Fixed bug where including relative paths would fail to find the correct file

src/xml_parsing.cpp

@@ -187,8 +187,16 @@ void XMLParser::Pimpl::loadDocImpl(BT_TinyXML2::XMLDocument* doc, bool add_inclu
 
         opened_documents.emplace_back(new BT_TinyXML2::XMLDocument());
         BT_TinyXML2::XMLDocument* next_doc = opened_documents.back().get();
+
+        // change current path to the included file for handling additional relative paths
+        const filesystem::path previous_path = current_path;
+        current_path = file_path.parent_path().make_absolute();
+
         next_doc->LoadFile(file_path.str().c_str());
         loadDocImpl(next_doc, add_includes);
+
+        // reset current path to the previous value
+        current_path = previous_path;
     }
 
     for (auto bt_node = xml_root->FirstChildElement("BehaviorTree");

tests/CMakeLists.txt

@@ -58,6 +58,11 @@ elseif(BUILD_UNIT_TESTS)
                                                 bt_sample_nodes gtest gtest_main)
     target_include_directories(${BEHAVIOR_TREE_LIBRARY}_test PRIVATE gtest/include ${GTEST_INCLUDE_DIRS})
 
+    add_custom_command(TARGET ${BEHAVIOR_TREE_LIBRARY}_test POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy_directory
+            ${CMAKE_SOURCE_DIR}/tests/trees
+            ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/trees)
+
     add_test(BehaviorTreeCoreTest ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${BEHAVIOR_TREE_LIBRARY}_test)
 
 endif()

tests/gtest_factory.cpp

@@ -2,6 +2,7 @@
 #include "action_test_node.h"
 #include "condition_test_node.h"
 #include "behaviortree_cpp_v3/xml_parsing.h"
+#include "environment.h"
 #include "../sample_nodes/crossdoor_nodes.h"
 #include "../sample_nodes/dummy_nodes.h"
 
@@ -303,4 +304,58 @@ TEST(BehaviorTreeFactory, SubTreeWithRemapping)
     ASSERT_FALSE( talk_bb->getAny("talk_out") );
 }
 
+#if !defined(USING_ROS) && !defined(USING_ROS2)
+TEST(BehaviorTreeFactory, CreateTreeFromFile)
+{
+    BehaviorTreeFactory factory;
+
+    // should not throw
+    Tree tree = factory.createTreeFromFile((environment->executable_path.parent_path() / "trees/parent_no_include.xml").str());
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickRoot());
+}
+
+TEST(BehaviorTreeFactory, CreateTreeFromFileWhichIncludesFileFromSameDirectory)
+{
+    BehaviorTreeFactory factory;
+
+    // should not throw
+    Tree tree = factory.createTreeFromFile((environment->executable_path.parent_path() / "trees/child/child_include_sibling.xml").str());
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickRoot());
+}
+
+TEST(BehaviorTreeFactory, CreateTreeFromFileWhichIncludesFileFromChildDirectory)
+{
+    BehaviorTreeFactory factory;
+
+    // should not throw
+    Tree tree = factory.createTreeFromFile((environment->executable_path.parent_path() / "trees/parent_include_child.xml").str());
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickRoot());
+}
 
+TEST(BehaviorTreeFactory, CreateTreeFromFileWhichIncludesFileFromChildDirectoryWhichIncludesFileFromSameDirectory)
+{
+    BehaviorTreeFactory factory;
+
+    // should not throw
+    Tree tree = factory.createTreeFromFile((environment->executable_path.parent_path() / "trees/parent_include_child_include_sibling.xml").str());
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickRoot());
+}
+
+TEST(BehaviorTreeFactory, CreateTreeFromFileWhichIncludesFileFromChildDirectoryWhichIncludesFileFromChildDirectory)
+{
+    BehaviorTreeFactory factory;
+
+    // should not throw
+    Tree tree = factory.createTreeFromFile((environment->executable_path.parent_path() / "trees/parent_include_child_include_child.xml").str());
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickRoot());
+}
+
+TEST(BehaviorTreeFactory, CreateTreeFromFileWhichIncludesFileFromChildDirectoryWhichIncludesFileFromParentDirectory)
+{
+    BehaviorTreeFactory factory;
+
+    // should not throw
+    Tree tree = factory.createTreeFromFile((environment->executable_path.parent_path() / "trees/parent_include_child_include_parent.xml").str());
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickRoot());
+}
+#endif

tests/gtest_tree.cpp

@@ -14,6 +14,7 @@
 #include "action_test_node.h"
 #include "condition_test_node.h"
 #include "behaviortree_cpp_v3/behavior_tree.h"
+#include "environment.h"
 
 #include <sstream>
 #include <string>
@@ -118,8 +119,16 @@ TEST_F(BehaviorTreeTest, PrintWithStream)
     ASSERT_TRUE(std::getline(stream, line, '\n').fail());
 }
 
+// define extern variable from environment.h
+Environment* environment;
+
 int main(int argc, char** argv)
 {
     testing::InitGoogleTest(&argc, argv);
+
+    // gtest will take ownership of this pointer and free it for us
+    environment = new Environment(argc, argv);
+    testing::AddGlobalTestEnvironment(environment);
+
     return RUN_ALL_TESTS();
 }

tests/include/environment.h

@@ -0,0 +1,26 @@
+#ifndef ENVIRONMENT_H
+#define ENVIRONMENT_H
+
+#include <gtest/gtest.h>
+
+#include "filesystem/path.h"
+
+class Environment : public testing::Environment
+{
+    public:
+        Environment(int argc, char** argv)
+        {
+            if (argc >= 1)
+            {
+                executable_path = filesystem::path(argv[0]).make_absolute();
+            }
+        }
+
+        // the absolute path to the test executable
+        filesystem::path executable_path;
+};
+
+// for accessing the environment within a test
+extern Environment* environment;
+
+#endif

tests/trees/child/child/child_child_no_include.xml

@@ -0,0 +1,5 @@
+<root main_tree_to_execute = "ChildChildNoInclude">
+  <BehaviorTree ID="ChildChildNoInclude">
+    <AlwaysSuccess />
+  </BehaviorTree>
+</root>

tests/trees/child/child_include_child.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ChildIncludeChild">
+  <include path="child/child_child_no_include.xml" />
+
+  <BehaviorTree ID="ChildIncludeChild">
+    <Sequence>
+      <SubTree ID="ChildChildNoInclude" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/child/child_include_parent.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ChildIncludeParent">
+  <include path="../parent_no_include.xml" />
+
+  <BehaviorTree ID="ChildIncludeParent">
+    <Sequence>
+      <SubTree ID="ParentNoInclude" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/child/child_include_sibling.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ChildIncludeSibling">
+  <include path="child_no_include.xml" />
+
+  <BehaviorTree ID="ChildIncludeSibling">
+    <Sequence>
+      <SubTree ID="ChildNoInclude" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/child/child_no_include.xml

@@ -0,0 +1,5 @@
+<root main_tree_to_execute = "ChildNoInclude">
+  <BehaviorTree ID="ChildNoInclude">
+    <AlwaysSuccess />
+  </BehaviorTree>
+</root>

tests/trees/parent_include_child.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ParentIncludeChild">
+  <include path="child/child_no_include.xml" />
+
+  <BehaviorTree ID="ParentIncludeChild">
+    <Sequence>
+      <SubTree ID="ChildNoInclude" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/parent_include_child_include_child.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ParentIncludeChildIncludeChild">
+  <include path="child/child_include_child.xml" />
+
+  <BehaviorTree ID="ParentIncludeChildIncludeChild">
+    <Sequence>
+      <SubTree ID="ChildIncludeChild" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/parent_include_child_include_parent.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ParentIncludeChildIncludeParent">
+  <include path="child/child_include_parent.xml" />
+
+  <BehaviorTree ID="ParentIncludeChildIncludeParent">
+    <Sequence>
+      <SubTree ID="ChildIncludeParent" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/parent_include_child_include_sibling.xml

@@ -0,0 +1,10 @@
+<root main_tree_to_execute = "ParentIncludeChildIncludeSibling">
+  <include path="child/child_include_sibling.xml" />
+
+  <BehaviorTree ID="ParentIncludeChildIncludeSibling">
+    <Sequence>
+      <SubTree ID="ChildIncludeSibling" />
+      <AlwaysSuccess />
+    </Sequence>
+  </BehaviorTree>
+</root>

tests/trees/parent_no_include.xml

@@ -0,0 +1,5 @@
+<root main_tree_to_execute = "ParentNoInclude">
+  <BehaviorTree ID="ParentNoInclude">
+    <AlwaysSuccess />
+  </BehaviorTree>
+</root>