Create binstubs for executables when activating a package.

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

Index: sdk/lib/_internal/pub/test/pubspec_test.dart
diff --git a/sdk/lib/_internal/pub/test/pubspec_test.dart b/sdk/lib/_internal/pub/test/pubspec_test.dart
index e34ce431c0d2dca1bc1c859c4d3f1d7fe5b1fd4c..1c1cb9ff336235e2c560eb802759ec7151b7c0af 100644
--- a/sdk/lib/_internal/pub/test/pubspec_test.dart
+++ b/sdk/lib/_internal/pub/test/pubspec_test.dart
@@ -444,5 +444,45 @@ publish_to: none
             (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("uses the key if the value is null", () {
+        var pubspec = new Pubspec.parse('''
+executables:
+  command:
+''', sources);
+        expect(pubspec.executables['command'], equals('command'));
+      });
+    });
   });
 }