Stack overflow when using toType on self-referential/recursive schema

[PowerSupply]

Reproduction:

const recursiveSchema = z.object({
    id: z.string(),
    get children() {
        return z.array(recursiveSchema);
    },
});

console.log(zx.toType(recursiveSchema));    // RangeError: Maximum call stack size exceeded

Probably related to #540 as well.

One possible solution to this could be to require a recursive schema to have a description (exist in the z.globalRegistry) so that you can use the description string as a value to break the infinite loop.

The proposes solution would also be nice to have for schemas that are not recursive, but contain other schemas, so that you could list them separately (using their description as placeholder where they are used in other schemas) instead of inlining all types.

I could try to make a PR if you agree with the proposed solution.

[PowerSupply]

Here is a quick solution i hacked together for listing subtypes separately (just to communicate the idea):

function getTypescriptType(typeName: string, zodType: ZodType) {
    let typeString = zx.toType(zodType, { typeName });

    getNamedSubtypes(zodType).forEach((subtype, description) => {
        let subtypeString = zx.toType(subtype);
        if (zx.tagged('enum')(subtype)) {
            subtypeString = `(${subtypeString})`; // Because zx.toType adds parenthesis around enums
        }
        typeString = typeString.replaceAll(subtypeString, description);

        typeString = typeString + `\n\n${zx.toType(subtype, { typeName: description })}`;
    });

    return simplePrettifyType(typeString);

    // Helper function
    function getNamedSubtypes(type: ZodType): Map<string, ZodType> {
        const subtypes = new Map<string, ZodType>();

        zx.fold<ZodType>((x) => {
            const traversedType = x as ZodType;
            if (z.globalRegistry.has(traversedType) && traversedType.description) {
                subtypes.set(traversedType.description, traversedType);
            }
            return traversedType;
        })(type);

        if (type.description) {
            // Name of main type is not a subtype
            subtypes.delete(type.description);
        }

        return subtypes;
    }
}