[WIP es-classes] Fix extending from ES Classes

packages/ember-metal/lib/meta.js

@@ -35,6 +35,7 @@ export const UNDEFINED = symbol('undefined');
 const SOURCE_DESTROYING = 1 << 1;
 const SOURCE_DESTROYED = 1 << 2;
 const META_DESTROYED = 1 << 3;
+const WAS_APPLIED = 1 << 5;
 
 const NODE_STACK = [];
 
@@ -157,6 +158,22 @@ export class Meta {
     return (this._flags & flag) === flag;
   }
 
+  get wasApplied() {
+    assert('cannot access wasApplied for an instances meta', this.proto === this.source);
+
+    return this._hasFlag(WAS_APPLIED);
+  }
+
+  set wasApplied(value) {
+    assert('cannot set wasApplied for an instances meta', this.proto === this.source);
+
+    if (value === true) {
+      this._flags |= WAS_APPLIED;
+    } else {
+      this._flags &= ~WAS_APPLIED;
+    }
+  }
+
   _getOrCreateOwnMap(key) {
     return this[key] || (this[key] = Object.create(null));
   }

packages/ember-runtime/lib/system/core_object.js

@@ -45,15 +45,15 @@ function makeCtor() {
   // method a lot faster. This is glue code so we want it to be as fast as
   // possible.
 
-  let wasApplied = false;
   let initFactory;
 
   class Class {
     constructor(properties) {
       let self = this;
+      let m = meta(this);
 
-      if (!wasApplied) {
-        Class.proto(); // prepare prototype...
+      if (!m.parent.wasApplied) {
+        this.constructor.proto(); // prepare prototype...
       }
 
       let beforeInitCalled; // only used in debug builds to enable the proxy trap
@@ -103,9 +103,12 @@ function makeCtor() {
             assert(messageFor(receiver, property), value === undefined);
           }
         });
+
+        // We've changed "self" so meta will necessarily change as well, due to it being a different
+        // object. Reset meta in this case as well.
+        m = meta(self);
       }
 
-      let m = meta(self);
       let proto = m.proto;
       m.proto = self;
 
@@ -208,22 +211,35 @@ function makeCtor() {
     }
 
     static willReopen() {
-      if (wasApplied) {
-        Class.PrototypeMixin = Mixin.create(Class.PrototypeMixin);
+      let m = meta(this.prototype);
+      if (m.wasApplied) {
+        this.PrototypeMixin = Mixin.create(this.PrototypeMixin);
       }
 
-      wasApplied = false;
+      m.wasApplied = false;
     }
 
     static _initFactory(factory) { initFactory = factory; }
 
     static proto() {
-      let superclass = Class.superclass;
-      if (superclass) { superclass.proto(); }
+      // Native classes set the prototype of the constructor to the superclass,
+      // so first we check to see if it exists and contains `proto`. If not, we
+      // look for a manually assigned superclass.
+      let superclass = Object.getPrototypeOf(this);
+
+      if (typeof superclass.proto === 'function') {
+        superclass.proto();
+      } else if (this.superclass) {
+        this.superclass.proto();
+      }
+
+      let m = meta(this.prototype);
 
-      if (!wasApplied) {
-        wasApplied = true;
-        Class.PrototypeMixin.applyPartial(Class.prototype);
+      // Setup proto incase it hasn't been setup, as in ES Class extend
+      m.proto = this.prototype;
+      if (!m.wasApplied) {
+        m.wasApplied = true;
+        this.PrototypeMixin.applyPartial(this.prototype);
       }
 
       return this.prototype;
@@ -682,10 +698,27 @@ let ClassMixinProps = {
     @public
   */
   extend() {
-    let Class = makeCtor();
-    let proto;
-    Class.ClassMixin = Mixin.create(this.ClassMixin);
-    Class.PrototypeMixin = Mixin.create(this.PrototypeMixin);
+    let Class, proto;
+
+    if (Object.getPrototypeOf(this) === Function.prototype) {
+      // The class we're extending is a base class, does not have anything
+      // else in the prototype chain, so continue as normal
+      Class = makeCtor();
+    } else {
+      // Create a simple wrapper class to defer to the rest of the prototype chain
+      // for native classes and classes that extend from native classes
+      Class = class extends this {};
+    }
+
+    if (this.hasOwnProperty('ClassMixin')) {
+      Class.ClassMixin = Mixin.create(this.ClassMixin);
+      Class.PrototypeMixin = Mixin.create(this.PrototypeMixin);
+    } else {
+      // Native classes do not have a ClassMixin or PrototypeMixin,
+      // create one using their constructor and prototype respectively
+      Class.ClassMixin = Mixin.create(this);
+      Class.PrototypeMixin = Mixin.create(this.prototype);
+    }
 
     Class.ClassMixin.ownerConstructor = Class;
     Class.PrototypeMixin.ownerConstructor = Class;
@@ -789,6 +822,7 @@ let ClassMixinProps = {
     @public
   */
   reopen() {
+    assert(`You cannot reopen ${this.name} because it was defined with native class syntax`, this.hasOwnProperty('PrototypeMixin'));
     this.willReopen();
     reopen.apply(this.PrototypeMixin, arguments);
     return this;
@@ -856,6 +890,7 @@ let ClassMixinProps = {
     @public
   */
   reopenClass() {
+    assert(`You cannot reopen ${this.name} because it was defined with native class syntax`, this.hasOwnProperty('ClassMixin'));
     reopen.apply(this.ClassMixin, arguments);
     applyMixin(this, arguments, false);
     return this;
@@ -1038,5 +1073,9 @@ ClassMixin.ownerConstructor = CoreObject;
 
 CoreObject.ClassMixin = ClassMixin;
 
+// ensure CoreObject itself has a proper class meta
+let proto = CoreObject.prototype;
+meta(proto).proto = proto;
+
 ClassMixin.apply(CoreObject);
 export default CoreObject;

packages/ember-runtime/tests/system/object/es-compatibility-test.js

@@ -36,37 +36,173 @@ QUnit.test('extending an Ember.Object', function(assert) {
   assert.equal(myObject.passedProperty, 'passed-property', 'passed property available on instance (new)');
 });
 
-QUnit.test('using super', function(assert) {
+QUnit.test('normal method super', function(assert) {
   let calls = [];
 
-  let SuperSuperObject = EmberObject.extend({
+  let Foo = EmberObject.extend({
     method() {
-      calls.push('super-super-method');
+      calls.push('foo');
     }
   });
 
-  let SuperObject = SuperSuperObject.extend({
+  let Bar = Foo.extend({
     method() {
       this._super();
-      calls.push('super-method');
+      calls.push('bar');
     }
   });
 
-  class MyObject extends SuperObject {
+  class Baz extends Bar {
     method() {
       super.method();
-      calls.push('method');
+      calls.push('baz');
     }
   }
 
-  let myObject = new MyObject();
-  myObject.method();
+  let Qux = Baz.extend({
+    method() {
+      this._super();
+      calls.push('qux');
+    }
+  });
+
+  let Quux = Qux.extend({
+    method() {
+      this._super();
+      calls.push('quux');
+    }
+  });
+
+
+  class Corge extends Quux {
+    method() {
+      super.method();
+      calls.push('corge');
+    }
+  }
+
+  let callValues = ['foo', 'bar', 'baz', 'qux', 'quux', 'corge'];
+
+  [Foo, Bar, Baz, Qux, Quux, Corge].forEach((Class, index) => {
+    calls = [];
+    new Class().method();
+
+    assert.deepEqual(calls, callValues.slice(0, index + 1), 'ch,ain of static methods called with super');
+  });
+});
+
+QUnit.test('static method super', function(assert) {
+  let calls;
+
+  let Foo = EmberObject.extend();
+  Foo.reopenClass({
+    method() {
+      calls.push('foo');
+    }
+  });
+
+  let Bar = Foo.extend();
+  Bar.reopenClass({
+    method() {
+      this._super();
+      calls.push('bar');
+    }
+  });
 
-  assert.deepEqual(calls, [
-    'super-super-method',
-    'super-method',
-    'method'
-  ], 'chain of prototype methods called with super');
+  class Baz extends Bar {
+    static method() {
+      super.method();
+      calls.push('baz');
+    }
+  }
+
+  let Qux = Baz.extend();
+  Qux.reopenClass({
+    method() {
+      this._super();
+      calls.push('qux');
+    }
+  });
+
+  let Quux = Qux.extend();
+  Quux.reopenClass({
+    method() {
+      this._super();
+      calls.push('quux');
+    }
+  });
+
+  class Corge extends Quux {
+    static method() {
+      super.method();
+      calls.push('corge');
+    }
+  }
+
+  let callValues = ['foo', 'bar', 'baz', 'qux', 'quux', 'corge'];
+
+  [Foo, Bar, Baz, Qux, Quux, Corge].forEach((Class, index) => {
+    calls = [];
+    Class.method();
+
+    assert.deepEqual(calls, callValues.slice(0, index + 1), 'chain of static methods called with super');
+  });
+});
+
+QUnit.test('reopen and reopenClass on native class do not work', function(assert) {
+  class Foo extends EmberObject {}
+
+  assert.throws(
+    () => {
+      Foo.reopen({
+        foo() {
+          // do nothing
+        }
+      });
+    },
+    /You cannot reopen Foo because it was defined with native class syntax/
+  );
+
+  assert.throws(
+    () => {
+      Foo.reopenClass({
+        foo() {
+          // do nothing
+        }
+      });
+    },
+    /You cannot reopen Foo because it was defined with native class syntax/
+  );
+});
+
+QUnit.test('reopen and reopenClass on native class do not work after .extend', function(assert) {
+  class Foo extends EmberObject {}
+
+  let Bar = Foo.extend();
+
+  class Baz extends Bar {}
+
+  assert.throws(
+    () => {
+      Baz.reopen({
+        foo() {
+          // do nothing
+        }
+      });
+    },
+    /You cannot reopen Baz because it was defined with native class syntax/
+  );
+
+  assert.throws(
+    () => {
+      Baz.reopenClass({
+        foo() {
+          // do nothing
+        }
+      });
+    },
+    /You cannot reopen Baz because it was defined with native class syntax/
+  );
 });
 
 QUnit.test('using mixins', function(assert) {
@@ -123,14 +259,15 @@ QUnit.test('extending an ES subclass of EmberObject', function(assert) {
   assert.deepEqual(calls, ['constructor', 'init'], 'constructor then init called (new)');
 });
 
-// TODO: Needs to be fixed. Currently only `init` is called.
-QUnit.skip('calling extend on an ES subclass of EmberObject', function(assert) {
+QUnit.test('calling extend on an ES subclass of EmberObject', function(assert) {
   let calls = [];
 
   class SubEmberObject extends EmberObject {
     constructor() {
-      calls.push('constructor');
+      calls.push('before constructor');
       super(...arguments);
+      calls.push('after constructor');
+      this.foo = 123;
     }
 
     init() {
@@ -142,9 +279,17 @@ QUnit.skip('calling extend on an ES subclass of EmberObject', function(assert) {
   let MyObject = SubEmberObject.extend({});
 
   MyObject.create();
-  assert.deepEqual(calls, ['constructor', 'init'], 'constructor then init called (create)');
+  assert.deepEqual(calls, ['before constructor', 'init', 'after constructor'], 'constructor then init called (create)');
 
   calls = [];
   new MyObject();
-  assert.deepEqual(calls, ['constructor', 'init'], 'constructor then init called (new)');
+  assert.deepEqual(calls, ['before constructor', 'init', 'after constructor'], 'constructor then init called (new)');
+
+  let obj = MyObject.create({
+    foo: 456,
+    bar: 789
+  });
+
+  assert.equal(obj.foo, 123, 'sets class fields on instance correctly');
+  assert.equal(obj.bar, 789, 'sets passed in properties on instance correctly');
 });