Gracefully handle tests that print.

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 unittest.runner.reporter.compact;
 
 import 'dart:async';
 import 'dart:io';
 
 import '../../backend/live_test.dart';
@@ skipping 54 matching lines @@
   /// If [color] is `true`, this will use terminal colors; if it's `false`, it
   /// won't.
   CompactReporter(Iterable<Suite> suites, {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),
         _green = color ? '\u001b[32m' : '',
         _red = color ? '\u001b[31m' : '',
         _noColor = color ? '\u001b[0m' : '' {
+    // Whether a newline has been printed since the last progress line.
+    var printedNewline = false;
     _engine.onTestStarted.listen((liveTest) {
       _progressLine(_description(liveTest));
       liveTest.onStateChange.listen((state) {
         if (state.status != Status.complete) return;
         if (state.result == Result.success) {
           _passed.add(liveTest);
         } else {
           _passed.remove(liveTest);
           _failed.add(liveTest);
         }
         _progressLine(_description(liveTest));
+        printedNewline = false;
       });
 
       liveTest.onError.listen((error) {
         if (liveTest.state.status != Status.complete) return;
 
         _progressLine(_description(liveTest));
-        print('');
+        if (!printedNewline) print('');
+        printedNewline = true;
+
         print(indent(error.error.toString()));
         print(indent(terseChain(error.stackTrace).toString()));
       });
+
+      liveTest.onPrint.listen((line) {
+        _progressLine(_description(liveTest));
+        if (!printedNewline) print('');
+        printedNewline = true;
+
+        print(line);
+      });
     });
   }
 
   /// Runs all tests in all provided suites.
   ///
   /// This returns `true` if all tests succeed, and `false` otherwise. It will
   /// only return once all tests have finished running.
   Future<bool> run() {
     if (_stopwatch.isRunning) {
       throw new StateError("CompactReporter.run() may not be called more than "
@@ skipping 21 matching lines @@
 
   /// Signals that the caller is done with any test output and the reporter
   /// should release any resources it has allocated.
   Future close() => _engine.close();
 
   /// Prints a line representing the current state of the tests.
   ///
   /// [message] goes after the progress report, and may be truncated to fit the
   /// entire line within [_lineLength]. If [color] is passed, it's used as the
   /// color for [message].
-  void _progressLine(String message, {String color}) {
+  bool _progressLine(String message, {String color}) {
     // Print nothing if nothing has changed since the last progress line.
     if (_passed.length == _lastProgressPassed &&
         _failed.length == _lastProgressFailed &&
         message == _lastProgressMessage) {
-      return;
+      return false;
     }
 
     _lastProgressPassed = _passed.length;
     _lastProgressFailed = _failed.length;
     _lastProgressMessage = message;
 
     if (color == null) color = '';
     var duration = _stopwatch.elapsed;
     var buffer = new StringBuffer();
 
@@ skipping 20 matching lines @@
     var nonVisible = 1 + _green.length + _noColor.length + color.length +
         (_failed.isEmpty ? 0 : _red.length + _noColor.length);
     var length = buffer.length - nonVisible;
     buffer.write(truncate(message, _lineLength - length));
     buffer.write(_noColor);
 
     // Pad the rest of the line so that it looks erased.
     length = buffer.length - nonVisible - _noColor.length;
     buffer.write(' ' * (_lineLength - length));
     stdout.write(buffer.toString());
+    return true;
   }
 
   /// Returns a representation of [duration] as `MM:SS`.
   String _timeString(Duration duration) {
     return "${duration.inMinutes.toString().padLeft(2, '0')}:"
         "${(duration.inSeconds % 60).toString().padLeft(2, '0')}";
   }
 
   /// Returns a description of [liveTest].
   ///
   /// This differs from the test's own description in that it may also include
   /// the suite's name.
   String _description(LiveTest liveTest) {
     var name = liveTest.test.name;
 
     if (_multiplePaths && liveTest.suite.path != null) {
       name = "${liveTest.suite.path}: $name";
     }
 
     if (_multiplePlatforms && liveTest.suite.platform != null) {
       name = "[${liveTest.suite.platform}] $name";
     }
 
     return name;
   }
 }