Add tests for Principal

shell/components/auth/__tests__/Principal.test.ts

@@ -0,0 +1,40 @@
+import { mount, type VueWrapper } from '@vue/test-utils';
+import Principal from '@shell/components/auth/Principal.vue';
+
+describe('component: Principal', () => {
+  it('should render the component', () => {
+    const wrapper = mount(Principal, {
+      props:  { value: 'whatever' },
+      global: { mocks: { $fetchState: { pending: false } } },
+    });
+
+    expect(wrapper.exists()).toBe(true);
+  });
+
+  it('should update principal displayed properties on value change', async() => {
+    const wrapper: VueWrapper<any, any> = mount(Principal, {
+      props:  { value: 'whatever' },
+      global: {
+        mocks: {
+          $fetchState: { pending: false },
+          $store:      {
+            getters: {
+              'rancher/byId': (_: any, id: 'first' | 'second') => {
+                const options = {
+                  first:  { name: 'first name' },
+                  second: { name: 'second name' }
+                };
+
+                return options[id];
+              }
+            }
+          },
+        },
+      },
+    });
+
+    await wrapper.setProps({ value: 'second' });
+
+    expect(wrapper.vm.principal.name).toStrictEqual('second name');
+  });
+});