Wrapperless dart:html and friends

lib/runtime/dart/_runtime.js

 dart_library.library('dart/_runtime', null, /* Imports */[
 ], /* Lazy imports */[
   'dart/core',
   'dart/_interceptors',
   'dart/_js_helper',
   'dart/async',
   'dart/collection'
 ], function(exports, core, _interceptors, _js_helper, async, collection) {
   'use strict';
   function mixin(base, ...mixins) {
@@ skipping 112 matching lines @@
     });
   }
   function _setConstructorSignature(f, sigF) {
     return defineMemoizedGetter(f, _constructorSig, sigF);
   }
   function _setStaticSignature(f, sigF) {
     return defineMemoizedGetter(f, _staticSig, sigF);
   }
   function _setStaticTypes(f, names) {
     for (let name of names) {
+      if (!f[name]) continue;
       tagMemoized(f[name], function() {
         let parts = f[_staticSig][name];
         return definiteFunctionType.apply(null, parts);
       });
     }
   }
   function setSignature(f, signature) {
     let constructors = 'constructors' in signature ? signature.constructors : () => ({});
     let methods = 'methods' in signature ? signature.methods : () => ({});
     let statics = 'statics' in signature ? signature.statics : () => ({});
     let names = 'names' in signature ? signature.names : [];
     _setConstructorSignature(f, constructors);
     _setMethodSignature(f, methods);
     _setStaticSignature(f, statics);
     _setStaticTypes(f, names);
     tagMemoized(f, () => core.Type);
   }
   function hasMethod(obj, name) {
     return getMethodType(obj, name) !== void 0;
   }
   function virtualField(subclass, fieldName) {
     let prop = getOwnPropertyDescriptor(subclass.prototype, fieldName);
     if (prop) return;
-    let symbol = Symbol(subclass.name + '.' + fieldName);
+    let symbol = Symbol(subclass.name + '.' + fieldName.toString());
     defineProperty(subclass.prototype, fieldName, {
       get: function() {
         return this[symbol];
       },
       set: function(x) {
         this[symbol] = x;
       }
     });
   }
   function defineNamedConstructor(clazz, name) {
     let proto = clazz.prototype;
     let initMethod = proto[name];
     let ctor = function() {
       return initMethod.apply(this, arguments);
     };
     ctor.prototype = proto;
     defineProperty(clazz, name, {value: ctor, configurable: true});
   }
   const _extensionType = Symbol("extensionType");
   function getExtensionType(obj) {
     return obj[_extensionType];
   }
   const dartx = {};
   function getExtensionSymbol(name) {
     let sym = dartx[name];
-    if (!sym) dartx[name] = sym = Symbol('dartx.' + name);
+    if (!sym) dartx[name] = sym = Symbol('dartx.' + name.toString());
     return sym;
   }
   function defineExtensionNames(names) {
     return names.forEach(getExtensionSymbol);
   }
   function _installProperties(jsProto, extProto) {
     if (extProto !== core.Object.prototype && extProto !== jsProto) {
       _installProperties(jsProto, extProto.__proto__);
     }
     copyTheseProperties(jsProto, extProto, getOwnPropertySymbols(extProto));
   }
   function registerExtension(jsType, dartExtType) {
+    if (!jsType) return;
     let extProto = dartExtType.prototype;
     let jsProto = jsType.prototype;
-    assert_(jsProto[_extensionType] === void 0);
     jsProto[_extensionType] = dartExtType;
     _installProperties(jsProto, extProto);
     let originalSigFn = getOwnPropertyDescriptor(dartExtType, _methodSig).get;
     assert_(originalSigFn);
     defineMemoizedGetter(jsType, _methodSig, originalSigFn);
   }
   function defineExtensionMembers(type, methodNames) {
     let proto = type.prototype;
     for (let name of methodNames) {
       let method = getOwnPropertyDescriptor(proto, name);
+      if (!method) continue;
       defineProperty(proto, getExtensionSymbol(name), method);
     }
     let originalSigFn = getOwnPropertyDescriptor(type, _methodSig).get;
     defineMemoizedGetter(type, _methodSig, function() {
       let sig = originalSigFn();
       for (let name of methodNames) {
         sig[getExtensionSymbol(name)] = sig[name];
       }
       return sig;
     });
@@ skipping 1097 matching lines @@
   exports.copyProperties = copyProperties;
   exports.export = export_;
   exports.defineLazyClass = defineLazyClass;
   exports.defineLazyProperties = defineLazyProperties;
   exports.defineLazyClassGeneric = defineLazyClassGeneric;
   exports.as = as_;
   exports.is = is_;
   exports.global = global_;
   exports.JsSymbol = JsSymbol;
 });