1 files changed, 17 insertions, 1 deletions
diff --git a/librecrypt_concat_mem_.c b/librecrypt_concat_mem_.c
index edc826a..296303e 100644
--- a/librecrypt_concat_mem_.c
+++ b/librecrypt_concat_mem_.c
@@ -12,10 +12,26 @@ extern inline void librecrypt_concat_mem_(struct concat_state *state, const char
 int
 main(void)
 {
+	char buf[5];
+	struct concat_state state = {buf, sizeof(buf), 0u};
+
 	SET_UP_ALARM();
 	INIT_RESOURCE_TEST();
 
-	/* TODO test */
+	memset(buf, 'x', sizeof(buf));
+
+	librecrypt_concat_mem_(&state, "abcdef", 6u);
+	assert(!memcmp(buf, "abcd\0", sizeof(buf)));
+	assert(state.buf == &buf[4u]);
+	assert(state.size == 1u);
+	assert(state.len == 6u);
+	librecrypt_concat_mem_(&state, "z", 1u);
+	assert(!memcmp(buf, "abcd\0", sizeof(buf)));
+	assert(state.len == 7u);
+
+	state = (struct concat_state){NULL, 0u, 0u};
+	librecrypt_concat_mem_(&state, "abc", 3u);
+	assert(state.len == 3u);
 
 	STOP_RESOURCE_TEST();
 	return 0;