Tighten types in test.dart even more.

tools/testing/dart/record_and_replay.dart

 // Copyright (c) 2012, 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 record_and_replay;
 
 import 'dart:io';
 import 'dart:convert';
 
 import 'path.dart';
@@ skipping 73 matching lines @@
 class TestCaseOutputArchive {
   Map<String, Map> _commandOutputRecordings;
   String _cwd;
 
   TestCaseOutputArchive() {
     _cwd = Directory.current.path;
   }
 
   void loadFromPath(Path recordingPath) {
     var file = new File(recordingPath.toNativePath());
-    var commandRecordings = JSON.decode(file.readAsStringSync());
+    var commandRecordings = JSON.decode(file.readAsStringSync())
+        as List<Map<String, Map<String, dynamic>>>;

[Siggi Cherem (dart-lang), 2017/05/30 20:48:39]

same here: looks to me like this would fail in strong mode.

[Bob Nystrom, 2017/05/30 21:01:46]

Done.

     _commandOutputRecordings = {};
     for (var commandRecording in commandRecordings) {
-      var key = _indexKey(commandRecording['command']['executable'],
-          commandRecording['command']['arguments'].join(' '));
+      var key = _indexKey(commandRecording['command']['executable'] as String,
+          (commandRecording['command']['arguments'] as List).join(' '));
       _commandOutputRecordings[key] = commandRecording['command_output'];
     }
   }
 
   CommandOutput outputOf(ProcessCommand command) {
     // Convert arguments from absolute to relative paths (relative to the dart
     // directory) because the absolute path on the machine where we record
     // may be different from the absolute path on the machine where we execute
     // the commands.
     var arguments = makePathsRelativeToDart(_cwd, command.arguments);
 
     var key = _indexKey(command.executable, arguments.join(' '));
     var command_output = _commandOutputRecordings[key];
     if (command_output == null) {
       print("Sorry, but there is no command output for ${command.displayName}"
           " ($command)");
       exit(42);
     }
 
-    double seconds = command_output['duration'];
+    double seconds = command_output['duration'] as double;
     var duration = new Duration(
         seconds: seconds.round(), milliseconds: (seconds / 1000).round());
     var commandOutput = createCommandOutput(
         command,
-        command_output['exit_code'],
-        command_output['did_timeout'],
-        UTF8.encode(command_output['stdout']),
-        UTF8.encode(command_output['stderr']),
+        command_output['exit_code'] as int,
+        command_output['did_timeout'] as bool,
+        UTF8.encode(command_output['stdout'] as String),
+        UTF8.encode(command_output['stderr'] as String),
         duration,
         false);
     return commandOutput;
   }
 
   String _indexKey(String executable, String arguments) {
     return "${executable}__$arguments";
   }
 }