From f76a0f3fe07747039136505d4a17f7841910e3e6 Mon Sep 17 00:00:00 2001
From: Justin Meyer <justinbmeyer@gmail.com>
Date: Mon, 24 Sep 2018 09:34:35 -0500
Subject: [PATCH] #393 able to delete a key

---
 define-helpers/define-helpers.js |  2 +-
 map/map-test.js                  | 19 +++++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/define-helpers/define-helpers.js b/define-helpers/define-helpers.js
index 9d678a6..75fa21e 100644
--- a/define-helpers/define-helpers.js
+++ b/define-helpers/define-helpers.js
@@ -91,7 +91,7 @@ var defineHelpers = {
 			var oldValue = this._data[prop];
 			if(oldValue !== undefined) {
 				delete this._data[prop];
-				delete this[prop];
+				//delete this[prop];
 				this.dispatch({
 					type: prop,
 					target: this,
diff --git a/map/map-test.js b/map/map-test.js
index c0c39e9..017867d 100644
--- a/map/map-test.js
+++ b/map/map-test.js
@@ -9,6 +9,7 @@ var isPlainObject = canReflect.isPlainObject;
 var canTestHelpers = require("can-test-helpers/lib/dev");
 var DefineList = require("can-define/list/list");
 var dev = require("can-log/dev/dev");
+var ObservationRecorder = require("can-observation-recorder");
 
 var sealWorks = (function() {
 	try {
@@ -1395,10 +1396,9 @@ QUnit.test("deleteKey works (#351)", function(){
 
 	map.deleteKey("foo");
 
-	var pd = Object.getOwnPropertyDescriptor(map, "foo");
-
-
-	QUnit.ok(!pd, "no property descriptor");
+	// We should keep the property descriptor
+	// var pd = Object.getOwnPropertyDescriptor(map, "foo");
+	// QUnit.ok(!pd, "no property descriptor");
 
 	QUnit.deepEqual( canReflect.getOwnKeys(map), [] );
 
@@ -1412,6 +1412,17 @@ QUnit.test("deleteKey works (#351)", function(){
 	QUnit.equal(map.foo, undefined, "prop set to undefined");
 });
 
+QUnit.test("makes sure observation add is called (#393)", function(){
+	var map = new DefineMap({foo: "bar"});
+
+	canReflect.deleteKeyValue(map, "foo");
+
+	ObservationRecorder.start();
+	(function(){ return map.foo; }());
+	var result = ObservationRecorder.stop();
+	QUnit.deepEqual(canReflect.toArray( result.keyDependencies.get(map) ), ["foo"], "toArray" );
+});
+
 QUnit.test("type called with `this` as the map (#349)", function(){
 	var Type = DefineMap.extend({
 		foo: {