From 5d3f489c2b9898356da5337a2a60584007b58960 Mon Sep 17 00:00:00 2001
From: Andy Dvorak <advorak@google.com>
Date: Thu, 14 Feb 2019 10:59:08 -0800
Subject: [PATCH] WIP: Add unit test for missing static `attachTo()` method

---
 test/unit/mdc-auto-init/mdc-auto-init.test.js | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/test/unit/mdc-auto-init/mdc-auto-init.test.js b/test/unit/mdc-auto-init/mdc-auto-init.test.js
index c531ab266ba..9347f078a4b 100644
--- a/test/unit/mdc-auto-init/mdc-auto-init.test.js
+++ b/test/unit/mdc-auto-init/mdc-auto-init.test.js
@@ -36,6 +36,12 @@ class FakeComponent {
   }
 }
 
+class InvalidComponent {
+  constructor(node) {
+    this.node = node;
+  }
+}
+
 const createFixture = () => bel`
   <div id="root">
     <p data-mdc-auto-init="FakeComponent" class="mdc-fake">Fake Element</p>
@@ -48,6 +54,12 @@ const setupTest = () => {
   return createFixture();
 };
 
+const setupInvalidTest = () => {
+  mdcAutoInit.deregisterAll();
+  mdcAutoInit.register('InvalidComponent', InvalidComponent);
+  return createFixture();
+};
+
 suite('MDCAutoInit');
 
 test('calls attachTo() on components registered for identifier on nodes w/ data-mdc-auto-init attr', () => {
@@ -57,6 +69,11 @@ test('calls attachTo() on components registered for identifier on nodes w/ data-
   assert.isOk(root.querySelector('.mdc-fake').FakeComponent instanceof FakeComponent);
 });
 
+test('throws when attachTo() is missing', () => {
+  const root = setupInvalidTest();
+  assert.throws(() => mdcAutoInit(root));
+});
+
 test('passes the node where "data-mdc-auto-init" was found to attachTo()', () => {
   const root = setupTest();
   mdcAutoInit(root);