From c6675db07fd17518a9fe5c46266026745ba40b4a Mon Sep 17 00:00:00 2001
From: Steven Orvell <sorvell@google.com>
Date: Thu, 9 Jan 2020 15:18:54 -0800
Subject: [PATCH] `legacyNoObservedAttributes`: Ensure user created runs before
 attributesChanged

---
 lib/legacy/legacy-element-mixin.js | 19 +++++++++----------
 test/unit/legacy-noattributes.html |  8 ++++++++
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/lib/legacy/legacy-element-mixin.js b/lib/legacy/legacy-element-mixin.js
index a6c0575c3a..76c0682dcb 100644
--- a/lib/legacy/legacy-element-mixin.js
+++ b/lib/legacy/legacy-element-mixin.js
@@ -122,16 +122,7 @@ export const LegacyElementMixin = dedupingMixin((base) => {
      * @override
      * @return {void}
      */
-    created() {
-      // Pull all attribute values 1x if `legacyNoObservedAttributes` is set.
-      if (legacyNoObservedAttributes && this.hasAttributes()) {
-        const a = this.attributes;
-        for (let i=0, l=a.length; i < l; i++) {
-          const attr = a[i];
-          this.__attributeReaction(attr.name, null, attr.value);
-        }
-      }
-    }
+    created() {}
 
     /**
      * Processes an attribute reaction when the `legacyNoObservedAttributes`
@@ -310,6 +301,14 @@ export const LegacyElementMixin = dedupingMixin((base) => {
         super._initializeProperties();
         this.root = /** @type {HTMLElement} */(this);
         this.created();
+        // Pull all attribute values 1x if `legacyNoObservedAttributes` is set.
+        if (legacyNoObservedAttributes && this.hasAttributes()) {
+          const a = this.attributes;
+          for (let i=0, l=a.length; i < l; i++) {
+            const attr = a[i];
+            this.__attributeReaction(attr.name, null, attr.value);
+          }
+        }
         // Ensure listeners are applied immediately so that they are
         // added before declarative event listeners. This allows an element to
         // decorate itself via an event prior to any declarative listeners
diff --git a/test/unit/legacy-noattributes.html b/test/unit/legacy-noattributes.html
index 1e25a99570..91b45662f3 100644
--- a/test/unit/legacy-noattributes.html
+++ b/test/unit/legacy-noattributes.html
@@ -66,7 +66,11 @@
           camelCase: String,
           disabled: {type: Boolean, value: 'true'}
         },
+        created() {
+          this.wasCreated = true;
+        },
         attributeChanged(name, old, value) {
+          this.wasCreatedInAttributeChanged = this.wasCreated;
           this.attrInfo = {name, old, value};
         }
       });
@@ -104,6 +108,10 @@
         assert.equal(el.camelCase, 'camelCase');
       });
 
+      test('created called before attributeChanged', () => {
+        assert.isTrue(el.wasCreatedInAttributeChanged);
+      });
+
       test('attributeChanged gets expected arguments', () => {
         el = fixture('one-attr');
         assert.deepEqual(el.attrInfo, {name: 'foo', old: null, value: 'foo'});