From 17bbf3e6f402908d308db8fc98eec851b72c1073 Mon Sep 17 00:00:00 2001
From: Andrei Litvin <andy314@gmail.com>
Date: Thu, 6 Jan 2022 14:52:10 -0500
Subject: [PATCH] Make "contains" take a const argument in intrusive list

---
 src/lib/support/IntrusiveList.h             |  8 +++--
 src/lib/support/tests/TestIntrusiveList.cpp | 40 ++++++++++++++++++++-
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/src/lib/support/IntrusiveList.h b/src/lib/support/IntrusiveList.h
index 4d9bc3e3b6ceae..7555b1659aa873 100644
--- a/src/lib/support/IntrusiveList.h
+++ b/src/lib/support/IntrusiveList.h
@@ -202,7 +202,7 @@ class IntrusiveListBase
     void InsertAfter(IteratorBase pos, IntrusiveListNodeBase * node) { pos.mCurrent->Append(node); }
     void Remove(IntrusiveListNodeBase * node) { node->Remove(); }
 
-    bool Contains(IntrusiveListNodeBase * node) const
+    bool Contains(const IntrusiveListNodeBase * node) const
     {
         for (auto & iter : *this)
         {
@@ -225,8 +225,12 @@ class IntrusiveListBaseHook
 {
 public:
     static_assert(std::is_base_of<IntrusiveListNodeBase, T>::value, "T must be derived from IntrusiveListNodeBase");
+
     static T * ToObject(IntrusiveListNodeBase * node) { return static_cast<T *>(node); }
+    static const T * ToObject(const IntrusiveListNodeBase * node) { return static_cast<T *>(node); }
+
     static IntrusiveListNodeBase * ToNode(T * object) { return static_cast<IntrusiveListNodeBase *>(object); }
+    static const IntrusiveListNodeBase * ToNode(const T * object) { return static_cast<const IntrusiveListNodeBase *>(object); }
 };
 
 /// A double-linked list where the data is stored together with the previous/next pointers for cache efficiency / and compactness.
@@ -289,7 +293,7 @@ class IntrusiveList : public IntrusiveListBase
     void InsertBefore(Iterator pos, T * value) { IntrusiveListBase::InsertBefore(pos, Hook::ToNode(value)); }
     void InsertAfter(Iterator pos, T * value) { IntrusiveListBase::InsertAfter(pos, Hook::ToNode(value)); }
     void Remove(T * value) { IntrusiveListBase::Remove(Hook::ToNode(value)); }
-    bool Contains(T * value) const { return IntrusiveListBase::Contains(Hook::ToNode(value)); }
+    bool Contains(const T * value) const { return IntrusiveListBase::Contains(Hook::ToNode(value)); }
 };
 
 } // namespace chip
diff --git a/src/lib/support/tests/TestIntrusiveList.cpp b/src/lib/support/tests/TestIntrusiveList.cpp
index 7e9bbb73051903..f65eb8557ba94a 100644
--- a/src/lib/support/tests/TestIntrusiveList.cpp
+++ b/src/lib/support/tests/TestIntrusiveList.cpp
@@ -97,6 +97,40 @@ void TestIntrusiveListRandom(nlTestSuite * inSuite, void * inContext)
     }
 }
 
+void TestContains(nlTestSuite * inSuite, void * inContext)
+{
+    ListNode a, b, c;
+    IntrusiveList<ListNode> list;
+
+    NL_TEST_ASSERT(inSuite, !list.Contains(&a));
+    NL_TEST_ASSERT(inSuite, !list.Contains(&b));
+    NL_TEST_ASSERT(inSuite, !list.Contains(&c));
+
+    list.PushBack(&a);
+    list.PushFront(&c);
+
+    NL_TEST_ASSERT(inSuite, list.Contains(&a));
+    NL_TEST_ASSERT(inSuite, !list.Contains(&b));
+    NL_TEST_ASSERT(inSuite, list.Contains(&c));
+
+    list.PushBack(&b);
+
+    NL_TEST_ASSERT(inSuite, list.Contains(&a));
+    NL_TEST_ASSERT(inSuite, list.Contains(&b));
+    NL_TEST_ASSERT(inSuite, list.Contains(&c));
+
+    list.Remove(&a);
+    list.Remove(&c);
+
+    NL_TEST_ASSERT(inSuite, !list.Contains(&a));
+    NL_TEST_ASSERT(inSuite, list.Contains(&b));
+    NL_TEST_ASSERT(inSuite, !list.Contains(&c));
+
+    // all nodes have to be removed from the list on destruction. Lists do NOT do
+    // this automatically
+    list.Remove(&b);
+}
+
 int Setup(void * inContext)
 {
     return SUCCESS;
@@ -113,7 +147,11 @@ int Teardown(void * inContext)
 /**
  *   Test Suite. It lists all the test functions.
  */
-static const nlTest sTests[] = { NL_TEST_DEF_FN(TestIntrusiveListRandom), NL_TEST_SENTINEL() };
+static const nlTest sTests[] = {
+    NL_TEST_DEF_FN(TestIntrusiveListRandom), //
+    NL_TEST_DEF_FN(TestContains),            //
+    NL_TEST_SENTINEL(),                      //
+};
 
 int TestIntrusiveList()
 {