Custom formatter cleanup Fix case where displaying a class constructor generated unreadable huge ou…

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.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.
 
 /// This library defines runtime operations on objects used by the code
 /// generator.
 part of dart._runtime;
 
 class InvocationImpl extends Invocation {
   final Symbol memberName;
@@ skipping 864 matching lines @@
 
 @JSExportName('toString')
 String _toString(obj) {
   if (obj == null) return "null";
 
   var extension = getExtensionType(obj);
   if (extension != null) {
     return JS('String', '#[dartx.toString]()', obj);
   }
   if (JS('bool', 'typeof # == "function"', obj)) {
-    return JS(
-        'String', r'"Closure: " + # + " from: " + #', getReifiedType(obj), obj);
+    var type = getReifiedType(obj);

[Jacob, 2017/02/20 22:48:54]

this is the most questionable part of the CL. Perhaps there is a simple fix to
getReifiedType so that it doesn't
return a bogus value for this case?

[vsm, 2017/02/21 14:33:00]

I don't think this *if* clause was intended to handle types at all - just Dart
functions.

Can we do something like if (istype) return typeName?  Not sure we have a could
istype function, but we should be able to refactor dart.typeName is types.dart.

[Jacob, 2017/02/21 17:41:15]

That is much better.
Added an isType method and returned the type name in that case.

+    var sourceCode = JS('String', 'Object.toString.call(#)', obj);
+    if (sourceCode.startsWith('class ')) {
+      // Display "class Foo" instead of claiming that we have a closure where from
+      // is the entire source code of the class which is overly verbose and very
+      // confusing.
+      // TODO(jacobr): getReifiedType appears to be completely bogus in this case.
+      return sourceCode.split(' ').take(2).join(' ');
+    }
+    return JS('String', r'"Closure: " + # + " from: " + #', type, obj);
   }
   // TODO(jmesserly): restore this faster path once ES Symbol is treated as
   // an extension type (and thus hits the above code path).
   // See https://github.com/dart-lang/sdk/issues/28323
   // return JS('', '"" + #', obj);
   return JS('String', '#.toString()', obj);
 }
 
 // TODO(jmesserly): is the argument type verified statically?
 noSuchMethod(obj, Invocation invocation) {
@@ skipping 70 matching lines @@
     name = '+' + name;
   }
   return name;
 }
 
 /// Emulates the implicit "loadLibrary" function provided by a deferred library.
 ///
 /// Libraries are not actually deferred in DDC, so this just returns a future
 /// that completes immediately.
 Future loadLibrary() => new Future.value();