Make pub strong-mode clean.

lib/src/barback/transformer_config.dart

 // Copyright (c) 2013, 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 'package:glob/glob.dart';
 import 'package:path/path.dart' as p;
 import 'package:source_span/source_span.dart';
 import 'package:yaml/yaml.dart';
 
 import 'transformer_id.dart';
@@ skipping 61 matching lines @@
 
   /// Parses [identifier] as a [TransformerId] with [configuration].
   ///
   /// [identifierSpan] is the source span for [identifier].
   factory TransformerConfig.parse(String identifier, SourceSpan identifierSpan,
         YamlMap configuration) =>
       new TransformerConfig(new TransformerId.parse(identifier, identifierSpan),
           configuration);
 
   factory TransformerConfig(TransformerId id, YamlMap configurationNode) {
-    parseField(key) {
+    Set<Glob> parseField(String key) {
       if (!configurationNode.containsKey(key)) return null;
       var fieldNode = configurationNode.nodes[key];
       var field = fieldNode.value;
 
       if (field is String) {
         return new Set.from([new Glob(field, context: p.url, recursive: true)]);
       }
 
       if (field is! List) {
         throw new SourceSpanFormatException(
             '"$key" field must be a string or list.', fieldNode.span);
       }
 
       return new Set.from(field.nodes.map((node) {
         if (node.value is String) {
           return new Glob(node.value, context: p.url, recursive: true);
         }
 
         throw new SourceSpanFormatException(
             '"$key" field may contain only strings.', node.span);
       }));
     }
 
-    var includes = null;
-    var excludes = null;
-
-    var configuration;
-    var span;
+    Set<Glob> includes;
+    Set<Glob> excludes;
+    Map configuration;
+    SourceSpan span;
     if (configurationNode == null) {
       configuration = {};
       span = id.span;
     } else {
       // Don't write to the immutable YAML map.
       configuration = new Map.from(configurationNode);
       span = configurationNode.span;
 
       // Pull out the exclusions/inclusions.
       includes = parseField("\$include");
@@ skipping 28 matching lines @@
       for (var exclude in excludes) {
         if (exclude.matches(pathWithinPackage)) return false;
       }
     }
 
     // If there are any includes, it must match one of them.
     return includes == null ||
         includes.any((include) => include.matches(pathWithinPackage));
   }
 }