@ -101,19 +89,19 @@ function ciede2000(c1, c2, bc) {
   /**
    * Step 1: Calculate C1p, C2p, h1p, h2p
    */
-  const C1 = sqrt(pow(a1, 2) + pow(b1, 2)); // (2)
-  const C2 = sqrt(pow(a2, 2) + pow(b2, 2)); // (2)
+  const C1 = Math.sqrt(Math.pow(a1, 2) + Math.pow(b1, 2)); // (2)
+  const C2 = Math.sqrt(Math.pow(a2, 2) + Math.pow(b2, 2)); // (2)
 
   const aC1C2 = (C1 + C2) / 2.0; // (3)
 
-  const G = 0.5 * (1 - sqrt(pow(aC1C2, 7.0) /
-                          (pow(aC1C2, 7.0) + pow(25.0, 7.0)))); // (4)
+  const G = 0.5 * (1 - Math.sqrt(Math.pow(aC1C2, 7.0) /
+                          (Math.pow(aC1C2, 7.0) + Math.pow(25.0, 7.0)))); // (4)
 
   const a1p = (1.0 + G) * a1; // (5)
   const a2p = (1.0 + G) * a2; // (5)
 
-  const C1p = sqrt(pow(a1p, 2) + pow(b1, 2)); // (6)
-  const C2p = sqrt(pow(a2p, 2) + pow(b2, 2)); // (6)
+  const C1p = Math.sqrt(Math.pow(a1p, 2) + Math.pow(b1, 2)); // (6)
+  const C2p = Math.sqrt(Math.pow(a2p, 2) + Math.pow(b2, 2)); // (6)
 
   const h1p = hpF(b1, a1p); // (7)
   const h2p = hpF(b2, a2p); // (7)
@@ -125,7 +113,7 @@ function ciede2000(c1, c2, bc) {
   const dCp = C2p - C1p; // (9)
 
   const dhp = dhpF(C1, C2, h1p, h2p); // (10)
-  const dHp = 2 * sqrt(C1p * C2p) * sin(radians(dhp) / 2.0); // (11)
+  const dHp = 2 * Math.sqrt(C1p * C2p) * Math.sin(radians(dhp) / 2.0); // (11)
 
   /**
    * Step 3: Calculate CIEDE2000 Color-Difference
@@ -134,17 +122,17 @@ function ciede2000(c1, c2, bc) {
   const aCp = (C1p + C2p) / 2.0; // (13)
 
   const aHp = aHpF(C1, C2, h1p, h2p); // (14)
-  const T = 1 - 0.17 * cos(radians(aHp - 30)) + 0.24 * cos(radians(2 * aHp)) +
-    0.32 * cos(radians(3 * aHp + 6)) - 0.20 * cos(radians(4 * aHp - 63)); // (15)
-  const dRo = 30 * exp(-(pow((aHp - 275) / 25, 2))); // (16)
-  const RC = sqrt((pow(aCp, 7.0)) / (pow(aCp, 7.0) + pow(25.0, 7.0)));// (17)
-  const SL = 1 + ((0.015 * pow(aL - 50, 2)) /
-                sqrt(20 + pow(aL - 50, 2.0)));// (18)
+  const T = 1 - 0.17 * Math.cos(radians(aHp - 30)) + 0.24 * Math.cos(radians(2 * aHp)) +
+    0.32 * Math.cos(radians(3 * aHp + 6)) - 0.20 * Math.cos(radians(4 * aHp - 63)); // (15)
+  const dRo = 30 * Math.exp(-(Math.pow((aHp - 275) / 25, 2))); // (16)
+  const RC = Math.sqrt((Math.pow(aCp, 7.0)) / (Math.pow(aCp, 7.0) + Math.pow(25.0, 7.0)));// (17)
+  const SL = 1 + ((0.015 * Math.pow(aL - 50, 2)) /
+                Math.sqrt(20 + Math.pow(aL - 50, 2.0)));// (18)
   const SC = 1 + 0.045 * aCp;// (19)
   const SH = 1 + 0.015 * aCp * T;// (20)
-  const RT = -2 * RC * sin(radians(2 * dRo));// (21)
-  const dE = sqrt(pow(dLp / (SL * kL), 2) + pow(dCp / (SC * kC), 2) +
-                pow(dHp / (SH * kH), 2) + RT * (dCp / (SC * kC)) *
+  const RT = -2 * RC * Math.sin(radians(2 * dRo));// (21)
+  const dE = Math.sqrt(Math.pow(dLp / (SL * kL), 2) + Math.pow(dCp / (SC * kC), 2) +
+                Math.pow(dHp / (SH * kH), 2) + RT * (dCp / (SC * kC)) *
                 (dHp / (SH * kH))); // (22)
   return dE;
 }
@@ -159,7 +147,7 @@ function ciede2000(c1, c2, bc) {
  * @returns {number}
  */
 function degrees(n) {
-  return n * (180 / PI);
+  return n * (180 / Math.PI);
 }
 
 /**
@@ -168,7 +156,7 @@ function degrees(n) {
  * @returns number
  */
 function radians(n) {
-  return n * (PI / 180);
+  return n * (Math.PI / 180);
 }
 
 /**
@@ -180,7 +168,7 @@ function radians(n) {
 function hpF(x, y) { // (7)
   if (x === 0 && y === 0) return 0;
   else {
-    const tmphp = degrees(atan2(x, y));
+    const tmphp = degrees(Math.atan2(x, y));
     if (tmphp >= 0) return tmphp;
     else return tmphp + 360;
   }
@@ -196,7 +184,7 @@ function hpF(x, y) { // (7)
  */
 function dhpF(C1, C2, h1p, h2p) { // (10)
   if (C1 * C2 === 0) return 0;
-  else if (abs(h2p - h1p) <= 180) return h2p - h1p;
+  else if (Math.abs(h2p - h1p) <= 180) return h2p - h1p;
   else if ((h2p - h1p) > 180) return (h2p - h1p) - 360;
   else if ((h2p - h1p) < -180) return (h2p - h1p) + 360;
   else throw (new Error());
@@ -212,8 +200,8 @@ function dhpF(C1, C2, h1p, h2p) { // (10)
  */
 function aHpF(C1, C2, h1p, h2p) { // (14)
   if (C1 * C2 === 0) return h1p + h2p;
-  else if (abs(h1p - h2p) <= 180) return (h1p + h2p) / 2.0;
-  else if ((abs(h1p - h2p) > 180) && ((h1p + h2p) < 360)) return (h1p + h2p + 360) / 2.0;
-  else if ((abs(h1p - h2p) > 180) && ((h1p + h2p) >= 360)) return (h1p + h2p - 360) / 2.0;
+  else if (Math.abs(h1p - h2p) <= 180) return (h1p + h2p) / 2.0;
+  else if ((Math.abs(h1p - h2p) > 180) && ((h1p + h2p) < 360)) return (h1p + h2p + 360) / 2.0;
+  else if ((Math.abs(h1p - h2p) > 180) && ((h1p + h2p) >= 360)) return (h1p + h2p - 360) / 2.0;
   else throw (new Error());
 }

lib/palette.js

@@ -1,5 +1,3 @@
-"use strict";
-
 /**
  * @author Markus Ekholm
  * @copyright 2012-2023 (c) Markus Ekholm <markus at botten dot org >
@@ -28,23 +26,23 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/**
+* IMPORTS
+*/
+import { ciede2000 } from "./diff.js";
+import { normalize } from "./convert.js";
+
 /**
 * EXPORTS
 */
-module.exports = {
+export {
   mapPalette,
   mapPaletteLab,
   matchPaletteLab,
   paletteMapKey,
   labPaletteMapKey,
 };
 
-/**
-* IMPORTS
-*/
-const { ciede2000 } = require("./diff");
-const { normalize } = require("./convert");
-
 /**
  * TYPES
  */