start to bring up testing

tests/utests/schema/test_schema.c

@@ -1887,6 +1887,113 @@ test_lysc_path(void **state)
     free(path);
 }
 
+static void
+test_lysc_backlinks(void **state)
+{
+    const char *expect1[] = {
+        "/b:my_extref_list/my_extref",
+        "/a:refstr",
+        "/a:refnum",
+        "/b:my_extref_list/my_extref_union",
+        NULL
+    };
+    const char *expect2[] = {
+        "/b:my_extref_list/my_extref",
+        "/a:refstr",
+        "/b:my_extref_list/my_extref_union",
+        NULL
+    };
+    const char *expect3[] = {
+        "/b:my_extref_list/my_extref",
+        "/a:refstr",
+        "/a:refnum",
+        "/b:my_extref_list/my_extref_union",
+        NULL
+    };
+    struct {
+        const char *match_path;
+        ly_bool match_ancestors;
+        const char **expected_paths;
+    } tests[] = {
+        { NULL, 0, expect1 },
+        { "/a:my_list/my_leaf_string", 0, expect2 },
+        { "/a:my_list/", 1, expect3 }
+    };
+    const char *str;
+    size_t      i;
+
+    str = "module a {\n"
+          "    namespace urn:a;\n"
+          "    prefix a;\n"
+          "    list my_list {\n"
+          "        key my_leaf_string;\n"
+          "        leaf my_leaf_string {\n"
+          "            type string;\n"
+          "        }\n"
+          "        leaf my_leaf_number {\n"
+          "            type uint32;\n"
+          "        }\n"
+          "    }\n"
+          "    leaf refstr {\n"
+          "        type leafref {\n"
+          "            path \"../my_list/my_leaf_string\";\n"
+          "        }\n"
+          "    }\n"
+          "    leaf refnum {\n"
+          "        type leafref {\n"
+          "            path \"../my_list/my_leaf_number\";\n"
+          "        }\n"
+          "    }\n"
+          "}\n";
+
+    assert_int_equal(lys_parse_mem(UTEST_LYCTX, str, LYS_IN_YANG, NULL), LY_SUCCESS);
+    CHECK_LOG_CTX(NULL, NULL, 0);
+
+    str = "module b {\n"
+          "    urn:b;\n"
+          "    import a {\n"
+          "        prefix a;\n"
+          "    }\n"
+          "    list my_extref_list {\n"
+          "        key my_leaf_string;\n"
+          "        leaf my_leaf_string {\n"
+          "            type string;\n"
+          "        }\n"
+          "        leaf my_extref {\n"
+          "            type leafref {\n"
+          "            path \"/a:my_list/a:my_leaf_string\";\n"
+          "        }\n"
+          "    }\n"
+          "    leaf my_extref_union {\n"
+          "        type union {\n"
+          "            type leafref {\n"
+          "                path \"/a:my_list/a:my_leaf_string\";\n"
+          "            }\n"
+          "            type leafref {\n"
+          "                path \"/a:my_list/a:my_leaf_number\";\n"
+          "            }\n"
+          "            type uint32;\n"
+          "         }\n"
+          "    }\n"
+          "}\n";
+    assert_int_equal(lys_parse_mem(UTEST_LYCTX, str, LYS_IN_YANG, NULL), LY_SUCCESS);
+    CHECK_LOG_CTX(NULL, NULL, 0);
+
+    for (i=0; i<sizeof(tests)/sizeof(*tests); i++) {
+        const struct lysc_node *node = NULL;
+        struct ly_set *set = NULL;
+
+        if (tests[i].match_path) {
+            assert_non_null(lys_find_path(UTEST_LYCTX, NULL, tests[i].match_path, 0));
+        }
+
+        assert_int_equal(lys_find_backlinks(UTEST_LYCTX, node, tests[i].match_ancestors, &set), LY_SUCCESS);
+
+        /* XXX: Match paths */
+        ly_set_free(set, NULL);
+    }
+}
+
 int
 main(void)
 {
@@ -1909,6 +2016,7 @@ main(void)
         UTEST(test_extension_compile),
         UTEST(test_ext_recursive),
         UTEST(test_lysc_path),
+        UTEST(test_lysc_backlinks)
     };
 
     return cmocka_run_group_tests(tests, NULL, NULL);