chore: optimize terser options and code for minify

Author: webdiscus

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ansis",
-  "version": "4.0.0-rc.2",
+  "version": "4.0.0-rc.3",
   "description": "A small and fast library for applying ANSI colors in terminal or browser console",
   "keywords": [
     "ansi",

package.npm.json

@@ -1,6 +1,6 @@
 {
 "name":"ansis",
-"version":"4.0.0-rc.2",
+"version":"4.0.0-rc.3",
 "description":"ANSI color lib",
 "keywords":["ansi","color","cli"],
 "license":"ISC",

rollup.config.js

@@ -10,19 +10,23 @@ import { minify } from 'terser';
 
 // last ECMA version compatible with node.js 12
 //const ecma = 2019;
-const ecma = 2021;
+const ecma = 2020;
 
 const terserOptions = {
   ecma,
   // https://github.com/terser/terser#compress-options
   compress: {
     ecma,
-    passes: 2,
+    passes: 3,
     inline: true,
     //module: true, // omit 'use strict'
+    pure_getters: true,
+    // use these options to find potential for optimisations in code
+    //unsafe: true,
+    //unsafe_comps: true,
   },
   toplevel: true,
-}
+};
 
 // use this options only for debugging
 const debugTerserOptions = {

src/index.js

@@ -11,6 +11,7 @@ let bgOffset = 10;
 
 let styles = {};
 let stylePrototype;
+// @preserve
 let LF = '\n';
 
 /**
@@ -186,8 +187,8 @@ const Ansis = function(level = detectedLevel) {
   let fnRgb = createRgbFn(3, closeCode);
   let fnBgRgb = createRgbFn(4, bgCloseCode);
 
-  let fnAnsi256 = (code) => esc(`38;5;${code}`, closeCode);
-  let fnBgAnsi256 = (code) => esc(`48;5;${code}`, bgCloseCode);
+  let fnAnsi256 = (code) => esc(`38;5;` + code, closeCode);
+  let fnBgAnsi256 = (code) => esc(`48;5;` + code, bgCloseCode);
 
   if (level === LEVEL_256COLORS) {
     fnRgb = createRgb256Fn(fnAnsi256);
@@ -228,7 +229,7 @@ const Ansis = function(level = detectedLevel) {
     bgName = 'bg' + name[0].toUpperCase() + name.slice(1);
 
     // exclude bright colors for gray aliases as it is already "bright black"
-    if (offset < 8) {
+    if (8 > offset) {
       styleData[name + bright] = esc(90 + offset, closeCode);
       styleData[bgName + bright] = esc(100 + offset, bgCloseCode);
     } else {

src/utils.js

@@ -18,7 +18,7 @@ export let hexToRgb = (value) => {
   let color = /([a-f\d]{3,6})/i.exec(value)?.[1] ?? '';
   let len = color.length;
 
-  let hex = len === 3
+  let hex = 3 === len
     ? color[0] + color[0] + color[1] + color[1] + color[2] + color[2]
     // faster than 6 !== len
     : 6 ^ len ? '0': color;
@@ -40,7 +40,7 @@ export let hexToRgb = (value) => {
 export let rgbToAnsi256 = (r, g, b) => {
   // grayscale
   if (r === g && g === b) {
-    if (r < 8) return 16;
+    if (8 > r) return 16;
     if (r > 248) return 231;
     return round(((r - 8) * 24) / 247) + 232;
   }
@@ -61,20 +61,20 @@ export let rgbToAnsi256 = (r, g, b) => {
 export let ansi256To16 = (code) => {
   let r, g, b, value, remainder;
 
-  if (code < 8) return 30 + code;
-  if (code < 16) return 90 + (code - 8);
+  if (8 > code) return 30 + code;
+  if (16 > code) return 90 + (code - 8);
 
-  if (code >= 232) {
-    // grayscale
-    r = g = b = (((code - 232) * 10) + 8) / 255;
-  } else {
+  if (232 > code) {
     code -= 16;
     remainder = code % 36;
 
     // (number | 0) is equivalent to Math.floor(number), we are sure that the code is >= 0
     r = (code / 36 | 0) / 5;
     g = (remainder / 6 | 0) / 5;
     b = (remainder % 6) / 5;
+  } else {
+    // grayscale
+    r = g = b = (((code - 232) * 10) + 8) / 255;
   }
 
   value = max(r, g, b) * 2;