Rename lib as future home for other colour utils

Author: jamesmockett

dotcom-rendering/src/components/Distribution.tsx

@@ -1,6 +1,6 @@
 import { css } from '@emotion/react';
 import { headlineBold34, text } from '@guardian/source/foundations';
-import { isLight } from '../lib/isLight';
+import { isLight } from '../lib/colour';
 
 type Props = {
 	left: BarType;

dotcom-rendering/src/components/Doughnut.tsx

@@ -5,7 +5,7 @@ import {
 	text,
 	textSans15,
 } from '@guardian/source/foundations';
-import { isLight } from '../lib/isLight';
+import { isLight } from '../lib/colour';
 
 type Props = {
 	sections: SectionType[];

dotcom-rendering/src/components/GoalAttempts.tsx

@@ -4,7 +4,7 @@ import {
 	palette as sourcePalette,
 	textSans15,
 } from '@guardian/source/foundations';
-import { isLight } from '../lib/isLight';
+import { isLight } from '../lib/colour';
 import { transparentColour } from '../lib/transparentColour';
 import { palette as themePalette } from '../palette';
 import type { ColourName } from '../paletteDeclarations';

dotcom-rendering/src/lib/isLight.test.ts dotcom-rendering/src/lib/colour.test.tsdotcom-rendering/src/lib/isLight.test.ts renamed to dotcom-rendering/src/lib/colour.test.ts

@@ -1,4 +1,4 @@
-import { isLight } from './isLight';
+import { isLight } from './colour';
 
 describe('isLight', () => {
 	it('should return the correct response for dark hex colours', () => {

dotcom-rendering/src/lib/isLight.ts dotcom-rendering/src/lib/colour.tsdotcom-rendering/src/lib/isLight.ts renamed to dotcom-rendering/src/lib/colour.ts

@@ -1,9 +1,11 @@
 // https://stackoverflow.com/a/5624139
-function hexToRgb(hex: string): {
+const hexToRgb = (
+	hex: string,
+): {
 	r: number;
 	g: number;
 	b: number;
-} | null {
+} | null => {
 	// Expand shorthand form (e.g. "03F") to full form (e.g. "0033FF")
 	const shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
 	const fullHex = hex.replace(shorthandRegex, ([, r, g, b]) => {
@@ -19,13 +21,13 @@ function hexToRgb(hex: string): {
 				b: parseInt(b, 16),
 		  }
 		: null;
-}
+};
 
-function getBrightness(colour: string): number {
+const getBrightness = (colour: string): number => {
 	// http://www.w3.org/TR/AERT#color-contrast
 	const rgb = hexToRgb(colour);
 	return rgb ? (rgb.r * 299 + rgb.g * 587 + rgb.b * 114) / 1000 : 0;
-}
+};
 
 // Based on https://github.com/bgrins/TinyColor
 export const isLight = (colour: string): boolean => {