fix #30290, assertion messages that contain `yield`

pkg/dev_compiler/lib/src/compiler/code_generator.dart

 // 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.
 
 import 'dart:collection' show HashMap, HashSet;
 import 'dart:math' show min, max;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 3939 matching lines @@
   JS.EmptyStatement visitEmptyStatement(EmptyStatement node) =>
       new JS.EmptyStatement();
 
   @override
   JS.Statement visitAssertStatement(AssertStatement node) {
     // TODO(jmesserly): only emit in checked mode.
     var condition = node.condition;
     var conditionType = condition.staticType;
     JS.Expression jsCondition = _visit(condition);
 
-    var assertHelper = 'assert';
     if (conditionType is FunctionType &&
         conditionType.parameters.isEmpty &&
         conditionType.returnType == types.boolType) {
-      jsCondition = new JS.Call(jsCondition, []);
+      jsCondition = _callHelper('test(#())', jsCondition);
     } else if (conditionType != types.boolType) {
-      assertHelper = 'dassert';
+      jsCondition = _callHelper('dassert(#)', jsCondition);
+    } else if (isNullable(condition)) {
+      jsCondition = _callHelper('test(#)', jsCondition);
     }
-    var args = [jsCondition];
-    if (node.message != null) {
-      args.add(js.call('() => #', [_visit(node.message)]));
-    }
-    return _callHelperStatement('$assertHelper(#);', [args]);
+    return js.statement(' if (!#) #.assertFailed(#);', [
+      jsCondition,
+      _runtimeModule,
+      node.message != null ? [_visit(node.message)] : []
+    ]);
   }
 
   @override
   JS.Statement visitReturnStatement(ReturnStatement node) {
     var e = node.expression;
     if (e == null) return new JS.Return();
     return _visit<JS.Expression>(e).toReturn();
   }
 
   @override
@@ skipping 1991 matching lines @@
   if (targetIdentifier.staticElement is! PrefixElement) return false;
   var prefix = targetIdentifier.staticElement as PrefixElement;
 
   // The library the prefix is referring to must come from a deferred import.
   var containingLibrary = resolutionMap
       .elementDeclaredByCompilationUnit(target.root as CompilationUnit)
       .library;
   var imports = containingLibrary.getImportsWithPrefix(prefix);
   return imports.length == 1 && imports[0].isDeferred;
 }