[mojo] Update mojo .tmpl file to support nesting enums.

Before this change, if the min_version was set on a nested enum
then it would not compile. This change updates that if statement
and adds a new test case to validate the scenario.


Test: Run mojo_unittest.exe
Bug: 896777
Change-Id: I68fe3878d89d114b5601a00770d9653dc764ebd0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2119660
Commit-Queue: Emily Andrews <emiled@microsoft.com>
Reviewed-by: Ken Rockot <rockot@google.com>
Cr-Commit-Position: refs/heads/master@{#754155}

mojo/public/cpp/bindings/tests/struct_unittest.cc

@@ -525,5 +525,22 @@ TEST_F(StructTest, VersionedStructConstructor) {
   EXPECT_EQ(1, reordered->c);
 }
 
+TEST_F(StructTest, EnumNestedStructTest) {
+  EnumNestedStructPtr enum_nested_struct =
+      EnumNestedStruct::New(EnumNestedStruct::StructEnum::FIRST);
+  EXPECT_EQ(EnumNestedStruct::StructEnum::FIRST,
+            enum_nested_struct->local_enum_state_);
+
+  enum_nested_struct->local_enum_state_ = EnumNestedStruct::StructEnum::SECOND;
+
+  EnumNestedStructPtr expected_output(
+      EnumNestedStruct::New(EnumNestedStruct::StructEnum::SECOND));
+
+  EnumNestedStructPtr output = SerializeAndDeserialize<EnumNestedStructPtr>(
+      std::move(enum_nested_struct));
+  EXPECT_TRUE(output.Equals(expected_output));
+  EXPECT_EQ(EnumNestedStruct::StructEnum::SECOND, output->local_enum_state_);
+}
+
 }  // namespace test
 }  // namespace mojo

mojo/public/interfaces/bindings/tests/test_structs.mojom

@@ -414,3 +414,12 @@ struct ContainsHashable {
 struct SimpleNestedStruct {
   ContainsOther nested;
 };
+
+struct EnumNestedStruct {
+  enum StructEnum {
+    FIRST,
+    SECOND
+  };
+
+  [MinVersion=1] StructEnum local_enum_state_;
+};

mojo/public/tools/bindings/generators/cpp_templates/struct_data_view_declaration.tmpl

@@ -64,7 +64,7 @@ class {{struct.name}}DataView {
   {{kind|cpp_data_view_type}} {{name}}() const {
 {%-     if pf.min_version != 0 %}
     if (data_->header_.version < {{pf.min_version}})
-      return {{kind|get_qualified_name_for_kind}}{};
+      return {{kind|cpp_data_view_type}}{};
 {%-     endif %}
     return static_cast<{{kind|cpp_data_view_type}}>(data_->{{name}});
   }