More gracefully handle load errors.

lib/src/runner/reporter/compact.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 test.runner.reporter.compact;
 
 import 'dart:async';
 import 'dart:io';
+import 'dart:isolate';
 
 import '../../backend/live_test.dart';
 import '../../backend/state.dart';
 import '../../backend/suite.dart';
 import '../../utils.dart';
 import '../engine.dart';
+import '../load_exception.dart';
 
 /// The maximum console line length.
 ///
 /// Lines longer than this will be cropped.
 const _lineLength = 100;
 
 /// A reporter that prints test results to the console in a single
 /// continuously-updating line.
 class CompactReporter {
+  /// Whether the reporter should emit terminal color escapes.
+  final bool _color;
+
   /// The terminal escape for green text, or the empty string if this is Windows
   /// or not outputting to a terminal.
   final String _green;
 
   /// The terminal escape for red text, or the empty string if this is Windows
   /// or not outputting to a terminal.
   final String _red;
 
   /// The terminal escape for removing test coloring, or the empty string if
   /// this is Windows or not outputting to a terminal.
@@ skipping 37 matching lines @@
 
   /// Creates a [ConsoleReporter] that will run all tests in [suites].
   ///
   /// If [color] is `true`, this will use terminal colors; if it's `false`, it
   /// won't.
   CompactReporter(Iterable<Suite> suites, {int concurrency, bool color: true})
       : _multiplePaths = suites.map((suite) => suite.path).toSet().length > 1,
         _multiplePlatforms =
             suites.map((suite) => suite.platform).toSet().length > 1,
         _engine = new Engine(suites, concurrency: concurrency),
+        _color = color,
         _green = color ? '\u001b[32m' : '',
         _red = color ? '\u001b[31m' : '',
         _noColor = color ? '\u001b[0m' : '' {
     _engine.onTestStarted.listen((liveTest) {
       if (_active.isEmpty) _progressLine(_description(liveTest));
       _active.add(liveTest);
       _printedNewline = false;
 
       liveTest.onStateChange.listen((state) {
         if (state.status != Status.complete) return;
@@ skipping 16 matching lines @@
         _printedNewline = false;
       });
 
       liveTest.onError.listen((error) {
         if (liveTest.state.status != Status.complete) return;
 
         _progressLine(_description(liveTest));
         if (!_printedNewline) print('');
         _printedNewline = true;
 
-        print(indent(error.error.toString()));
-        print(indent(terseChain(error.stackTrace).toString()));
+        if (error.error is! LoadException) {
+          print(indent(error.error.toString()));
+          print(indent(terseChain(error.stackTrace).toString()));
+          return;
+        }
+
+        print(indent(error.error.toString(color: _color)));
+
+        // Only print stack traces for load errors that come from the user's code.
+        if (error.error.innerError is! IOException &&
+            error.error.innerError is! IsolateSpawnException &&
+            error.error.innerError is! FormatException &&
+            error.error.innerError is! String) {
+          print(indent(terseChain(error.stackTrace).toString()));
+        }
       });
 
       liveTest.onPrint.listen((line) {
         _progressLine(_description(liveTest));
         if (!_printedNewline) print('');
         _printedNewline = true;
 
         print(line);
       });
     });
@@ skipping 110 matching lines @@
       name = "${liveTest.suite.path}: $name";
     }
 
     if (_multiplePlatforms && liveTest.suite.platform != null) {
       name = "[${liveTest.suite.platform}] $name";
     }
 
     return name;
   }
 }