Gradient not working in a NodeJS env

[YoannMa]

Firstly, I would like to apologize, I'm pretty sure you are not supporting ChartJS on a non-browser environment, but I'm not sure if the bug is elsewhere than inside ChartJS. I will understand if you ask me to move my post to Stack Overflow instead.

Expected Behavior

Using ChartJS 3.6.0 in a NodeJS environment, I would like to pass a function to set a gradient as backgroundColor.

Current Behavior

The function is executed but the backgroundColor is not set and default to black. I can make it work with ChartJS 2.9.4 using a plugin

Possible Solution

I tried to apply the same idea as v2.9.4 using a plugin and modifying the backgroundColor attribute but without any success.

Steps to Reproduce

I made a relatively small repository showing my configuration in ChartJS v2 (2.9.4) and v3 (3.6.0) here :

https://github.com/YoannMa/chartjs-gradient-v3-node

I was able to reproduce my issue using canvas or skia-canvas under the hood. Using Puppeteer, give the expected result.

Context

Environment

• Chart.js version: 3.6.0 vs 2.9.4
• Browser name and version: Chrome stable (puppeteer) and Node 16.13.0
• Link to your project: https://github.com/YoannMa/chartjs-gradient-v3-node

[kurkle]

I'd suspect this:

Chart.js/src/helpers/helpers.color.js

Line 3 in 6c63f7a

const isPatternOrGradient = (value) => value instanceof CanvasGradient || value instanceof CanvasPattern;

Edit: I was wrong, its the config resolution that creates a proxy for those CanvasGradient implementations.

[YoannMa]

Thank you very much !