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

Index: pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
diff --git a/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart b/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
index 6f4236c65a8f00db2fbe669bfa4c72b835f1a026..f494983558e7d36edd0d9f02b8c3c324ac9fbbe4 100644
--- a/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
+++ b/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
@@ -882,8 +882,16 @@ String _toString(obj) {
     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).