Move pub into sdk/lib/_internal.

utils/pub/validator/lib.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 lib_validator;
-
-import 'dart:async';
-import 'dart:io';
-
-import 'package:pathos/path.dart' as path;
-
-import '../entrypoint.dart';
-import '../io.dart';
-import '../system_cache.dart';
-import '../utils.dart';
-import '../validator.dart';
-
-// TODO(nweiz): When issue 7196 is fixed, complain about non-Dart files in lib.
-/// A validator that checks that libraries in "lib/" (and not "lib/src/") exist
-/// and are well-formed.
-class LibValidator extends Validator {
-  LibValidator(Entrypoint entrypoint)
-    : super(entrypoint);
-
-  Future validate() {
-    return new Future.sync(() {
-      var libDir = path.join(entrypoint.root.dir, "lib");
-
-      if (!dirExists(libDir)) {
-        errors.add('You must have a "lib" directory.\n'
-            "Without that, users cannot import any code from your package.");
-        return;
-      }
-
-      var files = listDir(libDir)
-          .map((file) => path.relative(file, from: libDir))
-          .toList();
-      if (files.isEmpty) {
-        errors.add('You must have a non-empty "lib" directory.\n'
-            "Without that, users cannot import any code from your package.");
-      } else if (files.length == 1 && files.first == "src") {
-        errors.add('The "lib" directory must contain something other than '
-            '"src".\n'
-            "Otherwise, users cannot import any code from your package.");
-      }
-    });
-  }
-}