Roll Observatory deps (charted -> ^0.3.0)

packages/dart_style/test/formatter_test.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.
 
 @TestOn("vm")
 library dart_style.test.formatter_test;
 
 import 'dart:io';
 import 'dart:mirrors';
 
@@ skipping 131 matching lines @@
       .path);
 
   var entries = new Directory(p.join(testDir, name))
       .listSync(recursive: true, followLinks: false);
   for (var entry in entries) {
     if (!entry.path.endsWith(".stmt") && !entry.path.endsWith(".unit")) {
       continue;
     }
 
     group("$name ${p.basename(entry.path)}", () {
-      var lines = (entry as File).readAsLinesSync();
+      // Explicitly create a File, in case the entry is a Link.
+      var lines = new File(entry.path).readAsLinesSync();
 
       // The first line may have a "|" to indicate the page width.
       var pageWidth;
       if (lines[0].endsWith("|")) {
         pageWidth = lines[0].indexOf("|");
         lines = lines.skip(1).toList();
       }
 
       var i = 0;
       while (i < lines.length) {
@@ skipping 37 matching lines @@
               new DartFormatter(pageWidth: pageWidth, indent: leadingIndent);
 
           var actual = formatter.formatSource(inputCode);
 
           // The test files always put a newline at the end of the expectation.
           // Statements from the formatter (correctly) don't have that, so add
           // one to line up with the expected result.
           var actualText = actual.text;
           if (!isCompilationUnit) actualText += "\n";
 
-          expect(actualText, equals(expected.text));
+          // Fail with an explicit message because it's easier to read than
+          // the matcher output.
+          if (actualText != expected.text) {
+            fail("Formatting did not match expectation. Expected:\n"
+                "${expected.text}\nActual:\n$actualText");
+          }
+
           expect(actual.selectionStart, equals(expected.selectionStart));
           expect(actual.selectionLength, equals(expected.selectionLength));
         });
       }
     });
   }
 }
 
 /// Given a source string that contains ‹ and › to indicate a selection, returns
 /// a [SourceCode] with the text (with the selection markers removed) and the
 /// correct selection range.
 SourceCode _extractSelection(String source, {bool isCompilationUnit: false}) {
   var start = source.indexOf("‹");
   source = source.replaceAll("‹", "");
 
   var end = source.indexOf("›");
   source = source.replaceAll("›", "");
 
   return new SourceCode(source,
       isCompilationUnit: isCompilationUnit,
       selectionStart: start == -1 ? null : start,
       selectionLength: end == -1 ? null : end - start);
 }