From 541b61a149977464ba58b8af3353f69cba3113e3 Mon Sep 17 00:00:00 2001
From: Henning Pohlmeyer <hpohlmeyer@users.noreply.github.com>
Date: Fri, 30 Aug 2019 08:16:30 +0200
Subject: [PATCH] Expose isLight and isDark functions

---
 src/index.ts        |  6 ++++++
 tests/index.test.ts | 12 +++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 6a19c15..68e3fc0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,4 @@
+import tinycolor from 'tinycolor2';
 import generate from './generate';
 
 export interface PalettesProps {
@@ -43,8 +44,13 @@ const purple = presetPalettes.purple;
 const magenta = presetPalettes.magenta;
 const grey = presetPalettes.grey;
 
+const isLight = (color: string): boolean => tinycolor(color).isLight();
+const isDark = (color: string): boolean => tinycolor(color).isDark();
+
 export {
   generate,
+  isLight,
+  isDark,
   presetPalettes,
   presetPrimaryColors,
   red,
diff --git a/tests/index.test.ts b/tests/index.test.ts
index f36f5d5..5bd38d0 100644
--- a/tests/index.test.ts
+++ b/tests/index.test.ts
@@ -1,4 +1,4 @@
-import { generate, presetPalettes } from '../src';
+import { generate, isLight, isDark, yellow, purple, presetPalettes } from '../src';
 
 export const blueColors = [
   '#E6F7FF',
@@ -17,6 +17,16 @@ test('Generate palettes from a given color', () => {
   expect(generate('#1890ff')).toEqual(blueColors);
 });
 
+test('Determine the lightness of a color', () => {
+  expect(isLight(yellow[5])).toEqual(true);
+  expect(isLight(purple[5])).toEqual(false);
+});
+
+test('Determine the darkness of a color', () => {
+  expect(isDark(yellow[5])).toEqual(false);
+  expect(isDark(purple[5])).toEqual(true);
+});
+
 test('should contain preseted palettes', () => {
   expect(Object.keys(presetPalettes)).toEqual([
     'red',