add unit test for BCD encoding/decoding
diff --git a/src/tests/test-helpers.c b/src/tests/test-helpers.c
new file mode 100644
index 0000000..e23f017
--- /dev/null
+++ b/src/tests/test-helpers.c
@@ -0,0 +1,35 @@
+#include "iu_helpers.h"
+#include "asn1helpers.h"
+
+#include <assert.h>
+#define ASSERT(x) assert(x)
+
+#include <osmocom/core/utils.h>
+
+void *talloc_asn1_ctx;
+
+/* use odd number of digits */
+const uint8_t imsi_encoded[] = { 0x10, 0x32, 0x54, 0x76, 0xF8 };
+const char imsi_decoded[] = "012345678";
+
+int main(int argc, char **argv)
+{
+ char outstr[32];
+ uint8_t outbuf[16];
+ int rc;
+
+ printf("pre-encoded: %s\n", osmo_hexdump_nospc(imsi_encoded,
+ sizeof(imsi_encoded)));
+ rc = decode_iu_bcd(outstr, sizeof(outstr), imsi_encoded,
+ sizeof(imsi_encoded));
+ ASSERT(rc >= 0);
+ printf("decoded: %s\n", outstr);
+ ASSERT(!strcmp(outstr, imsi_decoded));
+
+ rc = encode_iu_imsi(outbuf, sizeof(outbuf), imsi_decoded);
+ ASSERT(rc >= 0);
+ printf("re-encoded: %s\n", osmo_hexdump_nospc(outbuf, rc));
+ ASSERT(!memcmp(outbuf, imsi_encoded, sizeof(imsi_encoded)));
+
+ return 0;
+}