[core] Add essential unit tests for TObjArray

core/cont/test/CMakeLists.txt

@@ -11,3 +11,4 @@ ROOT_ADD_GTEST(TSeqTests TSeqTests.cxx LIBRARIES Core)
 ROOT_ADD_GTEST(testIter testIter.cxx LIBRARIES Core)
 ROOT_ADD_GTEST(TListTest TListTest.cxx LIBRARIES Core)
 ROOT_ADD_GTEST(THashListTest THashListTest.cxx LIBRARIES Core)
+ROOT_ADD_GTEST(TObjArrayTest TObjArrayTest.cxx LIBRARIES Core)

core/cont/test/TObjArrayTest.cxx

@@ -0,0 +1,317 @@
+#include "gtest/gtest.h"
+#include "TNamed.h"
+#include "TObjArray.h"
+
+namespace {
+class TrackObject : public TObject {
+public:
+   static int fgCount;
+   TrackObject() { fgCount++; }
+   ~TrackObject() override { fgCount--; }
+};
+int TrackObject::fgCount = 0;
+} // namespace
+
+TEST(TObjArrayTest, DefaultConstructor)
+{
+   TObjArray array;
+   EXPECT_EQ(array.GetEntries(), 0);
+   EXPECT_EQ(array.GetEntriesFast(), 0);
+   EXPECT_EQ(array.GetLast(), -1);
+   EXPECT_TRUE(array.IsEmpty());
+}
+
+TEST(TObjArrayTest, AddAndAt)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("first", "");
+   auto *s2 = new TNamed("second", "");
+
+   array.Add(s1);
+   array.Add(s2);
+
+   EXPECT_EQ(array.GetEntries(), 2);
+   EXPECT_EQ(array.GetLast(), 1);
+   EXPECT_FALSE(array.IsEmpty());
+
+   EXPECT_EQ(array.At(0), s1);
+   EXPECT_EQ(array.At(1), s2);
+   EXPECT_EQ(array.At(2), nullptr);
+}
+
+TEST(TObjArrayTest, AddFirstAndLast)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("first", "");
+   auto *s2 = new TNamed("second", "");
+
+   array.AddFirst(s1);
+   array.AddLast(s2);
+
+   EXPECT_EQ(array.GetEntries(), 2);
+   EXPECT_EQ(array.At(0), s1);
+   EXPECT_EQ(array.At(1), s2);
+}
+
+TEST(TObjArrayTest, AddAt)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("first", "");
+   auto *s2 = new TNamed("second", "");
+
+   array.AddAt(s1, 0);
+   array.AddAt(s2, 2);
+
+   EXPECT_EQ(array.GetEntries(), 2);
+   EXPECT_EQ(array.GetLast(), 2);
+
+   EXPECT_EQ(array.At(0), s1);
+   EXPECT_EQ(array.At(1), nullptr);
+   EXPECT_EQ(array.At(2), s2);
+}
+
+TEST(TObjArrayTest, AddAtAndExpand)
+{
+   TObjArray array(2);
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("element", "");
+
+   array.AddAtAndExpand(s1, 5);
+
+   EXPECT_EQ(array.GetEntries(), 1);
+   EXPECT_EQ(array.GetLast(), 5);
+   EXPECT_EQ(array.At(5), s1);
+}
+
+TEST(TObjArrayTest, AddAtFree)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("first", "");
+   auto *s2 = new TNamed("second", "");
+   auto *s3 = new TNamed("third", "");
+
+   array.AddAt(s1, 0);
+   array.AddAt(s2, 2);
+
+   Int_t idx = array.AddAtFree(s3);
+   EXPECT_EQ(idx, 1);
+   EXPECT_EQ(array.At(1), s3);
+   EXPECT_EQ(array.GetEntries(), 3);
+}
+
+TEST(TObjArrayTest, AddBeforeAndAfter)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s2 = new TNamed("second", "");
+   array.AddAt(s2, 2);
+
+   auto *s1 = new TNamed("first", "");
+   array.AddBefore(s2, s1);
+
+   auto *s3 = new TNamed("third", "");
+   array.AddAfter(s2, s3);
+
+   EXPECT_EQ(array.GetEntries(), 3);
+   EXPECT_EQ(array.At(1), s1);
+   EXPECT_EQ(array.At(2), s2);
+   EXPECT_EQ(array.At(3), s3);
+}
+
+TEST(TObjArrayTest, Remove)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("first", "");
+   auto *s2 = new TNamed("second", "");
+   auto *s3 = new TNamed("third", "");
+
+   array.Add(s1);
+   array.Add(s2);
+   array.Add(s3);
+
+   TObject *removed = array.Remove(s2);
+   EXPECT_EQ(removed, s2);
+   EXPECT_EQ(array.GetEntries(), 2);
+
+   EXPECT_EQ(array.At(0), s1);
+   EXPECT_EQ(array.At(1), nullptr);
+   EXPECT_EQ(array.At(2), s3);
+
+   delete removed;
+}
+
+TEST(TObjArrayTest, RemoveAt)
+{
+   // Test removing middle element
+   {
+      TObjArray array;
+      array.SetOwner(kTRUE);
+
+      auto *s1 = new TNamed("first", "");
+      auto *s2 = new TNamed("second", "");
+      auto *s3 = new TNamed("third", "");
+
+      array.Add(s1);
+      array.Add(s2);
+      array.Add(s3);
+      EXPECT_EQ(array.GetLast(), 2);
+
+      TObject *removed = array.RemoveAt(1);
+      EXPECT_EQ(removed, s2);
+      EXPECT_EQ(array.GetEntries(), 2);
+      EXPECT_EQ(array.At(0), s1);
+      EXPECT_EQ(array.At(1), nullptr);
+      EXPECT_EQ(array.At(2), s3);
+      EXPECT_EQ(array.GetLast(), 2);
+
+      delete removed;
+   }
+
+   // Test removing last element updates GetLast()
+   {
+      TObjArray array;
+      array.SetOwner(kTRUE);
+
+      auto *s1 = new TNamed("first", "");
+      auto *s2 = new TNamed("second", "");
+      auto *s3 = new TNamed("third", "");
+
+      array.Add(s1);
+      array.Add(s2);
+      array.Add(s3);
+      EXPECT_EQ(array.GetLast(), 2);
+
+      TObject *removed = array.RemoveAt(2);
+      EXPECT_EQ(removed, s3);
+      EXPECT_EQ(array.GetEntries(), 2);
+      EXPECT_EQ(array.At(0), s1);
+      EXPECT_EQ(array.At(1), s2);
+      EXPECT_EQ(array.At(2), nullptr);
+      EXPECT_EQ(array.GetLast(), 1);
+
+      delete removed;
+   }
+}
+
+TEST(TObjArrayTest, Compress)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   auto *s1 = new TNamed("first", "");
+   auto *s2 = new TNamed("second", "");
+   auto *s3 = new TNamed("third", "");
+
+   array.Add(s1);
+   array.Add(s2);
+   array.Add(s3);
+
+   // Remove the middle element, creating a gap: [s1, nullptr, s3]
+   TObject *removed = array.RemoveAt(1);
+   delete removed;
+
+   EXPECT_EQ(array.GetEntries(), 2);
+   EXPECT_EQ(array.At(0), s1);
+   EXPECT_EQ(array.At(1), nullptr);
+   EXPECT_EQ(array.At(2), s3);
+   EXPECT_EQ(array.GetLast(), 2);
+
+   // Compress closes the gap: [s1, s3, nullptr]
+   array.Compress();
+
+   EXPECT_EQ(array.GetEntries(), 2);
+   EXPECT_EQ(array.At(0), s1);
+   EXPECT_EQ(array.At(1), s3);
+   EXPECT_EQ(array.At(2), nullptr);
+   EXPECT_EQ(array.GetLast(), 1);
+}
+
+TEST(TObjArrayTest, ClearAndDelete)
+{
+   TrackObject::fgCount = 0;
+
+   // 1. Non-owner Clear(): removes pointers but does NOT delete objects
+   {
+      TObjArray array;
+      array.SetOwner(kFALSE);
+
+      auto *o1 = new TrackObject();
+      auto *o2 = new TrackObject();
+      array.Add(o1);
+      array.Add(o2);
+
+      EXPECT_EQ(TrackObject::fgCount, 2);
+      EXPECT_EQ(array.GetEntries(), 2);
+
+      array.Clear();
+      EXPECT_EQ(array.GetEntries(), 0);
+      EXPECT_EQ(TrackObject::fgCount, 2);
+
+      delete o1;
+      delete o2;
+      EXPECT_EQ(TrackObject::fgCount, 0);
+   }
+
+   // 2. Non-owner Delete(): explicitly deletes all heap objects
+   {
+      TObjArray array;
+      array.SetOwner(kFALSE);
+
+      array.Add(new TrackObject());
+      array.Add(new TrackObject());
+
+      EXPECT_EQ(TrackObject::fgCount, 2);
+      EXPECT_EQ(array.GetEntries(), 2);
+
+      array.Delete();
+      EXPECT_EQ(array.GetEntries(), 0);
+      EXPECT_EQ(TrackObject::fgCount, 0);
+   }
+
+   // 3. Owner Clear(): delegates to Delete(), deleting all objects
+   {
+      TObjArray array;
+      array.SetOwner(kTRUE);
+
+      array.Add(new TrackObject());
+      array.Add(new TrackObject());
+
+      EXPECT_EQ(TrackObject::fgCount, 2);
+      EXPECT_EQ(array.GetEntries(), 2);
+
+      array.Clear();
+      EXPECT_EQ(array.GetEntries(), 0);
+      EXPECT_EQ(TrackObject::fgCount, 0);
+   }
+}
+
+TEST(TObjArrayTest, Iteration)
+{
+   TObjArray array;
+   array.SetOwner(kTRUE);
+
+   array.Add(new TNamed("A", ""));
+   array.Add(new TNamed("B", ""));
+   array.Add(new TNamed("C", ""));
+
+   Int_t count = 0;
+   TIter next(&array);
+   TObject *obj;
+   while ((obj = next())) {
+      count++;
+   }
+
+   EXPECT_EQ(count, 3);
+}