diff --git a/include/r3_gvc.h b/include/r3_gvc.h
new file mode 100644
index 0000000..012470d
--- /dev/null
+++ b/include/r3_gvc.h
@@ -0,0 +1,15 @@
+/*
+ * r3_gvc.h
+ * Copyright (C) 2014 c9s <c9s@c9smba.local>
+ *
+ * Distributed under terms of the MIT license.
+ */
+
+#ifndef R3_GVC_H
+#define R3_GVC_H
+
+#include <gvc.h>
+
+void r3_tree_build_ag_nodes(Agraph_t * g, Agnode_t * ag_parent_node, node * n, int node_cnt);
+
+#endif /* !R3_GVC_H */
diff --git a/tests/check_slug.c b/tests/check_slug.c
new file mode 100644
index 0000000..2a78431
--- /dev/null
+++ b/tests/check_slug.c
@@ -0,0 +1,104 @@
+/*
+ * check_slug.c
+ * Copyright (C) 2014 c9s <c9s@c9smba.local>
+ *
+ * Distributed under terms of the MIT license.
+ */
+#include "config.h"
+#include <stdio.h>
+#include <check.h>
+#include <stdlib.h>
+#include "r3.h"
+#include "r3_str.h"
+#include "str_array.h"
+
+START_TEST (test_compile_slug)
+{
+    char * path = "/user/{id}";
+    ck_assert_str_eq( compile_slug(path, strlen(path) ) , "/user/([^/]+)" );
+
+    char * path2 = "/what/{id}-foo";
+    ck_assert_str_eq( compile_slug(path2, strlen(path2) ) , "/what/([^/]+)-foo" );
+}
+END_TEST
+
+START_TEST (test_contains_slug)
+{
+    char * path = "/user/{id}/{name}";
+    ck_assert( contains_slug(path) );
+}
+END_TEST
+
+START_TEST (test_find_slug_pattern)
+{
+    int len;
+    char * namerex = find_slug_pattern("{name:\\s+}", &len);
+    ck_assert( strncmp(namerex, "\\s+", len) == 0 );
+}
+END_TEST
+
+
+START_TEST (test_find_slug_placeholder)
+{
+    int slug_len = 0;
+    char * slug = find_slug_placeholder("/user/{name:\\s+}/to/{id}", &slug_len);
+    // printf("slug: '%s'\n", strndup(slug, slug_len) );
+    ck_assert( strncmp(slug, "{name:\\s+}", slug_len) == 0 );
+}
+END_TEST
+
+START_TEST (test_inside_slug)
+{
+    int slug_len = 0;
+    char * pattern = "/user/{name:\\s+}/to/{id}";
+    char * offset = strchr(pattern, '{') + 2;
+    ck_assert( inside_slug(pattern, strlen(pattern), offset) );
+    ck_assert( *(inside_slug(pattern, strlen(pattern), offset)) == '{' );
+    ck_assert( ! inside_slug(pattern, strlen(pattern), pattern) );
+}
+END_TEST
+
+START_TEST (test_count_slug)
+{
+    int slug_len = 0;
+    char * pattern = "/user/{name:\\s+}/to/{id}";
+    ck_assert_int_eq( count_slug(pattern, strlen(pattern) ), 2 );
+
+    char * pattern2 = "/user/{name:\\d{3}}/to/{id}";
+    ck_assert_int_eq( count_slug(pattern2, strlen(pattern) ), 2 );
+}
+END_TEST
+
+START_TEST (test_find_slug_placeholder_with_broken_slug)
+{
+    int slug_len = 0;
+    char * slug = find_slug_placeholder("/user/{name:\\s+/to/{id", &slug_len);
+    ck_assert(! slug);
+}
+END_TEST
+
+
+Suite* r3_suite (void) {
+        Suite *suite = suite_create("slug test");
+        TCase *tcase = tcase_create("test_slug");
+        tcase_add_test(tcase, test_contains_slug);
+        tcase_add_test(tcase, test_inside_slug);
+        tcase_add_test(tcase, test_find_slug_pattern);
+        tcase_add_test(tcase, test_find_slug_placeholder);
+        tcase_add_test(tcase, test_find_slug_placeholder_with_broken_slug);
+        tcase_add_test(tcase, test_count_slug);
+        tcase_add_test(tcase, test_compile_slug);
+
+        suite_add_tcase(suite, tcase);
+        return suite;
+}
+
+int main (int argc, char *argv[]) {
+        int number_failed;
+        Suite *suite = r3_suite();
+        SRunner *runner = srunner_create(suite);
+        srunner_run_all(runner, CK_NORMAL);
+        number_failed = srunner_ntests_failed(runner);
+        srunner_free(runner);
+        return number_failed;
+}