Any reason what this demonstrates is not a TestBox bug:

describe("Tests of testBox's toHaveKey", () => {
    it("is a control test", () => {
        st = {key="value"}
        expect(st).toHaveKey("key") // pass
    })
    it("handles a key with a null value", () => {
        st = {key=javacast("null", "")}
        expect(st).toHaveKey("key") // The key(s) [key] does not exist in the target object. Found keys are [[KEY]]
    })
    it("demonstrates the key does in fact exist", () => {
        st = {key=javacast("null", "")}
        expect(st.keyArray()).tobe(["key"]) // pass
    })
})

Same behaviour in CF and Lucee. (ping @lmajano)