First stab at "pub run" command.

sdk/lib/_internal/pub/test/run/app_can_read_from_stdin_test.dart

Index: sdk/lib/_internal/pub/test/run/app_can_read_from_stdin_test.dart
diff --git a/sdk/lib/_internal/pub/test/run/app_can_read_from_stdin_test.dart b/sdk/lib/_internal/pub/test/run/app_can_read_from_stdin_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6786989594d6c8f4f187cfc8d74e8a815888808f
--- /dev/null
+++ b/sdk/lib/_internal/pub/test/run/app_can_read_from_stdin_test.dart
@@ -0,0 +1,36 @@
+// Copyright (c) 2014, 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.
+
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+
+const SCRIPT = """
+import 'dart:io';
+
+main() {
+  var line1 = stdin.readLineSync();
+  print("between");
+  var line2 = stdin.readLineSync();
+  print(line1);
+  print(line2);
+}
+""";
+
+main() {
+  initConfig();
+  integration('the spawned application can read from stdin', () {
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir("bin", [
+        d.file("script.dart", SCRIPT)
+      ])
+    ]).create();
+
+    var pub = startPub(args: ["run", "script"]);
+    pub.writeLine("first");
+    pub.stdout.expect("between");
+    pub.writeLine("second");

[nweiz, 2014/05/29 19:30:09]

Why aren't you expecting the script to print "first" and "second" here as well?

[Bob Nystrom, 2014/05/30 18:17:47]

<sigh> Still getting the last bit of seawater out of my brain.

Done.

+    pub.shouldExit(0);
+  });
+}