Add mju_getXMLDependencies that given an MJCF file returns filepaths to all of it's dependencies.

PiperOrigin-RevId: 814203235
Change-Id: Ib5c2e2f4dd42224a768c88d76473544190c72bc0

test/xml/xml_utils_test.cc

@@ -0,0 +1,46 @@
+// Copyright 2025 DeepMind Technologies Limited
+//
+// 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 <set>
+#include <string>
+#include <vector>
+
+#include <gtest/gtest.h>
+#include <mujoco/mujoco.h>
+#include "test/fixture.h"
+
+namespace mujoco {
+namespace {
+
+TEST_F(MujocoTest, GetXMLDependenciesTest) {
+  static const std::vector<std::string> kModelPaths = {
+      GetTestDataFilePath("xml/testdata/many_dependencies.xml"),
+      GetTestDataFilePath("xml/testdata/parent_model.xml"),
+      GetTestDataFilePath("xml/testdata/child.xml"),
+      GetTestDataFilePath("xml/testdata/meshes/mesh1.obj"),
+      GetTestDataFilePath("xml/testdata/meshes/flex.obj"),
+      GetTestDataFilePath("xml/testdata/meshes/cube.skn"),
+  };
+
+  mjStringVec dependencies;
+  mju_getXMLDependencies(kModelPaths[0].c_str(), &dependencies);
+  std::set<std::string> dependency_set{dependencies.begin(),
+                                       dependencies.end()};
+  std::set<std::string> expected_dependency_set{kModelPaths.begin(),
+                                                kModelPaths.end()};
+  EXPECT_EQ(dependency_set, expected_dependency_set);
+}
+}  // namespace
+}  // namespace mujoco