From 9740a61f54503368215273ba8c525f32e17feb04 Mon Sep 17 00:00:00 2001
From: Travis Kaufman <traviskaufman@google.com>
Date: Wed, 8 Feb 2017 14:51:03 -0500
Subject: [PATCH] fix(base): Ensure this.root_ is available within
 getDefaultFoundation()

Fixes #242
---
 packages/mdc-base/component.js       | 6 ++++--
 test/unit/mdc-base/component.test.js | 8 ++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/packages/mdc-base/component.js b/packages/mdc-base/component.js
index f63c4d91771..54718d7d66e 100644
--- a/packages/mdc-base/component.js
+++ b/packages/mdc-base/component.js
@@ -25,10 +25,12 @@ export default class MDCComponent {
     return new MDCComponent(root, new MDCFoundation());
   }
 
-  constructor(root, foundation = this.getDefaultFoundation(), ...args) {
+  constructor(root, foundation = undefined, ...args) {
     this.root_ = root;
     this.initialize(...args);
-    this.foundation_ = foundation;
+    // Note that we initialize foundation here and not within the constructor's default param so that
+    // this.root_ is defined and can be used within the foundation class.
+    this.foundation_ = foundation === undefined ? this.getDefaultFoundation() : foundation;
     this.foundation_.init();
     this.initialSyncWithDOM();
   }
diff --git a/test/unit/mdc-base/component.test.js b/test/unit/mdc-base/component.test.js
index 79f86f01f5f..8f7ed9229a4 100644
--- a/test/unit/mdc-base/component.test.js
+++ b/test/unit/mdc-base/component.test.js
@@ -33,6 +33,7 @@ class FakeComponent extends MDCComponent {
     return td.object({
       isDefaultFoundation: true,
       init: () => {},
+      rootElementAtTimeOfCall: this.root_,
     });
   }
 
@@ -163,3 +164,10 @@ test('#emit dispatches a custom event with the supplied data', (t) => {
   t.deepEqual(evt.detail, data);
   t.end();
 });
+
+test('(regression) ensures that this.root_ is available for use within getDefaultFoundation()', (t) => {
+  const root = document.createElement('div');
+  const f = new FakeComponent(root);
+  t.equal(f.foundation.rootElementAtTimeOfCall, root);
+  t.end();
+});