Added tests for coll_reg (#1700)

Changes to coll_reg

Co-authored-by: Welling <awelling@ctr2-alola-login-01.amd.com>

test/common/CollRegUtils.hpp

@@ -0,0 +1,52 @@
+/*************************************************************************
+ * Copyright (c) 2023 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * See LICENSE.txt for license information
+ ************************************************************************/
+
+#include <gtest/gtest.h>
+#include <rccl/rccl.h>
+#include <comm.h>
+#include <transport.h>
+#include "TestBed.hpp"
+
+ncclResult_t registerCheckP2PConnection(struct ncclComm* comm, struct ncclConnector* conn, struct ncclTopoGraph* graph, int peer, bool* needReg);
+
+// Global mock transport definition (outside any namespace)
+static ncclResult_t mockCanConnect(int* result, struct ncclComm*, struct ncclTopoGraph*,
+  struct ncclPeerInfo*, struct ncclPeerInfo*) {
+*result = 1;
+return ncclSuccess;
+}
+
+static ncclResult_t mockCanConnectFalse(int* result, struct ncclComm*, struct ncclTopoGraph*,
+  struct ncclPeerInfo*, struct ncclPeerInfo*) {
+*result = 0;  // Simulate failure to connect
+return ncclSuccess;
+}
+
+static struct ncclTransport mockTransport = {
+.canConnect = mockCanConnect,
+};
+
+struct ncclTransport* ncclTransports[] = {
+&mockTransport,
+nullptr
+};
+
+struct ScopedCanConnectOverride {
+  struct ncclTransport* transport;
+  ncclResult_t (*originalFn)(int*, struct ncclComm*, struct ncclTopoGraph*,
+                             struct ncclPeerInfo*, struct ncclPeerInfo*);
+
+  ScopedCanConnectOverride(struct ncclTransport* t,
+                           ncclResult_t (*mockFn)(int*, struct ncclComm*, struct ncclTopoGraph*,
+                                                  struct ncclPeerInfo*, struct ncclPeerInfo*))
+      : transport(t), originalFn(t->canConnect) {
+    t->canConnect = mockFn;
+  }
+
+  ~ScopedCanConnectOverride() {
+    transport->canConnect = originalFn;
+  }
+};