skipNull and skipEmptyString are not working as intended

[closingin]

Hello there!

I've just installed query-string@^5.1.1 on my project, and both skipNull and skipEmptyString are not working as intended, they do not remove null/empty items from the returned string 🤔

I checked against a sample from your documentation:

queryString.stringify({ a: 1, b: '', c: null, d: 4 }, {
    skipNull: true,
    skipEmptyString: true
})
// a=1&b=&c&d=4

Maybe a regression?

[sindresorhus]

You're not using the latest version of this package.

[closingin]

Oh my. I'm so sorry, my npm installed this version by default, I don't know why. Thanks.