Add a validator that tests the size of pub packages.

utils/pub/validator/size.dart

Index: utils/pub/validator/size.dart
diff --git a/utils/pub/validator/size.dart b/utils/pub/validator/size.dart
new file mode 100644
index 0000000000000000000000000000000000000000..ebe513030ede49862b852cc8c58467dcbf01d326
--- /dev/null
+++ b/utils/pub/validator/size.dart
@@ -0,0 +1,32 @@
+// 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.
+
+library size_validator;
+
+import 'dart:async';
+import 'dart:math' as math;
+
+import '../entrypoint.dart';
+import '../validator.dart';
+
+/// The maximum size of the package to upload (10 MB).
+final _MAX_SIZE = 10 * math.pow(2, 20);

[Bob Nystrom, 2013/02/01 01:29:44]

This should either be _maxSize (since it's not const) or:

const _MAX_SIZE = 10 * 1024 * 1024;

[nweiz, 2013/02/01 02:08:00]

Done.

+
+/// A validator that validates that a package isn't too big.
+class SizeValidator extends Validator {
+  final Future<int> packageSize;
+
+  SizeValidator(Entrypoint entrypoint, this.packageSize)
+    : super(entrypoint);
+
+  Future validate() {
+    return packageSize.then((size) {
+      if (size <= _MAX_SIZE) return;
+      var sizeInMb = (size / math.pow(2, 20)).toStringAsPrecision(4);
+      errors.add("Your package is $sizeInMb MB. Hosted packages may be at most "
+          "10 MB large.");

[Bob Nystrom, 2013/02/01 01:29:44]

How about "Hosted packages must be smaller than 10 MB."

(I realize that's not strictly accurate if the package happens to be exactly
10MB, but it reads nicely.)

[nweiz, 2013/02/01 02:08:00]

Done.

+    });
+  }
+}
+