Additional tests

test/getType.test.js

@@ -7,3 +7,9 @@ test('getType is a Function', () => {
 test('Returns the native type of a value', () => {
   expect(getType(new Set([1, 2, 3]))).toBe('set');
 });
+test('Returns null for null', () => {
+  expect(getType(null)).toBe('null');
+});
+test('Returns undefined for undefined', () => {
+  expect(getType(undefined)).toBe('undefined');
+});