Fix: prevent null/undefined in Snowboard.request createFormData

[phpiando]

Problem

When using Snowboard.request() with data that includes null or undefined values, a TypeError is thrown due to Object.entries() not accepting such values.

Fix

A simple check for null or undefined was added at the beginning of the createFormData() function to prevent the error and silently skip those fields.

Reproduction Example

Snowboard.request('onSomething', {
    data: {
        name: 'phpiando',
        optionalField: null // This causes an error in current version
    }
});

This PR prevents that error.

[LukeTowers]

@phpiando so with this code change your example code would actually just send a request with name defined in the form data and not provide anything for optionalField at all? I feel like that's not necessarily what I would expect to happen. @bennothommo any thoughts on this one?

[phpiando]

@phpiando so with this code change your example code would actually just send a request with name defined in the form data and not provide anything for optionalField at all? I feel like that's not necessarily what I would expect to happen. @bennothommo any thoughts on this one?

Yep! this change would result in fields with null or undefined values being skipped entirely in the FormData.
In our use case, that behavior is preferred to avoid errors like:

TypeError: Cannot convert undefined or null to object

But!
Maybe a better solution would be to treat null and undefined as empty strings when appending to FormData, like:

if (data === null || data === undefined) {
    formData.append(prefix, '');
    return;
}

That way, the key is still sent, but it doesn't cause errors.

[LukeTowers]

That could work, but I'll wait for @bennothommo's thoughts on this