Add unit test for checkbox.vue.

To raise global percentage.

src/ux-components/checkbox/checkbox.spec.js

@@ -1 +1,85 @@
-test.todo("some test to be written in the future");
+import { shallowMount } from "@vue/test-utils";
+import checkbox from "./checkbox";
+import { nextTick } from "vue";
+
+describe("checkbox.vue", () => {
+
+  it("Should return checkbox name", async () => {
+    // Act
+    const wrapper = shallowMount(checkbox, {
+      propsData: {
+        checkboxName: "Checkbox"
+      },
+    });
+
+    // Assert
+    const input = wrapper.find("input");
+
+    // Expect
+    expect(input.attributes().name).toEqual("Checkbox");
+
+  });
+
+  it("Should return checkbox id", async () => {
+    // Act
+    const wrapper = shallowMount(checkbox, {
+      propsData: {
+        buttonID: "Checkbox ID"
+      },
+    });
+
+    // Assert
+    const input = wrapper.find("input");
+
+    // Expect
+    expect(input.attributes().id).toEqual("Checkbox ID");
+
+  });
+
+  it("Should return tabindex value", async () => {
+    // Act
+    const wrapper = shallowMount(checkbox, {
+      propsData: {
+        tabIndex: "1"
+      },
+    });
+
+    // Assert
+    const input = wrapper.find("input");
+
+    // Expect
+    expect(input.attributes().tabindex).toEqual("1");
+
+  });
+
+  it("Should return label text", async () => {
+    // Act
+    const wrapper = shallowMount(checkbox, {
+      propsData: {
+        checkboxLabel: "label text"
+      },
+    });
+
+    // Assert
+    const paragraph = wrapper.find("p");
+
+    expect(paragraph.text()).toEqual("label text");
+
+  });
+
+  it("Should return label text", async () => {
+    // Act
+    const wrapper = shallowMount(checkbox, {
+      propsData: {
+        screenReaderOnlyText: "screenreader text"
+      },
+    });
+
+    // Assert
+    const paragraph = wrapper.find("span");
+
+    expect(paragraph.text()).toEqual("screenreader text");
+
+  });
+
+});