[REF] utils: remove id generator

tests/utils.test.ts

@@ -1,7 +1,6 @@
 import {
   escape,
   htmlTrim,
-  idGenerator,
   memoize,
   debounce,
   findInTree,
@@ -35,15 +34,6 @@ describe("htmlTrim", () => {
   });
 });
 
-describe("idGenerator", () => {
-  test("basic use", () => {
-    let gen = idGenerator();
-    expect(gen()).toBe(1);
-    expect(gen()).toBe(2);
-    expect(gen()).toBe(3);
-  });
-});
-
 describe("memoize", () => {
   test("return correct value", () => {
     const f = memoize((a, b) => a + b);