some tests for register user page

tests/unit/RegisterUserComponent.spec.js

+import { mount } from "@vue/test-utils";
+import RegisterFormComponent from "@/components/RegisterFormComponent";
+
+describe("RegisterFormComponent", () => {
+  let wrapper;
+
+  beforeEach(() => {
+    wrapper = mount(RegisterFormComponent);
+  });
+
+  it("renders correctly", () => {
+    expect(wrapper.element).toMatchSnapshot();
+  });
+
+  it("is instantiated", () => {
+    expect(wrapper.exists()).toBeTruthy();
+  });
+
+  it("renders error message to user", async () => {
+    await wrapper.setData({ errorMessage: "test message" });
+    expect(wrapper.find('li[data-test="customErrorMsg"]').text()).toBe(
+      "test message"
+    );
+  });
+
+  it("renders the h2 text correctly", () => {
+    expect(wrapper.find("h2").text()).toBe("Opprett ny bruker");
+  });
+
+  it("has a button", () => {
+    expect(wrapper.exists("button")).toBe(true);
+  });
+
+  it("updates data when field is updated", async () => {
+    await wrapper.find('input[data-test="firstNameTest"]').setValue("Gunnar");
+    expect(wrapper.vm.firstName).toBe("Gunnar");
+  });
+
+  it("displays 5 error messages when submit is clicked with no data", async () => {
+    await wrapper.find("button").trigger("click");
+    expect(wrapper.findAll("li").length).toBe(5);
+  });
+
+  /*   it("button click with correct sum", () => {
+    wrapper.setData({ guess: "15" });
+    const button = wrapper.find("button");
+    button.trigger("click");
+    expect(wrapper.vm.message).toBe("SUCCESS!");
+  }); */
+});