diff --git a/dependencies/leaf/convenience/leaf_ns.h b/dependencies/leaf/convenience/leaf_ns.h
index 8f5fd88..80771ca 100644
--- a/dependencies/leaf/convenience/leaf_ns.h
+++ b/dependencies/leaf/convenience/leaf_ns.h
@@ -10,11 +10,7 @@ Copyright:
 
 
 /// Use leaf:: instead of boost::leaf for convenience
-namespace leaf {
-
-	using namespace boost::leaf;
-
-}
+namespace leaf = boost::leaf;
 
 
 #endif
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e82bbb5..f0b66b5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -76,4 +76,5 @@ add_subdirectory(libdebug)
 add_subdirectory(rconfig)
 add_subdirectory(ui)
 add_subdirectory(test_all)
+add_subdirectory(test_helpers)
 
diff --git a/src/test_helpers/CMakeLists.txt b/src/test_helpers/CMakeLists.txt
new file mode 100644
index 0000000..5ef749c
--- /dev/null
+++ b/src/test_helpers/CMakeLists.txt
@@ -0,0 +1,21 @@
+###############################################################################
+# License: BSD Zero Clause License file
+# Copyright:
+#   (C) 2022 Alexander Shaduri <ashaduri@gmail.com>
+###############################################################################
+
+if (NOT APP_BUILD_TESTS)
+    set_directory_properties(PROPERTIES EXCLUDE_FROM_ALL true)
+else()
+    set_directory_properties(PROPERTIES EXCLUDE_FROM_ALL false)
+endif()
+
+
+add_library(test_helpers INTERFACE)
+
+# Relative sources are allowed only since cmake 3.13.
+target_sources(test_helpers INTERFACE
+	${CMAKE_CURRENT_SOURCE_DIR}/test_helpers.h
+)
+
+target_include_directories(test_helpers INTERFACE "${CMAKE_SOURCE_DIR}/src")
diff --git a/src/test_helpers/test_helpers.h b/src/test_helpers/test_helpers.h
new file mode 100644
index 0000000..bccd1d7
--- /dev/null
+++ b/src/test_helpers/test_helpers.h
@@ -0,0 +1,50 @@
+/******************************************************************************
+License: GNU General Public License v3.0 only
+Copyright:
+	(C) 2022 Alexander Shaduri <ashaduri@gmail.com>
+******************************************************************************/
+/// \file
+/// \author Alexander Shaduri
+/// \ingroup test_helpers
+/// \weakgroup test_helpers
+/// @{
+
+#ifndef TEST_HELPERS_H
+#define TEST_HELPERS_H
+
+#include "leaf_ns.h"
+
+#include <utility>
+
+
+
+/// From https://github.com/boostorg/leaf/issues/42
+/// \tparam TryBlock A lambda
+/// \tparam E... Any number of error values with _different_ types.
+/// \return true if try_block fails AND produces at least one error object that
+/// compares equal to the specified error value of the same type.
+template<class... E, class TryBlock>
+bool try_expect_errors(TryBlock&& try_block, E&& ... expected)
+{
+	return leaf::try_handle_all(
+		[&]() -> leaf::result<bool> {
+			auto r = std::forward<TryBlock>(try_block)();
+			if (r) {
+				return false;
+			}
+			return r.error();
+		},
+		[&](E& e) {
+			return e == std::forward<E>(expected);
+		}...,
+		[] {
+			return false;
+		});
+}
+
+
+
+
+#endif
+
+/// @}