[xml] Add unit tests for TXMLEngine and TXMLFile

io/xml/CMakeLists.txt

@@ -24,3 +24,6 @@ ROOT_STANDARD_LIBRARY_PACKAGE(XMLIO
                                  src/TXMLPlayer.cxx
                                  src/TXMLSetup.cxx
                               DEPENDENCIES RIO)
+
+
+ROOT_ADD_TEST_SUBDIRECTORY(test)

io/xml/test/CMakeLists.txt

@@ -0,0 +1 @@
+ROOT_ADD_GTEST(test_xmlfile test_xmlfile.cxx LIBRARIES XMLIO Core RIO Hist)

io/xml/test/test_xmlfile.cxx

@@ -0,0 +1,203 @@
+#include <gtest/gtest.h>
+#include "TXMLFile.h"
+#include "TXMLEngine.h"
+#include "TH1I.h"
+#include "TObjString.h"
+#include "TList.h"
+#include "TNamed.h"
+#include "ROOT/TestSupport.hxx"
+
+#include <memory>
+#include <string>
+
+// =============================================================================
+// TXMLEngine Tests: DOM construction, attributes, parsing and serialization
+// =============================================================================
+
+TEST(TXMLEngineTest, ConstructAndParseString)
+{
+   TXMLEngine xml;
+
+   // Build a DOM tree
+   XMLNodePointer_t mainNode = xml.NewChild(nullptr, nullptr, "config");
+   xml.NewAttr(mainNode, nullptr, "version", "1.0");
+
+   XMLNodePointer_t child1 = xml.NewChild(mainNode, nullptr, "server", "localhost");
+   xml.NewIntAttr(child1, "port", 8080);
+
+   XMLNodePointer_t child2 = xml.NewChild(mainNode, nullptr, "timeout", "30");
+
+   XMLDocPointer_t doc = xml.NewDoc();
+   xml.DocSetRootElement(doc, mainNode);
+
+   TString xmlStr;
+   xml.SaveSingleNode(mainNode, &xmlStr);
+   xml.FreeDoc(doc);
+
+   EXPECT_FALSE(xmlStr.IsNull());
+
+   // Parse back from string
+   XMLDocPointer_t parsedDoc = xml.ParseString(xmlStr.Data());
+   ASSERT_NE(parsedDoc, nullptr);
+
+   XMLNodePointer_t root = xml.DocGetRootElement(parsedDoc);
+   ASSERT_NE(root, nullptr);
+   EXPECT_STREQ(xml.GetNodeName(root), "config");
+   EXPECT_TRUE(xml.HasAttr(root, "version"));
+   EXPECT_STREQ(xml.GetAttr(root, "version"), "1.0");
+
+   XMLNodePointer_t n1 = xml.GetChild(root);
+   ASSERT_NE(n1, nullptr);
+   EXPECT_STREQ(xml.GetNodeName(n1), "server");
+   EXPECT_STREQ(xml.GetNodeContent(n1), "localhost");
+   EXPECT_EQ(xml.GetIntAttr(n1, "port"), 8080);
+
+   XMLNodePointer_t n2 = xml.GetNext(n1);
+   ASSERT_NE(n2, nullptr);
+   EXPECT_STREQ(xml.GetNodeName(n2), "timeout");
+   EXPECT_STREQ(xml.GetNodeContent(n2), "30");
+
+   EXPECT_EQ(xml.GetNext(n2), nullptr);
+
+   xml.FreeDoc(parsedDoc);
+}
+
+TEST(TXMLEngineTest, FileSaveAndParse)
+{
+   ROOT::TestSupport::FileRaii xmlFile{"test_engine_doc.xml"};
+
+   {
+      TXMLEngine xml;
+      XMLNodePointer_t root = xml.NewChild(nullptr, nullptr, "dataset");
+      xml.NewAttr(root, nullptr, "name", "Run2026");
+
+      XMLNodePointer_t item = xml.NewChild(root, nullptr, "events", "10000");
+      xml.NewAttr(item, nullptr, "type", "MC");
+
+      XMLDocPointer_t doc = xml.NewDoc();
+      xml.DocSetRootElement(doc, root);
+      xml.SaveDoc(doc, xmlFile.GetPath().c_str());
+      xml.FreeDoc(doc);
+   }
+
+   {
+      TXMLEngine xml;
+      XMLDocPointer_t doc = xml.ParseFile(xmlFile.GetPath().c_str());
+      ASSERT_NE(doc, nullptr);
+
+      XMLNodePointer_t root = xml.DocGetRootElement(doc);
+      ASSERT_NE(root, nullptr);
+      EXPECT_STREQ(xml.GetNodeName(root), "dataset");
+      EXPECT_STREQ(xml.GetAttr(root, "name"), "Run2026");
+
+      XMLNodePointer_t item = xml.GetChild(root);
+      ASSERT_NE(item, nullptr);
+      EXPECT_STREQ(xml.GetNodeName(item), "events");
+      EXPECT_STREQ(xml.GetNodeContent(item), "10000");
+      EXPECT_STREQ(xml.GetAttr(item, "type"), "MC");
+
+      xml.FreeDoc(doc);
+   }
+}
+
+// =============================================================================
+// TXMLFile Tests: Object serialization, directories, keys, and retrieval
+// =============================================================================
+
+TEST(TXMLFileTest, WriteAndReadObjects)
+{
+   ROOT::TestSupport::FileRaii xmlFile{"test_xmlfile_objects.xml"};
+
+   {
+      TXMLFile f(xmlFile.GetPath().c_str(), "RECREATE");
+      ASSERT_TRUE(f.IsOpen());
+      ASSERT_FALSE(f.IsZombie());
+
+      auto h1 = std::make_unique<TH1I>("h1", "Test Histogram", 10, 0, 10);
+      h1->Fill(2);
+      h1->Fill(5);
+      h1->Fill(5);
+      h1->Write("myhist");
+
+      auto str = std::make_unique<TObjString>("Hello XML World");
+      str->Write("mystr");
+
+      auto named = std::make_unique<TNamed>("entryKey", "entryValue");
+      named->Write("myentry");
+
+      f.Close();
+   }
+
+   {
+      TXMLFile f(xmlFile.GetPath().c_str(), "READ");
+      ASSERT_TRUE(f.IsOpen());
+      ASSERT_FALSE(f.IsZombie());
+
+      std::unique_ptr<TH1I> h1(dynamic_cast<TH1I *>(f.Get("myhist")));
+      ASSERT_NE(h1, nullptr);
+      EXPECT_EQ(h1->GetEntries(), 3);
+      EXPECT_EQ(h1->GetBinContent(h1->FindBin(2)), 1);
+      EXPECT_EQ(h1->GetBinContent(h1->FindBin(5)), 2);
+      EXPECT_STREQ(h1->GetTitle(), "Test Histogram");
+
+      std::unique_ptr<TObjString> str(dynamic_cast<TObjString *>(f.Get("mystr")));
+      ASSERT_NE(str, nullptr);
+      EXPECT_STREQ(str->GetString().Data(), "Hello XML World");
+
+      std::unique_ptr<TNamed> named(dynamic_cast<TNamed *>(f.Get("myentry")));
+      ASSERT_NE(named, nullptr);
+      EXPECT_STREQ(named->GetName(), "entryKey");
+      EXPECT_STREQ(named->GetTitle(), "entryValue");
+
+      f.Close();
+   }
+}
+
+TEST(TXMLFileTest, SubdirectoriesAndKeyListing)
+{
+   ROOT::TestSupport::FileRaii xmlFile{"test_xmlfile_subdir.xml"};
+
+   {
+      TXMLFile f(xmlFile.GetPath().c_str(), "RECREATE");
+      ASSERT_TRUE(f.IsOpen());
+
+      TDirectory *subDir = f.mkdir("subfolder");
+      ASSERT_NE(subDir, nullptr);
+      subDir->cd();
+
+      auto subStr = std::make_unique<TObjString>("Nested Content");
+      subStr->Write("nestedStr");
+
+      f.cd();
+      auto rootStr = std::make_unique<TObjString>("Root Content");
+      rootStr->Write("topStr");
+
+      f.Close();
+   }
+
+   {
+      TXMLFile f(xmlFile.GetPath().c_str(), "READ");
+      ASSERT_TRUE(f.IsOpen());
+
+      // Check root directory keys
+      TList *keys = f.GetListOfKeys();
+      ASSERT_NE(keys, nullptr);
+      EXPECT_NE(keys->FindObject("subfolder"), nullptr);
+      EXPECT_NE(keys->FindObject("topStr"), nullptr);
+
+      std::unique_ptr<TObjString> topStr(dynamic_cast<TObjString *>(f.Get("topStr")));
+      ASSERT_NE(topStr, nullptr);
+      EXPECT_STREQ(topStr->GetString().Data(), "Root Content");
+
+      // Check subdirectory keys and content
+      TDirectory *subDir = nullptr;
+      f.GetObject("subfolder", subDir);
+      ASSERT_NE(subDir, nullptr);
+
+      std::unique_ptr<TObjString> nestedStr(dynamic_cast<TObjString *>(subDir->Get("nestedStr")));
+      ASSERT_NE(nestedStr, nullptr);
+      EXPECT_STREQ(nestedStr->GetString().Data(), "Nested Content");
+
+      f.Close();
+   }
+}