Revert "Revert "Use native async/await support in pub.""

sdk/lib/_internal/pub_generated/lib/src/validator/pubspec_field.dart

Index: sdk/lib/_internal/pub_generated/lib/src/validator/pubspec_field.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/validator/pubspec_field.dart b/sdk/lib/_internal/pub_generated/lib/src/validator/pubspec_field.dart
deleted file mode 100644
index d0f55b70cd3f57c6cada926336b878d6a4155ab3..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/validator/pubspec_field.dart
+++ /dev/null
@@ -1,111 +0,0 @@
-// 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 pub.validator.pubspec_field;
-
-import 'dart:async';
-
-import '../entrypoint.dart';
-import '../validator.dart';
-
-/// A validator that checks that the pubspec has valid "author" and "homepage"
-/// fields.
-class PubspecFieldValidator extends Validator {
-  PubspecFieldValidator(Entrypoint entrypoint)
-      : super(entrypoint);
-
-  Future validate() {
-    _validateAuthors();
-    _validateFieldIsString('description');
-    _validateFieldIsString('homepage');
-    _validateFieldUrl('homepage');
-    _validateFieldUrl('documentation');
-
-    // Any complex parsing errors in version will be exposed through
-    // [Pubspec.allErrors].
-    _validateFieldIsString('version');
-
-    // Pubspec errors are detected lazily, so we make sure there aren't any
-    // here.
-    for (var error in entrypoint.root.pubspec.allErrors) {
-      errors.add('In your pubspec.yaml, ${error.message}');
-    }
-
-    return new Future.value();
-  }
-
-  /// Adds an error if the "author" or "authors" field doesn't exist or has the
-  /// wrong type.
-  void _validateAuthors() {
-    var pubspec = entrypoint.root.pubspec;
-    var author = pubspec.fields['author'];
-    var authors = pubspec.fields['authors'];
-    if (author == null && authors == null) {
-      errors.add('Your pubspec.yaml must have an "author" or "authors" field.');
-      return;
-    }
-
-    if (author != null && author is! String) {
-      errors.add(
-          'Your pubspec.yaml\'s "author" field must be a string, but it '
-              'was "$author".');
-      return;
-    }
-
-    if (authors != null &&
-        (authors is! List || authors.any((author) => author is! String))) {
-      errors.add(
-          'Your pubspec.yaml\'s "authors" field must be a list, but '
-              'it was "$authors".');
-      return;
-    }
-
-    if (authors == null) authors = [author];
-
-    var hasName = new RegExp(r"^ *[^< ]");
-    var hasEmail = new RegExp(r"<[^>]+> *$");
-    for (var authorName in authors) {
-      if (!hasName.hasMatch(authorName)) {
-        warnings.add(
-            'Author "$authorName" in pubspec.yaml should have a ' 'name.');
-      }
-      if (!hasEmail.hasMatch(authorName)) {
-        warnings.add(
-            'Author "$authorName" in pubspec.yaml should have an '
-                'email address\n(e.g. "name <email>").');
-      }
-    }
-  }
-
-  /// Adds an error if [field] doesn't exist or isn't a string.
-  void _validateFieldIsString(String field) {
-    var value = entrypoint.root.pubspec.fields[field];
-    if (value == null) {
-      errors.add('Your pubspec.yaml is missing a "$field" field.');
-    } else if (value is! String) {
-      errors.add(
-          'Your pubspec.yaml\'s "$field" field must be a string, but '
-              'it was "$value".');
-    }
-  }
-
-  /// Adds an error if the URL for [field] is invalid.
-  void _validateFieldUrl(String field) {
-    var url = entrypoint.root.pubspec.fields[field];
-    if (url == null) return;
-
-    if (url is! String) {
-      errors.add(
-          'Your pubspec.yaml\'s "$field" field must be a string, but ' 'it was "$url".');
-      return;
-    }
-
-    var goodScheme = new RegExp(r'^https?:');
-    if (!goodScheme.hasMatch(url)) {
-      errors.add(
-          'Your pubspec.yaml\'s "$field" field must be an "http:" or '
-              '"https:" URL, but it was "$url".');
-    }
-  }
-}