const { lowCaseKeys, upCaseKeys } = require("objectkeys-case");

const data = {
    Foo: "foo",
    BAR: "BAR",
    Baz: {
        SUb1: "sub1",
        sUb2: "sub2",
    }
};

const lower = lowCaseKeys(data);

/*
lower
{
    foo: "foo",
    bAR: "BAR",
    baz: {
        sUb1: "sub1",
        sUb2: "sub2"
    }
}
*/

const upper = upCaseKeys(data);

/*
upper
{
    Foo: "foo",
    BAR: "BAR",
    Baz: {
        SUb1: "sub1",
        SUb2: "sub2"
    }
}
*/