Types appear to be wrong for scriptable options

[rhysviz]

Expected Behavior

I am using a function as the value of backgroundColor on a bar chart. The allowed types should include a function that returns a color.

Current Behavior

The allowed types do not include a funciton:

Type '(context: any, options: any) => string' is not assignable to type 'string | _DeepPartialObject<CanvasGradient> | _DeepPartialObject<CanvasPattern> | undefined'.

Steps to Reproduce

https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBAbzgYQBYENYBo5QKYDmwAzjHlOgEYA2exOamMyEAdgGbAECuFMwbBhlgARdDHRwAvnHZQIIOAHIAxsJgA6AFbElAbgBQRlW1JwCeZm04E4AXjgAKAJQAuFOpYcuvcQNYAPEqUmEoAfPYRCAZwsbiWvKyIMXGpMACeYHjuwaFYKamxEGD8pu7RhXEhKgDWBPLcrAAmLNTQ7iasZAAe8HZRBZVx+DCJygDE7FNKg6lS+UPSg1IGUkA

import { ChartConfiguration } from 'chart.js';

const getConfig = (): ChartConfiguration<'bar'> => {
    return {
        type: 'bar',
        options: {
        backgroundColor: context => {
            return '#fff'
        },
        }
    }
}

Environment

• Chart.js version: 3.5.0
• Typescript: 4.3.5

[LeeLenaleee]

It seems to be just fine, reason it fails in your example is that you return null as posted in #9665 this is a bug, if I indeed return a string it works fine:

https://www.typescriptlang.org/play?#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

[rhysviz]

In my example I return a string so I'm not sure its the same thing? I think the issue is that the type of the top level scriptable options is not correct.

[LeeLenaleee]

Seems something went wrong loading your link but it still works as intended since the backgroundColor is not configured in the options but at the dataset, see last link for working no erros

[rhysviz]

I am just using options.datasets.bar.backgroundColor instead so I guess this is a bug report rather than a request for help but thank you.

It seems to me that either the types are wrong or the implementation is wrong as it does work i.e. you can set the background color using a backgroundColor function in the options namespace.

I think the docs are a bit confusing if you are not meant to do that. I interpreted the page here (https://www.chartjs.org/docs/latest/charts/bar.html) as saying any of those options were available in any of the listed namespaces.

[LeeLenaleee]

Mb it indeed is configurable there, in that case it's indeed an issue with the typing