(fix): responsive variants for base when slots are present

[w0ofy]

Description

cc @codecaaron

While trying to use responsiveVariants with slots present, any responsive props passed were not output in the component's classname.

---

What is the purpose of this pull request?

Ensure that responsive classnames are applied to base correctly when slots are also used.

• Bug fix

Here's a minimal code example of the issue:

// example
const button = tv(
    {
        base: 'inline-flex cursor-pointer gap-2 ...',
        slots: {
            icon: 'w-4 h-4 aspect-square pointer-events-auto',
        },
        variants: {
            size: {
                xs: 'text-xs',
                sm: 'text-sm',
                md: 'text-md',
            },
        },
    },
    { responsiveVariants: true },
);

const Button = ({ children, icon: Icon, ...rest }) => {
        const { base, icon } = button(rest)
        return (
            <button {...rest} className={base()} ref={ref}>
                {children}
                {Icon && <Icon className={icon()} />}
            </button>
        );
    };

// responsive variants won't work as expected here. the output classname of this variant will result in undefined
<Button size={{ initial: 'xs', sm: 'sm' }} />

[w0ofy]

This ensures line 266 is evaluated and returns the variantValue as a string

[codecaaron]

Note for context the issue is related to the logic here:
https://github.com/nextui-org/tailwind-variants/pull/202/files#diff-bfe9874d239014961b1ae4e89875a6155667db834a410aaaa2ebe3cf89820556L260-R269

      for (const variant in variants) {
        const variantValue = getVariantValue(variant, variants, slotKey, slotProps);
        const value =
          slotKey === "base" && typeof variantValue === "string"
            ? variantValue
            : variantValue && variantValue[slotKey];
        if (value) {
          result[result.length] = value;
        }
      }

The return value of getVaraintValue when slotKey === "base" can also be an array of responsive classnames - which fails the boolean in the above logic, the right hand side of the ternary then attempts to get the value of the key base on the array, returning undefined erroneously. It's unclear if the object case of this ternary is required for functionality in different configurations - the current suggested change simply ensures that the return type of getVariantValue doesn't fail this check and remains agnostic to other behaviors that may rely on the ternary logic here.

[jrgarciadev]

@tianenpang please check this

[tianenpang]

Hi @jrgarciadev LGTM 🚀 also test case added 🧪 and thanks to @w0ofy for the fix 🙏