Fix: some random frontend fixes and coverage

src-ui/src/app/utils/color.spec.ts

@@ -1,8 +1,10 @@
 import {
   BRIGHTNESS,
+  componentToHex,
   computeLuminance,
   estimateBrightnessForColor,
   hexToHsl,
+  hslToRgb,
   randomColor,
   rgbToHsl,
 } from './color'
@@ -44,7 +46,21 @@ describe('Color Utils', () => {
     expect(hsl).toEqual([0, 0, 0.5019607843137255])
   })
 
+  it('should convert hsl to rgb', () => {
+    let rgb = hslToRgb(0, 0, 0.5)
+    expect(rgb).toEqual([127.5, 127.5, 127.5])
+    expect(hslToRgb(0, 0, 0)).toEqual([0, 0, 0])
+    expect(hslToRgb(0, 0, 1)).toEqual([255, 255, 255])
+  })
+
   it('should return a random color', () => {
     expect(randomColor()).not.toBeNull()
   })
+
+  it('should convert component to hex', () => {
+    expect(componentToHex(0)).toEqual('00')
+    expect(componentToHex(255)).toEqual('ff')
+    expect(componentToHex(128)).toEqual('80')
+    expect(componentToHex(15)).toEqual('0f')
+  })
 })

src-ui/src/app/utils/color.ts

@@ -5,7 +5,7 @@ export const BRIGHTNESS = {
   DARK: 'dark',
 }
 
-function componentToHex(c) {
+export function componentToHex(c) {
   var hex = Math.floor(c).toString(16)
   return hex.length == 1 ? '0' + hex : hex
 }
@@ -23,21 +23,22 @@ function componentToHex(c) {
  * @param   Number  l       The lightness
  * @return  Array           The RGB representation
  */
-function hslToRgb(h, s, l) {
+
+function hue2rgb(p, q, t) {
+  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 hslToRgb(h, s, l) {
   var r, g, b
 
   if (s == 0) {
     r = g = b = l // achromatic
   } else {
-    function hue2rgb(p, q, t) {
-      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
-    }
-
     var q = l < 0.5 ? l * (1 + s) : l + s - l * s
     var p = 2 * l - q
     r = hue2rgb(p, q, h + 1 / 3)