Fix all strong-mode errors and warnings.

lib/src/runner/configuration/args.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:boolean_selector/boolean_selector.dart';
 
 import '../../backend/test_platform.dart';
@@ skipping 113 matching lines @@
 ///
 /// This is used to provide access to the arg results across helper methods.
 class _Parser {
   /// The parsed options.
   final ArgResults _options;
 
   _Parser(List<String> args) : _options = _parser.parse(args);
 
   /// Returns the parsed configuration.
   Configuration parse() {
-    var patterns = _options['name']
-        .map((value) => _wrapFormatException('name', () => new RegExp(value)))
+    var patterns = (_options['name'] as List<String>)
+        .map/*<Pattern>*/(
+            (value) => _wrapFormatException('name', () => new RegExp(value)))
         .toList()
-        ..addAll(_options['plain-name']);
+        ..addAll(_options['plain-name'] as List<String>);
 
     var includeTagSet = new Set.from(_options['tags'] ?? [])
       ..addAll(_options['tag'] ?? []);
 
     var includeTags = includeTagSet.fold(BooleanSelector.all, (selector, tag) {
       var tagSelector = new BooleanSelector.parse(tag);
       return selector.intersection(tagSelector);
     });
 
     var excludeTagSet = new Set.from(_options['exclude-tags'] ?? [])
@@ skipping 26 matching lines @@
         pauseAfterLoad: _ifParsed('pause-after-load'),
         color: _ifParsed('color'),
         packageRoot: _ifParsed('package-root'),
         reporter: _ifParsed('reporter'),
         pubServePort: _parseOption('pub-serve', int.parse),
         concurrency: _parseOption('concurrency', int.parse),
         shardIndex: shardIndex,
         totalShards: totalShards,
         timeout: _parseOption('timeout', (value) => new Timeout.parse(value)),
         patterns: patterns,
-        platforms: _ifParsed('platform')?.map(TestPlatform.find),
-        chosenPresets: _ifParsed('preset'),
+        platforms: (_ifParsed('platform') as List<String>)
+            ?.map(TestPlatform.find),
+        chosenPresets: _ifParsed('preset') as List<String>,
         paths: _options.rest.isEmpty ? null : _options.rest,
         includeTags: includeTags,
         excludeTags: excludeTags);
   }
 
   /// Returns the parsed option for [name], or `null` if none was parsed.
   ///
   /// If the user hasn't explicitly chosen a value, we want to pass null values
   /// to [new Configuration] so that it considers those fields unset when
   /// merging with configuration from the config file.
   _ifParsed(String name) => _options.wasParsed(name) ? _options[name] : null;
 
   /// Runs [parse] on the value of the option [name], and wraps any
   /// [FormatException] it throws with additional information.
-  _parseOption(String name, parse(value)) {
+  /*=T*/ _parseOption/*<T>*/(String name, /*=T*/ parse(String value)) {
     if (!_options.wasParsed(name)) return null;
 
     var value = _options[name];
     if (value == null) return null;
 
-    return _wrapFormatException(name, () => parse(value));
+    return _wrapFormatException(name, () => parse(value as String));
   }
 
   /// Runs [parse], and wraps any [FormatException] it throws with additional
   /// information.
-  _wrapFormatException(String name, parse()) {
+  /*=T*/ _wrapFormatException/*<T>*/(String name, /*=T*/ parse()) {
     try {
       return parse();
     } on FormatException catch (error) {
       throw new FormatException('Couldn\'t parse --$name "${_options[name]}": '
           '${error.message}');
     }
   }
 }