Use failedAt in more places (js_emitter)

pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart

 // Copyright (c) 2014, 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.
 
 library dart2js.js_emitter.program_builder;
 
 import 'dart:io';
 import 'dart:convert' show JSON;
 
 import '../../closure.dart' show ClosureTask, ClosureFieldElement;
@@ skipping 209 matching lines @@
     collector.outputClassLists
         .forEach((OutputUnit _, List<ClassEntity> classes) {
       classes.forEach(_buildClass);
     });
 
     // Resolve the superclass references after we've processed all the classes.
     _classes.forEach((ClassEntity cls, Class c) {
       ClassEntity superclass = _elementEnvironment.getSuperClass(cls);
       if (superclass != null) {
         c.setSuperclass(_classes[superclass]);
-        assert(invariant(cls, c.superclass != null,
-            message: "No Class for has been created for superclass "
+        assert(
+            c.superclass != null,
+            failedAt(
+                cls,
+                "No Class for has been created for superclass "
                 "${superclass} of $c."));
       }
       if (c is MixinApplication) {
         c.setMixinClass(_classes[computeMixinClass(cls)]);
         assert(c.mixinClass != null);
       }
     });
 
     List<Class> nativeClasses = collector.nativeClassesAndSubclasses
         .map((ClassEntity classElement) => _classes[classElement])
@@ skipping 444 matching lines @@
         _task,
         _namer,
         _nativeData,
         _rtiChecks,
         _rtiEncoder,
         _rtiNeed,
         _rtiSubstitutions,
         _jsInteropAnalysis);
 
     void visitMember(ClassElement enclosing, MemberElement member) {
-      assert(invariant(element, member.isDeclaration));
-      assert(invariant(element, element == enclosing));
+      assert(member.isDeclaration, failedAt(element));
+      assert(element == enclosing, failedAt(element));
 
       if (Elements.isNonAbstractInstanceMember(member)) {
         // TODO(herhut): Remove once _buildMethod can no longer return null.
         Method method = _buildMethod(member);
         if (method != null) methods.add(method);
       }
       if (member.isGetter || member.isField) {
         Map<Selector, SelectorConstraints> selectors =
             _worldBuilder.invocationsByName(member.name);
         if (selectors != null && !selectors.isEmpty) {
@@ skipping 189 matching lines @@
         // Careful with operators.
         canTearOff = _worldBuilder.hasInvokedGetter(element, _closedWorld) ||
             (canBeReflected && !element.isOperator);
         assert(canTearOff ||
             !_worldBuilder.methodsNeedingSuperGetter.contains(element));
         tearOffName = _namer.getterForElement(element);
       }
     }
 
     if (canTearOff) {
-      assert(invariant(element, !element.isGenerativeConstructor));
-      assert(invariant(element, !element.isGenerativeConstructorBody));
-      assert(invariant(element, !element.isConstructor));
+      assert(!element.isGenerativeConstructor, failedAt(element));
+      assert(!element.isGenerativeConstructorBody, failedAt(element));
+      assert(!element.isConstructor, failedAt(element));
     }
 
     js.Name callName = null;
     if (canTearOff) {
       Selector callSelector =
           new Selector.fromElement(element).toCallSelector();
       callName = _namer.invocationName(callSelector);
     }
 
     ResolutionDartType memberType;
@@ skipping 118 matching lines @@
       {bool visitStatics, bool isHolderInterceptedClass: false}) {
     List<Field> fields = <Field>[];
     new FieldVisitor(_options, _worldBuilder, _nativeData, _mirrorsData, _namer,
             _closedWorld)
         .visitFields(holder, visitStatics, (FieldElement field,
             js.Name name,
             js.Name accessorName,
             bool needsGetter,
             bool needsSetter,
             bool needsCheckedSetter) {
-      assert(invariant(field, field.isDeclaration));
+      assert(field.isDeclaration, failedAt(field));
 
       int getterFlags = 0;
       if (needsGetter) {
         if (visitStatics ||
             !_interceptorData.fieldHasInterceptedGetter(field)) {
           getterFlags = 1;
         } else {
           getterFlags += 2;
           // TODO(sra): 'isInterceptedClass' might not be the correct test
           // for methods forced to use the interceptor convention because
@@ skipping 115 matching lines @@
       Constant constant = new Constant(name, holder, constantValue);
       _constants[constantValue] = constant;
     }
   }
 
   Holder _registerStaticStateHolder() {
     return _registry.registerHolder(_namer.staticStateHolder,
         isStaticStateHolder: true);
   }
 }