Create binstubs for executables when activating a package.

sdk/lib/_internal/pub_generated/test/pubspec_test.dart

 library pubspec_test;
 import 'dart:async';
 import 'package:unittest/unittest.dart';
 import '../lib/src/package.dart';
 import '../lib/src/pubspec.dart';
 import '../lib/src/source.dart';
 import '../lib/src/source_registry.dart';
 import '../lib/src/version.dart';
 import 'test_pub.dart';
 class MockSource extends Source {
@@ skipping 368 matching lines @@
 publish_to: none
 ''', sources);
         expect(pubspec.publishTo, equals("none"));
       });
       test("throws on other strings", () {
         expectPubspecException(
             'publish_to: http://bad.url:not-port',
             (pubspec) => pubspec.publishTo);
       });
     });
+    group("executables", () {
+      test("defaults to an empty map if omitted", () {
+        var pubspec = new Pubspec.parse('', sources);
+        expect(pubspec.executables, isEmpty);
+      });
+      test("throws if not a map", () {
+        expectPubspecException(
+            'executables: not map',
+            (pubspec) => pubspec.executables);
+      });
+      test("throws if key is not a string", () {
+        expectPubspecException(
+            'executables: {123: value}',
+            (pubspec) => pubspec.executables);
+      });
+      test("throws if a key isn't a simple name", () {
+        expectPubspecException(
+            'executables: {funny/name: ok}',
+            (pubspec) => pubspec.executables);
+      });
+      test("throws if a value is not a string", () {
+        expectPubspecException(
+            'executables: {command: 123}',
+            (pubspec) => pubspec.executables);
+      });
+      test("throws if a value isn't a simple name", () {
+        expectPubspecException(
+            'executables: {command: funny_name/part}',
+            (pubspec) => pubspec.executables);
+      });
+      test("allows a null value", () {
+        var pubspec = new Pubspec.parse('''
+executables:
+  command:
+''', sources);
+        expect(pubspec.executables['command'], isNull);
+      });
+    });
   });
 }