$$\sum\limits\_{n=0}^{\infty} i^n z^n$$

I am new to complex analysis, but I assume we want to apply the ratio test to form:

$$\lim\_{n \to \infty} \left|\frac{i^{n+1} \ z^{n+1}}{i^n \ z^n}\right| = \lim\_{n \to \infty} |i z| < 1$$

Since $|i| = 1$, we are left with the disk of convergence being $|z| < 1$. Would I also need to formally calculate the series's convergence or divergence at $z = 1, -1$?

Thanks.