Type Definition file presents incorrect type for the custom validation function

[Eosis]

While working on a form with a custom validation function, I encountered behaviour inconsistent with the type declaration file:
The validate function is typed as taking the entire form props as an argument, when in reality it only receives the latest updated value. See below:

svelte-forms-lib/lib/index.d.ts

Lines 6 to 12 in 7df1b1d

	export type FormProps<Inf = Record<string, unknown>> = {
	context?: FormState;
	initialValues?: Inf;
	onSubmit?: ((values: Inf) => any) | ((values: Inf) => Promise<any>);
	validate?: (values: Inf) => any | undefined;
	validationSchema?: ObjectSchema<any>;
	} & svelte.JSX.HTMLAttributes<HTMLFormElement>;

svelte-forms-lib/lib/create-form.js

Lines 90 to 100 in 7df1b1d

	if (validateFunction) {
	isValidating.set(true);
	return Promise.resolve()
	.then(() => validateFunction({[field]: value}))
	.then((errs) =>
	util.update(errors, field, !util.isNullish(errs) ? errs[field] : ''),
	)
	.finally(() => {
	isValidating.set(false);
	});
	}

A quick fix would be to set the type of the argument to validate to be Partial<Inf>.

Longer term, it would probably be preferable to return the full type (all the values in the form) to the custom validate function, as this would allow behaviour such as ensuring validity of a form where two of the fields are linked, which currently is not possible.