docs: add alternative to hasAttribute

Author: eddyerburgh

docs/en/api/wrapper/hasAttribute.md

@@ -19,4 +19,19 @@ import Foo from './Foo.vue'
 
 const wrapper = mount(Foo)
 expect(wrapper.hasAttribute('id', 'foo')).to.equal(true)
-```
+```
+
+- **Alternative:**
+
+You could get the attribute from the `Wrapper.element` to have a value based assertion:
+
+```js
+import { mount } from 'vue-test-utils'
+import { expect } from 'chai'
+import Foo from './Foo.vue'
+
+const wrapper = mount(Foo)
+expect(wrapper.element.getAttribute('id')).to.equal('foo')
+```
+
+This makes for a more informative assertion error.