Add test for descriptor loading

Signed-off-by: Michael Carroll <mjcarroll@intrinsic.ai>

test/desc/testing.proto.bin

@@ -0,0 +1,16 @@
+
+C
+testing/bytes.prototesting"
+Bytes
+data
 
(Rdatabproto3
+�

+testing/message.prototesting"
+
+FooMessage
+foo
 
(	Rfoo"
+
+BarMessage
+foo
 
(	Rfoo"
+
+BazMessage
+foo
 
(	Rfoobproto3

test/desc/testing/bytes.proto

@@ -0,0 +1,8 @@
+syntax = "proto3";
+
+package testing;
+
+message Bytes
+{
+  bytes data    = 1;
+}

test/desc/testing/message.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package testing;
+
+message FooMessage {
+    string data = 1;
+}
+
+message BarMessage {
+    FooMessage foo = 1;
+}
+
+message BazMessage {
+    BarMessage bar = 1;
+}

test/integration/CMakeLists.txt

@@ -6,3 +6,8 @@ if(MSVC)
 endif()
 
 gz_build_tests(TYPE INTEGRATION SOURCES ${tests})
+
+if (TARGET INTEGRATION_descriptors)
+  target_compile_definitions(INTEGRATION_descriptors
+    PRIVATE GZ_MSGS_TEST_PATH="${PROJECT_SOURCE_DIR}/test")
+endif()

test/integration/descriptors.cc

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2024 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <gtest/gtest.h>
+
+#include <filesystem>
+
+#include "gz/msgs/Factory.hh"
+
+static constexpr const char * kMsgsTestPath = GZ_MSGS_TEST_PATH;
+
+TEST(FactoryTest, DynamicFactory)
+{
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("example.msgs.StringMsg"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.Bytes"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.FooMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BarMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BazMessage"));
+
+  // Test loading an invalid path
+  {
+    std::filesystem::path test_path(kMsgsTestPath);
+    std::string paths = (test_path / "desc" / "does_not_exist.desc").string();
+    gz::msgs::Factory::LoadDescriptors(paths);
+  }
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("example.msgs.StringMsg"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.Bytes"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.FooMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BarMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BazMessage"));
+
+  // Test loading an empty file
+  {
+    std::filesystem::path test_path(kMsgsTestPath);
+    std::string paths = (test_path / "desc" / "testing.proto").string();
+    gz::msgs::Factory::LoadDescriptors(paths);
+  }
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("example.msgs.StringMsg"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.Bytes"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.FooMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BarMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BazMessage"));
+
+  // Load a valid descriptor file with one message type
+  {
+    std::filesystem::path test_path(kMsgsTestPath);
+    std::string paths = (test_path / "desc" / "stringmsg.desc").string();
+    gz::msgs::Factory::LoadDescriptors(paths);
+  }
+
+  EXPECT_NE(nullptr, gz::msgs::Factory::New("example.msgs.StringMsg"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.Bytes"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.FooMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BarMessage"));
+  EXPECT_EQ(nullptr, gz::msgs::Factory::New("testing.BazMessage"));
+
+  // Load a directory
+  {
+    std::filesystem::path test_path(kMsgsTestPath);
+    std::string paths = (test_path / "desc").string();
+    gz::msgs::Factory::LoadDescriptors(paths);
+  }
+
+  EXPECT_NE(nullptr, gz::msgs::Factory::New("example.msgs.StringMsg"));
+  EXPECT_NE(nullptr, gz::msgs::Factory::New("testing.Bytes"));
+  EXPECT_NE(nullptr, gz::msgs::Factory::New("testing.FooMessage"));
+  EXPECT_NE(nullptr, gz::msgs::Factory::New("testing.BarMessage"));
+  EXPECT_NE(nullptr, gz::msgs::Factory::New("testing.BazMessage"));
+
+}