pkg/args Option should be more strict about names and abbreviations

pkg/args/lib/args.dart

Index: pkg/args/lib/args.dart
diff --git a/pkg/args/lib/args.dart b/pkg/args/lib/args.dart
index 304827b41ed4650f7d1b506c7f9a5240ac7d7ac0..48cef1642ece730acba2bbc42027c05a910255b0 100644
--- a/pkg/args/lib/args.dart
+++ b/pkg/args/lib/args.dart
@@ -285,11 +285,6 @@ class ArgParser {
 
     // Make sure the abbreviation isn't too long or in use.
     if (abbr != null) {
-      if (abbr.length > 1) {
-        throw new ArgumentError(
-            'Abbreviation "$abbr" is longer than one character.');
-      }
-
       var existing = findByAbbreviation(abbr);
       if (existing != null) {
         throw new ArgumentError(
@@ -342,7 +337,7 @@ class ArgParser {
 class Option {
   final String name;
   final String abbreviation;
-  final List allowed;
+  final List<String> allowed;
   final defaultValue;
   final Function callback;
   final String help;
@@ -353,7 +348,33 @@ class Option {
 
   Option(this.name, this.abbreviation, this.help, this.allowed,
       this.allowedHelp, this.defaultValue, this.callback, {this.isFlag,
-      this.negatable, this.allowMultiple: false});
+      this.negatable, this.allowMultiple: false}) {
+
+    if (name.isEmpty) {
+      throw new ArgumentError('Name cannot be empty.');
+    } else if (name.startsWith('-')) {
+      throw new ArgumentError('Name $name cannot start with "-".');
+    }
+
+    // Ensure name does not contain any invalid characters.
+    if (_invalidChars.hasMatch(name)) {
+      throw new ArgumentError('Name "$name" contains invalid characters.');
+    }
+
+    if (abbreviation != null) {
+      if (abbreviation.length != 1) {
+        throw new ArgumentError('Abbreviation must be null or have length 1.');
+      } else if(abbreviation == '-') {
+        throw new ArgumentError('Abbreviation cannot be "-".');
+      }
+
+      if (_invalidChars.hasMatch(abbreviation)) {
+        throw new ArgumentError('Abbreviation is an invalid character.');
+      }
+    }
+  }
+
+  static final _invalidChars = new RegExp(r'''[ \t\r\n"'\\/]''');
 }
 
 /**