maxspanlength setter

tool/input_sdk/private/debugger.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.
 
 library dart._debugger;
 
 import 'dart:_foreign_helper' show JS;
 import 'dart:_runtime' as dart;
 import 'dart:core';
 import 'dart:collection';
@@ skipping 12 matching lines @@
 /// We'd like this to be an enum, but we can't because it's a dev_compiler bug.
 class JsonMLConfig {
   const JsonMLConfig(this.name);
 
   final String name;
   static const none = const JsonMLConfig("none");
   static const skipDart = const JsonMLConfig("skipDart");
   static const keyToString = const JsonMLConfig("keyToString");
 }
 
-int maxSpanLength = 100;
+int _maxSpanLength = 100;
 
 var _devtoolsFormatter = new JsonMLFormatter(new DartFormatter());
 
 String _typeof(object) => JS('String', 'typeof #', object);
 
 List<String> getOwnPropertyNames(object) => JS('List<String>',
     'dart.list(Object.getOwnPropertyNames(#), #)', object, String);
 
 List getOwnPropertySymbols(object) =>
     JS('List', 'Object.getOwnPropertySymbols(#)', object);
@@ skipping 169 matching lines @@
 class JsonMLFormatter {
   // TODO(jacobr): define a SimpleFormatter base class that DartFormatter
   // implements if we decide to use this class elsewhere. We specify that the
   // type is DartFormatter here purely to get type checking benefits not because
   // this class is really intended to only support instances of type
   // DartFormatter.
   DartFormatter _simpleFormatter;
 
   JsonMLFormatter(this._simpleFormatter);
 
+  set maxSpanLength(int spanLength) => _maxSpanLength = spanLength;

[Jacob, 2016/06/28 18:59:11]

why is this needed?
Having a public field should have the same externally visible effect.

[bmilligan, 2016/06/28 20:12:31]

I don't have access to the debugger.dart file, but only the JsonMLFormatter.
Setting devtoolsFormatters[0].maxSpanLength = 6 for example doesn't result in
any change. If I add this setter, though, that command works. Is there a
different way to access the public variable without the setter?

[Jacob, 2016/06/28 20:36:37]

Oh clever. I like this hack. I missed this was inside the JsonMLFormatter class
before.
Just add a comment explaining what you described in your comment so it is clear
that this method was added purely for testing purposes.
Otherwise it would seem to be a bug that you have a instance setters that sets
the value of a top level field.
Another option is to make the property name intentionally ugly so it is really
clear what is going on. E.g.

void setMaxSpanLengthForTestingOnly(int spanLength) => _maxSpanLength =
spanLength;

[bmilligan, 2016/06/28 20:45:08]

Done.

+
   header(object, config) {
     if (config == JsonMLConfig.skipDart || isNativeJavaScriptObject(object)) {
       return null;
     }
 
     var c = _simpleFormatter.preview(object);
     if (c == null) return null;
 
     if (config == JsonMLConfig.keyToString) {
       c = object.toString();
@@ skipping 393 matching lines @@
   }
 
   bool hasChildren(object) => true;
 
   List<NameValuePair> children(object) => childrenHelper(object);
 }
 
 List<NameValuePair> childrenHelper(IterableSpan span) {
   var length = span.end - span.start;
   var ret = new List<NameValuePair>();
-  if (length <= maxSpanLength) {
+  if (length <= _maxSpanLength) {
     for (var i = span.start; i < span.end; i++) {
       /// TODO(bmilligan): Stop using elementAt if it becomes a performance
       /// bottleneck in the future.
       ret.add(new NameValuePair(
           name: i.toString(), value: span.iterable.elementAt(i)));
     }
   } else {
     /// Using length - .5, a list of length 10000 results in a
     /// maxPowerOfSubsetSize of 1, so the list will be broken up into 100,
     /// 100-length subsets. A list of length 10001 results in a
     /// maxPowerOfSubsetSize of 2, so the list will be broken up into 1
     /// 10000-length subset and 1 1-length subset.
     var maxPowerOfSubsetSize =
-        (log(length - .5) / log(maxSpanLength)).truncate();
-    var subsetSize = pow(maxSpanLength, maxPowerOfSubsetSize);
+        (log(length - .5) / log(_maxSpanLength)).truncate();
+    var subsetSize = pow(_maxSpanLength, maxPowerOfSubsetSize);
     for (var i = span.start; i < span.end; i += subsetSize) {
       var endIndex = min(span.end, subsetSize + i);
       if (endIndex - i == 1)
         ret.add(new NameValuePair(
             name: i.toString(), value: span.iterable.elementAt(i)));
       else {
         var entryWrapper =
             new IterableSpan(start: i, end: endIndex, iterable: span.iterable);
         ret.add(new NameValuePair(
             name: '[${i}...${endIndex - 1}]',
             value: entryWrapper,
             hideName: true));
       }
     }
   }
   return ret;
 }
 
 /// This entry point is automatically invoked by the code generated by
 /// Dart Dev Compiler
 registerDevtoolsFormatter() {
   var formatters = [_devtoolsFormatter];
   JS('', 'dart.global.devtoolsFormatters = #', formatters);
 }