test: add controller tests

Co-authored-by: Kristján Oddsson <koddsson@gmail.com>

Author: keithamus

test/controller.js

@@ -0,0 +1,19 @@
+import {controller} from '../lib/controller.js'
+
+describe('controller', () => {
+  it('calls register', async () => {
+    class ControllerRegisterElement extends HTMLElement {}
+    controller(ControllerRegisterElement)
+    const instance = document.createElement('controller-register')
+    document.body.appendChild(instance)
+    expect(instance).to.be.instanceof(ControllerRegisterElement)
+  })
+
+  it('adds data-catalyst to elements', async () => {
+    controller(class ControllerDataAttrElement extends HTMLElement {})
+    const instance = document.createElement('controller-data-attr')
+    document.body.appendChild(instance)
+    expect(instance.hasAttribute('data-catalyst')).to.equal(true)
+    expect(instance.getAttribute('data-catalyst')).to.equal('')
+  })
+})