[Question] How do you unit test Jotai atoms?

Considering using Jotai for our production application.

It seems to fit all of our needs perfectly, but I haven’t been able to find any docs on testing Jotai atoms.

E.g. I created a simple themeAtom and setThemeAtom like this:

import { atom } from 'jotai'
import themes, { themeNameType } from 'src/lib/themes'

const DEFAULT_THEME = themes.light

export const themeAtom = atom(DEFAULT_THEME)
export const setThemeAtom = atom(
    (get) => get(themeAtom),
    (_, set, arg: themeNameType) => {
        set(themeAtom, themes[arg])
    })

How would I go about writing a unit test that makes sure when setTheme is called with a valid theme name, that the themeAtom updates to the expected theme?

Since Jotai only functions inside “React” do I have to write a dummy component with a dummy button to test my state management atoms?

Also interested in how I would test components that use useAtom. I’m guessing in this case I mock the useAtom, but it would be very helpful to have a guide/docs on the recommended way to do this.

Thanks!

[Noitidart]

Yes totally I’ll write a test for the above and share here and add it into docs if everyone likes it.

[dai-shi]

It seems to fit all of our needs perfectly, but I haven’t been able to find any docs on testing Jotai atoms.

It would be really nice to have docs/testing.md for sure.

Since Jotai only functions inside “React” do I have to write a dummy component with a dummy button to test my state management atoms?

Guess so. Do some files in tests help?

If you were just testing the functions for atom like read / write, you could test it without React, because they are just pure functions. But, to test a component/hook behavior, we’d need React.

Also interested in how I would test components that use useAtom.

Not sure what you mean by this. If you are testing a component behavior, you don’t need to mock useAtom. 🤔

it would be very helpful to have a guide/docs on the recommended way to do this.

Yeah. I’m not super experienced on testing best practices. Hope someone to volunteer. Otherwise, I’d try my best…