test: convert tuple_to_array to gtest

Change-Id: Ie110fba8f1961ba0e1a46c670d98a2351a46d061
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/test/Makefile.am b/test/Makefile.am
index 500f7c5..e064504 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,6 +1,7 @@
 if WANT_LIBSDBUSPLUS
 
 AM_CPPFLAGS = -I$(top_srcdir) $(GTEST_CPPFLAGS)
+gtest_ldflags = -lgtest -lgtest_main
 check_PROGRAMS =
 
 TESTS = $(check_PROGRAMS)
@@ -27,12 +28,13 @@
 
 check_PROGRAMS += utility_tuple_to_array
 utility_tuple_to_array_SOURCES = utility/tuple_to_array.cpp
+utility_tuple_to_array_LDFLAGS = $(gtest_ldflags)
 
 check_PROGRAMS += utility_type_traits
 utility_type_traits_SOURCES = utility/type_traits.cpp
 
 check_PROGRAMS += vtable_vtable
 vtable_vtable_SOURCES = vtable/vtable.cpp vtable/vtable_c.c
-vtable_vtable_LDFLAGS = -lgtest -lgtest_main
+vtable_vtable_LDFLAGS = $(gtest_ldflags)
 
 endif
diff --git a/test/utility/tuple_to_array.cpp b/test/utility/tuple_to_array.cpp
index e7472f9..bf73783 100644
--- a/test/utility/tuple_to_array.cpp
+++ b/test/utility/tuple_to_array.cpp
@@ -1,17 +1,18 @@
 #include <sdbusplus/utility/tuple_to_array.hpp>
-#include <cassert>
+#include <gtest/gtest.h>
 
-int main()
+TEST(TupleToArray, Test3Chars)
 {
     std::array<char, 3> a{'a', 'b', 'c'};
     auto t = std::make_tuple('a', 'b', 'c');
 
-    assert(a == sdbusplus::utility::tuple_to_array(std::move(t)));
+    ASSERT_EQ(a, sdbusplus::utility::tuple_to_array(std::move(t)));
+}
 
+TEST(TupleToArray, Test4Ints)
+{
     std::array<int, 4> b{1, 2, 3, 4};
     auto t2 = std::make_tuple(1, 2, 3, 4);
 
-    assert(b == sdbusplus::utility::tuple_to_array(std::move(t2)));
-
-    return 0;
+    ASSERT_EQ(b, sdbusplus::utility::tuple_to_array(std::move(t2)));
 }