implement mixins in subtype checks, more codegen fixes

lib/runtime/dart_runtime.js

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 var dart, _js_helper;
 (function (dart) {
   'use strict';
 
   let defineProperty = Object.defineProperty;
   let getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
@@ skipping 78 matching lines @@
     return checkAndCall(obj.set, obj, [index, value], '[]=');
   }
   dart.dsetindex = dindex;
 
   function dbinary(left, op, right) {
     return checkAndCall(left[op], left, [right], op);
   }
   dart.dbinary = dbinary;
 
   function cast(obj, type) {
-    //TODO(vsm): handle non-nullable types
+    // TODO(vsm): handle non-nullable types
     if (obj == null) return obj;
     let actual = getRuntimeType(obj);
     if (isSubtype(actual, type)) return obj;
     throw new _js_helper.CastErrorImplementation(actual, type);
   }
   dart.as = cast;
 
   /**
    * Returns the runtime type of obj. This is the same as `obj.runtimeType`
    * but will not call an overridden getter.
@@ skipping 72 matching lines @@
 
     if (t2 == core.Object) return true;
     if (t1 == core.Object) return false;
 
     // "Traditional" name-based subtype check.
     if (isClassSubType(t1, t2)) {
       return true;
     }
 
     // Function subtyping.
-    // TODO(jmesserly): implement.
+    // TODO(jmesserly): implement this properly.
+    if (isClassSubType(t1, core.Function) &&
+        isClassSubType(t2, core.Function)) {
+      return true;
+    }
     return false;
   }
 
   function safeGetOwnProperty(obj, name) {
     var desc = getOwnPropertyDescriptor(obj, name);
     if (desc) return desc.value;
   }
 
   function isClassSubType(t1, t2) {
     // We support Dart's covariant generics with the caveat that we do not
@@ skipping 25 matching lines @@
         if (!isSubtype(typeArguments1[i], typeArguments2[i])) {
           return false;
         }
       }
       return true;
     }
 
     // Check superclass.
     if (isClassSubType(t1.__proto__, t2)) return true;
 
+    // Check mixins.
+    let mixins = safeGetOwnProperty(t1, dart.mixins);
+    if (mixins) {
+      for (let m1 of mixins) {
+        // TODO(jmesserly): remove the != null check once we can load core libs.
+        if (m1 != null && isClassSubType(m1, t2)) return true;
+      }
+    }
+
     // Check interfaces.
     let getInterfaces = safeGetOwnProperty(t1, dart.implements);
     if (getInterfaces) {
       for (let i1 of getInterfaces()) {
         // TODO(jmesserly): remove the != null check once we can load core libs.
         if (i1 != null && isClassSubType(i1, t2)) return true;
       }
     }
 
     return false;
@@ skipping 116 matching lines @@
     let mixins = Array.prototype.slice.call(arguments, 1);
 
     // Create a class that will hold all of the mixin methods.
     class Mixin extends base {
       // Initializer method: run mixin initializers, then the base.
       [base.name](/*...args*/) {
         // Run mixin initializers. They cannot have arguments.
         // Run them backwards so most-derived mixin is initialized first.
         for (let i = mixins.length - 1; i >= 0; i--) {
           let mixin = mixins[i];
-          mixin.prototype[mixin.name].call(this);
+          let init = mixin.prototype[mixin.name];
+          if (init) init.call(this);
         }
         // Run base initializer.
-        base.prototype[base.name].apply(this, arguments);
+        let init = base.prototype[base.name];
+        if (init) init.apply(this, arguments);
       }
     }
     // Copy each mixin's methods, with later ones overwriting earlier entries.
     for (let m of mixins) {
       copyProperties(Mixin.prototype, m.prototype);
     }
     // Save mixins for reflection
     Mixin[dart.mixins] = mixins;
     return Mixin;
   }
@@ skipping 106 matching lines @@
   // of some sort, assuming we keep around `dynamic` at runtime.
   dart.dynamic = { toString() { return 'dynamic'; } };
 
   dart.JsSymbol = Symbol;
 
   // TODO(jmesserly): hack to bootstrap the SDK
   _js_helper = _js_helper || {};
   _js_helper.checkNum = notNull;
 
 })(dart || (dart = {}));