Add a validator that checks package names.

utils/pub/validator/name.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 name_validator;
+
+import 'dart:io';
+
+import '../entrypoint.dart';
+import '../io.dart';
+import '../validator.dart';
+
+/// Dart reserved words, from the Dart spec.
+final _RESERVED_WORDS = [
+  "abstract", "as", "dynamic", "export", "external", "factory", "get",
+  "implements", "import", "library", "operator", "part", "set", "static",
+  "typedef"
+];
+
+/// A validator that validates the name of the package and its libraries.
+class NameValidator extends Validator {
+  NameValidator(Entrypoint entrypoint)
+    : super(entrypoint);
+
+  Future validate() {
+    _checkName(entrypoint.root.name, 'Package name "${entrypoint.root.name}"');
+
+    var libDir = join(entrypoint.root.dir, "lib");
+    return dirExists(libDir).chain((libDirExists) {
+      if (!libDirExists) return new Future.immediate([]);
+      return listDir(libDir, recursive: true);
+    }).transform((files) {
+      for (var file in files) {
+        if (file.contains("/src/")) continue;
+        if (new Path(file).extension != 'dart') continue;
+        var libName = new Path(file).filenameWithoutExtension;
+        _checkName(libName, 'The name of "$file", "$libName",');
+      }
+    });
+  }
+
+  void _checkName(String name, String description) {
+    if (name == "") {
+      errors.add("$description may not be empty.");
+    } else if (!new RegExp(r"^[a-zA-Z0-9_]*$").hasMatch(name)) {
+      errors.add("$description must be a valid Dart identifier: it may only "
+          "contain letters, numbers, and underscores.");
+    } else if (!new RegExp(r"^[a-zA-Z]").hasMatch(name)) {
+      errors.add("$description must be a valid Dart identifier: it must begin "
+          "with a letter.");
+    } else if (_RESERVED_WORDS.contains(name.toLowerCase())) {
+      errors.add("$description must be a valid Dart identifier: it may not be "
+          "a reserved word in Dart.");
+    } else if (new RegExp(r"[A-Z]").hasMatch(name)) {
+      warnings.add('$description should be lower-case. Maybe use '
+          '"${_unCamelCase(name)}"?');
+    }
+  }
+
+  String _unCamelCase(String source) {
+    var builder = new StringBuffer();
+    var lastMatchEnd = 0;
+    for (var match in new RegExp(r"[a-z]([A-Z])").allMatches(source)) {
+      builder
+        ..add(source.substring(lastMatchEnd, match.start + 1))
+        ..add("_")
+        ..add(match.group(1).toLowerCase());
+      lastMatchEnd = match.end;
+    }
+    builder.add(source.substring(lastMatchEnd));
+    return builder.toString().toLowerCase();
+  }
+}