test: Add assert mock to avoid death tests (#1947)

Fixes #1750

tests/common/util/MockAssert.cpp

@@ -0,0 +1,45 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2025, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "util/MockAssert.hpp"
+
+#include "util/Assert.hpp"
+
+#include <string>
+#include <string_view>
+
+namespace common::util {
+
+WithMockAssert::WithMockAssert()
+{
+    ::util::impl::OnAssert::setAction([](std::string_view m) { WithMockAssert::throwOnAssert(m); });
+}
+
+WithMockAssert::~WithMockAssert()
+{
+    ::util::impl::OnAssert::resetAction();
+}
+
+void
+WithMockAssert::throwOnAssert(std::string_view m)
+{
+    throw MockAssertException{.message = std::string{m}};
+}
+
+}  // namespace common::util