Improve test cases from components and utils

src/utils/__tests__/decimalCount.spec.ts

@@ -0,0 +1,12 @@
+import { it, expect } from "vitest";
+import { decimalCount } from "../decimalCount";
+
+describe("decimalCount function test", () => {
+  it("decimalCount should return length 1 of decimal", () => {
+    expect(decimalCount("4.1")).toEqual(1);
+  });
+
+  it("decimalCount should return length 0 because no decimal found", () => {
+    expect(decimalCount("5")).toEqual(0);
+  });
+});