Added color utilities

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@ztimson/utils",
-	"version": "0.28.12",
+	"version": "0.28.14",
 	"description": "Utility library",
 	"author": "Zak Timson",
 	"license": "MIT",

src/color.ts

@@ -1,12 +1,73 @@
+import {dec2Hex} from './math.ts';
+
 /**
  * Determine if either black or white provides more contrast to the provided color
- * @param {string} background Color to compare against
+ * @param {string} color Color to compare against
  * @return {"white" | "black"} Color with the most contrast
  */
-export function contrast(background: string): 'white' | 'black' {
+export function contrast(color: string): 'white' | 'black' {
-	const exploded = background?.match(background.length >= 6 ? /[0-9a-fA-F]{2}/g : /[0-9a-fA-F]/g);
+	const exploded = color?.match(color.length >= 6 ? /[0-9a-fA-F]{2}/g : /[0-9a-fA-F]/g);
 	if(!exploded || exploded?.length < 3) return 'black';
 	const [r, g, b] = exploded.map(hex => parseInt(hex.length == 1 ? `${hex}${hex}` : hex, 16));
 	const luminance = (0.299 * r + 0.587 * g + 0.114 * b) / 255;
 	return luminance > 0.5 ? 'black' : 'white';
 }
+
+export function hex2Int(hex: string): {r: number, g: number, b: number} {
+	let r = 0, g = 0, b = 0;
+	if (hex.length === 4) {
+		r = parseInt(hex[1] + hex[1], 16);
+		g = parseInt(hex[2] + hex[2], 16);
+		b = parseInt(hex[3] + hex[3], 16);
+	} else {
+		r = parseInt(hex.slice(1, 3), 16);
+		g = parseInt(hex.slice(3, 5), 16);
+		b = parseInt(hex.slice(5, 7), 16);
+	}
+	return {r, g, b};
+}
+
+export function hue2rgb(p: number, q: number, t: number): number {
+	if(t < 0) t += 1;
+	if(t > 1) t -= 1;
+	if(t < 1 / 6) return p + (q - p) * 6 * t;
+	if(t < 1 / 2) return q;
+	if(t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
+	return p;
+}
+
+export function int2Hex(r: number, g: number, b: number) {
+	return '#' + dec2Hex(r) + dec2Hex(g) + dec2Hex(b);
+}
+
+/**
+ * Adjusts the darkness of a hex color.
+ * @param {string} hex - The hex color (e.g., '#ff0000').
+ * @param {number} amount - A value between -1 (black) and 1 (white)
+ */
+export function shadeColor(hex: string, amount: number) {
+	let {r, g, b} = hex2Int(hex);
+	r /= 255; g /= 255; b /= 255;
+	const max = Math.max(r, g, b), min = Math.min(r, g, b);
+	let h, s, l = (max + min) / 2;
+
+	if (max === min) {
+		h = s = 0;
+	} else {
+		const d = max - min;
+		s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
+		switch (max) {
+			case r: h = (g - b) / d + (g < b ? 6 : 0); break;
+			case g: h = (b - r) / d + 2; break;
+			case b: h = (r - g) / d + 4; break;
+			default: h = 0; break;
+		}
+		h /= 6;
+	}
+
+	// Adjust Lightness
+	l = Math.max(0, Math.min(1, l + amount));
+	const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+	const p = 2 * l - q;
+	return int2Hex(hue2rgb(p, q, h + 1/3), hue2rgb(p, q, h), hue2rgb(p, q, h - 1/3));
+};

src/math.ts

@@ -30,6 +30,10 @@ export function dec2Frac(num: number, maxDen=1000): string {
 		(numerator ? numerator + '/' + closest.d : '');
 }
 
+export function dec2Hex(num: number): string {
+	const hex = Math.round(num * 255).toString(16);
+	return hex.length === 1 ? '0' + hex : hex;
+}
 
 /**
  * Convert fraction to decimal number
@@ -42,7 +46,7 @@ export function dec2Frac(num: number, maxDen=1000): string {
  * @param {string} frac Fraction to convert
  * @return {number} Faction as a decimal
  */
-export function fracToDec(frac: string) {
+export function frac2Dec(frac: string) {
 	let split = frac.split(' ');
 	const whole = split.length == 2 ? Number(split[0]) : 0;
 	split = (<string>split.pop()).split('/');

src/template.ts

@@ -8,7 +8,16 @@ export class TemplateError extends BadRequestError { }
 export function findTemplateVars(html: string): Record<string, any> {
 	const variables = new Set<string>();
 	const arrays = new Set<string>();
-	const excluded = new Set<string>(['true', 'false', 'null', 'undefined']);
+	const excluded = new Set([
+		'let', 'const', 'var', 'function', 'if', 'while', 'do', 'this', 'typeof',
+		'new', 'instanceof', 'in', 'for', 'else', 'case', 'break', 'continue',
+		'switch', 'default', 'with', 'eval', 'arguments', 'void', 'delete', 'null',
+		'undefined', 'true', 'false', 'async', 'await', 'try', 'catch', 'finally',
+		'throw', 'return', 'yield', 'debugger', 'extends', 'import', 'export',
+		'class', 'super', 'static', 'get', 'set', 'constructor', 'enum', 'implements',
+		'interface', 'package', 'private', 'protected', 'public', 'abstract', 'final',
+		'native', 'synchronized', 'throws', 'transient', 'volatile'
+	]);
 
 	// Extract & exclude loop variables, mark arrays
 	for (const loop of matchAll(html, /\{\{\s*?\*\s*?(.+?)\s+in\s+(.+?)\s*?}}/g)) {
@@ -70,6 +79,7 @@ export function findTemplateVars(html: string): Record<string, any> {
 	}
 	return result;
 }
+
 export async function renderTemplate(template: string, data: any, fetch?: (file: string) => Promise<string>) {
 	if(!fetch) fetch = (file) => { throw new TemplateError(`Unable to fetch template: ${file}`); }
 

tests/math.spec.ts

@@ -1,4 +1,4 @@
-import { dec2Frac, fracToDec } from '../src';
+import { dec2Frac, frac2Dec } from '../src';
 
 describe('Math Utilities', () => {
 	describe('dec2Frac', () => {
@@ -27,25 +27,25 @@ describe('Math Utilities', () => {
 
 	describe('fracToDec', () => {
 		it('should convert mixed fraction to decimal', () => {
-			expect(fracToDec('1 1/4')).toBeCloseTo(1.25);
+			expect(frac2Dec('1 1/4')).toBeCloseTo(1.25);
-			expect(fracToDec('2 1/2')).toBeCloseTo(2.5);
+			expect(frac2Dec('2 1/2')).toBeCloseTo(2.5);
-			expect(fracToDec('3 3/4')).toBeCloseTo(3.75);
+			expect(frac2Dec('3 3/4')).toBeCloseTo(3.75);
 		});
 
 		it('should convert fraction without whole part to decimal', () => {
-			expect(fracToDec('3/4')).toBeCloseTo(0.75);
+			expect(frac2Dec('3/4')).toBeCloseTo(0.75);
-			expect(fracToDec('1/2')).toBeCloseTo(0.5);
+			expect(frac2Dec('1/2')).toBeCloseTo(0.5);
-			expect(fracToDec('1/10')).toBeCloseTo(0.1);
+			expect(frac2Dec('1/10')).toBeCloseTo(0.1);
 		});
 
 		it('should convert whole number fraction', () => {
-			expect(fracToDec('4 0/1')).toBeCloseTo(4);
+			expect(frac2Dec('4 0/1')).toBeCloseTo(4);
-			expect(fracToDec('0/1')).toBeCloseTo(0);
+			expect(frac2Dec('0/1')).toBeCloseTo(0);
 		});
 
 		it('should handle zero correctly', () => {
-			expect(fracToDec('0/1')).toBeCloseTo(0);
+			expect(frac2Dec('0/1')).toBeCloseTo(0);
-			expect(fracToDec('0 0/1')).toBeCloseTo(0);
+			expect(frac2Dec('0 0/1')).toBeCloseTo(0);
 		});
 	});
 });