[unit] 添加button测试用例

test/unit/specs/button.spec.js

@@ -0,0 +1,24 @@
+import { createVue, destroyVM } from '../util';
+
+describe('Button.vue', () => {
+  let vm;
+  afterEach(() => {
+    destroyVM(vm);
+  });
+
+  it('should render as <a>', done => {
+    vm = createVue(`
+      <Button to="http://www.thinkinfe.tech/">Think in FE</Button>
+    `);
+    expect(vm.$el.tagName).to.equal('A');
+    done();
+  });
+
+  it('should render as <button>', done => {
+    vm = createVue(`
+      <Button>Think in FE</Button>
+    `);
+    expect(vm.$el.tagName).to.equal('BUTTON');
+    done();
+  });
+});