rgbToHsb() fails on input containing { red: 255 }

[emcmanus]

Issue summary

rgbToHsb() fails on any input containing { red: 255 }

I think the error is related to how rgbToHsb calculates hue when red is the largest color value.

Expected behavior

rgbToHsb({red: 255, green: 0, blue: 183, alpha: 1})

This should return { hue: 317, ... }, which you can calculate using http://www.workwithcolor.com/color-converter-01.htm

Actual behavior

rgbToHsb({red: 255, green: 0, blue: 183, alpha: 1})

This incorrectly returns { hue: 0, ... }

Steps to reproduce the problem

1. import { rgbToHsb } from "@shopify/polaris";
2. Call rgbToHsb() with a value containing { red: 255 }

Specifications

• Polaris version: 1.9.1 (present since v1.0.1)
• React version: N/A
• Browser: N/A
• Device: N/A
• Operating System: N/A

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[emcmanus]

Here's the fix e2a72fe

[emcmanus]

Incidentally by rounding hue before the return you introduce precision loss that prevents a proper mapping between HSB and RGB.

[dfmcphee]

Hey @emcmanus, thanks for the issue. This should now be fixed as of 1.10.0.