Use empty context for conditionals

[runfaj]

Provide a general summary of the issue here

This is kind of a bug and kind of a feature request, since behavior seems to vary across components. An example problem I'd like to solve is when inside a form, I'd like to automatically add some behavior and styling for any components contained within that form. For example, maybe a textfield on its own doesn't have a margin bottom, but if in a form, it would so there is consistent spacing between fields.

I would expect context to play the role in this and just be able to detect if context is present or has a value. However, at present, a form always provides an empty object (which matches the default context initialized) unless there's an error state, so there's no way to detect if in the form context or not.
context defined:

react-spectrum/packages/@react-stately/form/src/useFormValidationState.ts

Line 42 in 5e48753

export const FormValidationContext = createContext<ValidationErrors>({});

form provider:

react-spectrum/packages/react-aria-components/src/Form.tsx

Line 24 in 5e48753

<FormValidationContext.Provider value={validationErrors ?? {}}>

An obvious solution I can implement is my own form context, but that now means requiring my own form component wrapping the react-aria form, which seems like unnecessary overhead. I haven't tested other components, but similar situations might also appear in other contexts (like a custom label inside a textfield would need auto-spacing between the label and textfield).

🤔 Expected Behavior?

A context should always provide some value, never an empty object, so a child can detect if in another context or not.

😯 Current Behavior

See general summary

💁 Possible Solution

Ensure all react-aria components when defining a provider, also provide information in the context. Because there is context merging, maybe an object can't be avoided (null as default context would be ideal), but maybe the provider value could use something like { key: _.uniqueId() } so there's at least something to distinguish between the provider value and the default context value.

🔦 Context

No response

🖥️ Steps to Reproduce

See above

Version

1.0.0-rc.0

What browsers are you seeing the problem on?

Firefox, Chrome, Safari, Microsoft Edge

If other, please specify.

No response

What operating system are you using?

windows 11 and mac 14

🧢 Your Company/Team

No response

🕷 Tracking Issue

No response

[LFDanLu]

The team discussed this today and we can't change the default values of the context to be null now since it would be a breaking change. We suggest that you use your own context to provide this information or use some other method of communicating the existence of a wrapping Form (css var or something) for now.

[runfaj]

Thanks for looking into it. I would still recommend the key option long term, but I've gone with my own context for now.