[FIX] re-introduce tests

tests/reactivity.test.ts

@@ -447,6 +447,50 @@ describe("observe", () => {
     obj2.key = 3;
     expect(n).toBe(1);
   });
+
+  test.skip("call callback when state is changed", async () => {
+    /*    const observer = new Observer();
+    observer.notifyCB = jest.fn();
+    const obj: any = observer.observe({ a: 1, b: { c: 2 }, d: [{ e: 3 }], f: 4 });
+
+    expect(observer.notifyCB).toBeCalledTimes(0);
+
+    obj.a = 2;
+    await nextMicroTick();
+    expect(observer.notifyCB).toBeCalledTimes(1);
+
+    obj.b.c = 3;
+    await nextMicroTick();
+    expect(observer.notifyCB).toBeCalledTimes(2);
+
+    obj.d[0].e = 5;
+    await nextMicroTick();
+    expect(observer.notifyCB).toBeCalledTimes(3);
+
+    obj.a = 111;
+    obj.f = 222;
+    await nextMicroTick();
+    expect(observer.notifyCB).toBeCalledTimes(5);*/
+  });
+
+  test.skip("throw error when state is mutated in object if allowMutation=false", async () => {
+    /*const observer = new Observer();
+    observer.allowMutations = false;
+    const obj: any = observer.observe({ a: 1 });
+    expect(() => {
+      obj.a = 2;
+    }).toThrow('Observed state cannot be changed here! (key: "a", val: "2")');*/
+  });
+
+  test.skip("throw error when state is mutated in array if allowMutation=false", async () => {
+    /*    const observer = new Observer();
+    observer.allowMutations = false;
+    const obj: any = observer.observe({ a: [1] });
+
+    expect(() => {
+      obj.a.push(2);
+    }).toThrow('Observed state cannot be changed here! (key: "1", val: "2")');*/
+  });
 });
 
 describe("unobserve", () => {