diff --git a/tests/utests/CMakeLists.txt b/tests/utests/CMakeLists.txt
index 5180113..dcf1910 100644
--- a/tests/utests/CMakeLists.txt
+++ b/tests/utests/CMakeLists.txt
@@ -17,6 +17,7 @@
 ly_add_utest(NAME new SOURCES data/test_new.c)
 ly_add_utest(NAME parser_xml SOURCES data/test_parser_xml.c)
 ly_add_utest(NAME printer_xml SOURCES data/test_printer_xml.c)
+ly_add_utest(NAME parser_json SOURCES data/test_parser_json.c)
 ly_add_utest(NAME lyb SOURCES data/test_lyb.c)
 ly_add_utest(NAME validation SOURCES data/test_validation.c)
 ly_add_utest(NAME types SOURCES data/test_types.c)
diff --git a/tests/utests/data/test_new.c b/tests/utests/data/test_new.c
index 21eb126..50a7740 100644
--- a/tests/utests/data/test_new.c
+++ b/tests/utests/data/test_new.c
@@ -196,14 +196,14 @@
     opq = (struct lyd_node_opaq *)root;
     assert_string_equal(opq->name, "node1");
     assert_string_equal(opq->value, "");
-    assert_string_equal(opq->prefix.ns, "my-module");
+    assert_string_equal(opq->prefix.module_name, "my-module");
 
     assert_int_equal(lyd_new_opaq(root, NULL, "node2", "value", "my-module2", &node), LY_SUCCESS);
     assert_null(node->schema);
     opq = (struct lyd_node_opaq *)node;
     assert_string_equal(opq->name, "node2");
     assert_string_equal(opq->value, "value");
-    assert_string_equal(opq->prefix.ns, "my-module2");
+    assert_string_equal(opq->prefix.module_name, "my-module2");
     assert_ptr_equal(opq->parent, root);
 
     lyd_free_tree(root);
diff --git a/tests/utests/data/test_parser_json.c b/tests/utests/data/test_parser_json.c
new file mode 100644
index 0000000..7539dc7
--- /dev/null
+++ b/tests/utests/data/test_parser_json.c
@@ -0,0 +1,809 @@
+/*
+ * @file test_parser_xml.c
+ * @author: Radek Krejci <rkrejci@cesnet.cz>
+ * @brief unit tests for functions from parser_xml.c
+ *
+ * Copyright (c) 2019 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <setjmp.h>
+#include <cmocka.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include "context.h"
+#include "parser.h"
+#include "parser_data.h"
+#include "printer.h"
+#include "printer_data.h"
+#include "tests/config.h"
+#include "tree_data_internal.h"
+#include "tree_schema.h"
+
+#define BUFSIZE 1024
+char logbuf[BUFSIZE] = {0};
+int store = -1; /* negative for infinite logging, positive for limited logging */
+
+struct ly_ctx *ctx; /* context for tests */
+
+/* set to 0 to printing error messages to stderr instead of checking them in code */
+#define ENABLE_LOGGER_CHECKING 1
+
+#if ENABLE_LOGGER_CHECKING
+static void
+logger(LY_LOG_LEVEL level, const char *msg, const char *path)
+{
+    (void) level; /* unused */
+    if (store) {
+        if (path && path[0]) {
+            snprintf(logbuf, BUFSIZE - 1, "%s %s", msg, path);
+        } else {
+            strncpy(logbuf, msg, BUFSIZE - 1);
+        }
+        if (store > 0) {
+            --store;
+        }
+    }
+}
+#endif
+
+static int
+setup(void **state)
+{
+    (void) state; /* unused */
+
+    const char *schema_a = "module a {namespace urn:tests:a;prefix a;yang-version 1.1; import ietf-yang-metadata {prefix md;}"
+            "md:annotation hint { type int8;}"
+            "list l1 { key \"a b c\"; leaf a {type string;} leaf b {type string;} leaf c {type int16;} leaf d {type string;}}"
+            "leaf foo { type string;}"
+            "container c {"
+                "leaf x {type string;}"
+                "action act { input { leaf al {type string;} } output { leaf al {type uint8;} } }"
+                "notification n1 { leaf nl {type string;} }"
+            "}"
+            "container cp {presence \"container switch\"; leaf y {type string;} leaf z {type int8;}}"
+            "anydata any {config false;}"
+            "leaf-list ll1 { type uint8; }"
+            "leaf foo2 { type string; default \"default-val\"; }"
+            "leaf foo3 { type uint32; }"
+            "notification n2;}";
+    const struct lys_module *mod;
+
+#if ENABLE_LOGGER_CHECKING
+    ly_set_log_clb(logger, 1);
+#endif
+
+    assert_int_equal(LY_SUCCESS, ly_ctx_new(TESTS_DIR_MODULES_YANG, 0, &ctx));
+    assert_non_null(ly_ctx_load_module(ctx, "ietf-netconf-with-defaults", "2011-06-01"));
+    assert_non_null((mod = ly_ctx_load_module(ctx, "ietf-netconf", "2011-06-01")));
+    assert_int_equal(LY_SUCCESS, lys_feature_enable(mod, "writable-running"));
+    assert_int_equal(LY_SUCCESS, lys_parse_mem(ctx, schema_a, LYS_IN_YANG, NULL));
+
+    return 0;
+}
+
+static int
+teardown(void **state)
+{
+#if ENABLE_LOGGER_CHECKING
+    if (*state) {
+        fprintf(stderr, "%s\n", logbuf);
+    }
+#else
+    (void) state; /* unused */
+#endif
+
+    ly_ctx_destroy(ctx, NULL);
+    ctx = NULL;
+
+    return 0;
+}
+
+void
+logbuf_clean(void)
+{
+    logbuf[0] = '\0';
+}
+
+#if ENABLE_LOGGER_CHECKING
+#   define logbuf_assert(str) assert_string_equal(logbuf, str)
+#else
+#   define logbuf_assert(str)
+#endif
+
+static void
+test_leaf(void **state)
+{
+    *state = test_leaf;
+
+    const char *data = "{\"a:foo\":\"foo value\"}";
+    struct lyd_node *tree;
+    struct lyd_node_term *leaf;
+
+    char *printed;
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&printed, 0, &out));
+
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAF, tree->schema->nodetype);
+    assert_string_equal("foo", tree->schema->name);
+    leaf = (struct lyd_node_term*)tree;
+    assert_string_equal("foo value", leaf->value.original);
+
+    assert_int_equal(LYS_LEAF, tree->next->next->schema->nodetype);
+    assert_string_equal("foo2", tree->next->next->schema->name);
+    leaf = (struct lyd_node_term*)tree->next->next;
+    assert_string_equal("default-val", leaf->value.original);
+    assert_true(leaf->flags & LYD_DEFAULT);
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(printed, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* make foo2 explicit */
+    data = "{\"a:foo2\":\"default-val\"}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAF, tree->schema->nodetype);
+    assert_string_equal("foo2", tree->schema->name);
+    leaf = (struct lyd_node_term*)tree;
+    assert_string_equal("default-val", leaf->value.original);
+    assert_false(leaf->flags & LYD_DEFAULT);
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(printed, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* parse foo2 but make it implicit */
+    data = "{\"a:foo2\" : \"default-val\", \"@a:foo2\" : { \"ietf-netconf-with-defaults:default\" : true }}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAF, tree->schema->nodetype);
+    assert_string_equal("foo2", tree->schema->name);
+    leaf = (struct lyd_node_term*)tree;
+    assert_string_equal("default-val", leaf->value.original);
+    assert_true(leaf->flags & LYD_DEFAULT);
+
+    lyd_free_all(tree);
+
+    /* multiple meatadata hint and unknown metadata xxx supposed to be skipped since it is from missing schema */
+    data = "{\"@a:foo\" : { \"a:hint\" : 1, \"a:hint\" : 2, \"x:xxx\" : { \"value\" : \"/x:no/x:yes\" }}, \"a:foo\" : \"xxx\"}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAF, tree->schema->nodetype);
+    assert_string_equal("foo", tree->schema->name);
+    assert_non_null(tree->meta);
+    assert_string_equal("hint", tree->meta->name);
+    assert_int_equal(LY_TYPE_INT8, tree->meta->value.realtype->basetype);
+    assert_string_equal("1", tree->meta->value.original);
+    assert_int_equal(1, tree->meta->value.int8);
+    assert_ptr_equal(tree, tree->meta->parent);
+    assert_non_null(tree->meta->next);
+    assert_string_equal("hint", tree->meta->next->name);
+    assert_int_equal(LY_TYPE_INT8, tree->meta->next->value.realtype->basetype);
+    assert_string_equal("2", tree->meta->next->value.original);
+    assert_int_equal(2, tree->meta->next->value.int8);
+    assert_ptr_equal(tree, tree->meta->next->parent);
+    assert_null(tree->meta->next->next);
+
+    ly_out_free(out, NULL, 1);
+    lyd_free_all(tree);
+
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_STRICT, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Unknown (or not implemented) YANG module \"x\" for metadata \"x:xxx\". /a:foo");
+
+    /* missing referenced metadata node */
+    data = "{\"@a:foo\" : { \"a:hint\" : 1 }}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Missing JSON data instance to be coupled with @a:foo metadata. /");
+
+    /* missing namespace for meatadata*/
+    data = "{\"a:foo\" : \"value\", \"@a:foo\" : { \"hint\" : 1 }}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Metadata in JSON must be namespace-qualified, missing prefix for \"hint\". /a:foo");
+
+    *state = NULL;
+}
+
+static void
+test_leaflist(void **state)
+{
+    *state = test_leaflist;
+
+    const char *data = "{ \"a:ll1\" : [10,11] }";
+    struct lyd_node *tree;
+    struct lyd_node_term *ll;
+
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAFLIST, tree->schema->nodetype);
+    assert_string_equal("ll1", tree->schema->name);
+    ll = (struct lyd_node_term*)tree;
+    assert_string_equal("10", ll->value.original);
+
+    assert_non_null(tree->next);
+    assert_int_equal(LYS_LEAFLIST, tree->next->schema->nodetype);
+    assert_string_equal("ll1", tree->next->schema->name);
+    ll = (struct lyd_node_term*)tree->next;
+    assert_string_equal("11", ll->value.original);
+
+    lyd_free_all(tree);
+
+    /* simple metadata */
+    data = "{ \"a:ll1\" : [10,11], \"@a:ll1\" : [null, {\"a:hint\" : 2}] }";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAFLIST, tree->schema->nodetype);
+    assert_string_equal("ll1", tree->schema->name);
+    ll = (struct lyd_node_term*)tree;
+    assert_string_equal("10", ll->value.original);
+    assert_null(ll->meta);
+
+    assert_non_null(tree->next);
+    assert_int_equal(LYS_LEAFLIST, tree->next->schema->nodetype);
+    assert_string_equal("ll1", tree->next->schema->name);
+    ll = (struct lyd_node_term*)tree->next;
+    assert_string_equal("11", ll->value.original);
+    assert_non_null(ll->meta);
+    assert_string_equal("2", ll->meta->value.original);
+    assert_null(ll->meta->next);
+
+    lyd_free_all(tree);
+
+        /* multiple meatadata hint and unknown metadata xxx supposed to be skipped since it is from missing schema */
+    data = "{\"@a:ll1\" : [{\"a:hint\" : 1, \"x:xxx\" :  { \"value\" : \"/x:no/x:yes\" }, \"a:hint\" : 10},null,{\"a:hint\" : 3}], \"a:ll1\" : [1,2,3]}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LEAFLIST, tree->schema->nodetype);
+    assert_string_equal("ll1", tree->schema->name);
+    ll = (struct lyd_node_term*)tree;
+    assert_string_equal("1", ll->value.original);
+    assert_non_null(ll->meta);
+    assert_string_equal("hint", ll->meta->name);
+    assert_int_equal(LY_TYPE_INT8, ll->meta->value.realtype->basetype);
+    assert_string_equal("1", ll->meta->value.original);
+    assert_int_equal(1, ll->meta->value.int8);
+    assert_ptr_equal(ll, ll->meta->parent);
+    assert_non_null(ll->meta->next);
+    assert_string_equal("hint", ll->meta->next->name);
+    assert_int_equal(LY_TYPE_INT8, ll->meta->next->value.realtype->basetype);
+    assert_string_equal("10", ll->meta->next->value.original);
+    assert_int_equal(10, ll->meta->next->value.int8);
+    assert_ptr_equal(ll, ll->meta->next->parent);
+    assert_null(ll->meta->next->next);
+
+    assert_non_null(tree->next);
+    assert_int_equal(LYS_LEAFLIST, tree->next->schema->nodetype);
+    assert_string_equal("ll1", tree->next->schema->name);
+    ll = (struct lyd_node_term*)tree->next;
+    assert_string_equal("2", ll->value.original);
+    assert_null(ll->meta);
+
+    assert_non_null(tree->next->next);
+    assert_int_equal(LYS_LEAFLIST, tree->next->next->schema->nodetype);
+    assert_string_equal("ll1", tree->next->next->schema->name);
+    ll = (struct lyd_node_term*)tree->next->next;
+    assert_string_equal("3", ll->value.original);
+    assert_non_null(ll->meta);
+    assert_string_equal("hint", ll->meta->name);
+    assert_int_equal(LY_TYPE_INT8, ll->meta->value.realtype->basetype);
+    assert_string_equal("3", ll->meta->value.original);
+    assert_int_equal(3, ll->meta->value.int8);
+    assert_ptr_equal(ll, ll->meta->parent);
+    assert_null(ll->meta->next);
+
+    lyd_free_all(tree);
+
+    /* missing referenced metadata node */
+    data = "{\"@a:ll1\":[{\"a:hint\":1}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Missing JSON data instance to be coupled with @a:ll1 metadata. /");
+
+    data = "{\"a:ll1\":[1],\"@a:ll1\":[{\"a:hint\":1},{\"a:hint\":2}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Missing JSON data instance no. 2 of a:ll1 to be coupled with metadata. /");
+
+    data = "{\"@a:ll1\":[{\"a:hint\":1},{\"a:hint\":2},{\"a:hint\":3}],\"a:ll1\" : [1, 2]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Missing 3rd JSON data instance to be coupled with @a:ll1 metadata. /");
+
+    *state = NULL;
+}
+
+static void
+test_anydata(void **state)
+{
+    *state = test_anydata;
+
+    const char *data;
+    char *str;
+    struct lyd_node *tree;
+
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
+
+    data = "{\"a:any\":{\"x:element1\":{\"element2\":\"/a:some/a:path\",\"list\":[{},{\"key\":\"a\"}]}}}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_ANYDATA, tree->schema->nodetype);
+    assert_string_equal("any", tree->schema->name);
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+
+    lyd_free_all(tree);
+    ly_out_free(out, NULL, 1);
+
+    *state = NULL;
+}
+
+static void
+test_list(void **state)
+{
+    *state = test_list;
+
+    const char *data = "{ \"a:l1\" : [{ \"a\":\"one\",\"b\":\"one\",\"c\":1 }]} ";
+    struct lyd_node *tree, *iter;
+    struct lyd_node_inner *list;
+    struct lyd_node_term *leaf;
+
+    /* check hashes */
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LIST, tree->schema->nodetype);
+    assert_string_equal("l1", tree->schema->name);
+    list = (struct lyd_node_inner*)tree;
+    LY_LIST_FOR(list->child, iter) {
+        assert_int_not_equal(0, iter->hash);
+    }
+    lyd_free_all(tree);
+
+    /* missing keys */
+    data = "{ \"a:l1\": [ {\"c\" : 1, \"b\" : \"b\"}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("List instance is missing its key \"a\". /a:l1[b='b'][c='1']");
+
+    data = "{ \"a:l1\": [ {\"a\" : \"a\"}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("List instance is missing its key \"b\". /a:l1[a='a']");
+
+    data = "{ \"a:l1\": [ {\"b\" : \"b\", \"a\" : \"a\"}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("List instance is missing its key \"c\". /a:l1[a='a'][b='b']");
+
+    /* key duplicate */
+    data = "{ \"a:l1\": [ {\"c\" : 1, \"b\" : \"b\", \"a\" : \"a\", \"c\" : 1}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Duplicate instance of \"c\". /a:l1[a='a'][b='b'][c='1'][c='1']/c");
+
+    /* keys order, in contrast to XML, JSON accepts keys in any order even in strict mode */
+    logbuf_clean();
+    data = "{ \"a:l1\": [ {\"d\" : \"d\", \"a\" : \"a\", \"c\" : 1, \"b\" : \"b\"}]}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LIST, tree->schema->nodetype);
+    assert_string_equal("l1", tree->schema->name);
+    list = (struct lyd_node_inner*)tree;
+    assert_non_null(leaf = (struct lyd_node_term*)list->child);
+    assert_string_equal("a", leaf->schema->name);
+    assert_non_null(leaf = (struct lyd_node_term*)leaf->next);
+    assert_string_equal("b", leaf->schema->name);
+    assert_non_null(leaf = (struct lyd_node_term*)leaf->next);
+    assert_string_equal("c", leaf->schema->name);
+    assert_non_null(leaf = (struct lyd_node_term*)leaf->next);
+    assert_string_equal("d", leaf->schema->name);
+    logbuf_assert("");
+    lyd_free_all(tree);
+
+    /*  */
+    data = "{ \"a:l1\": [ {\"c\" : 1, \"b\" : \"b\", \"a\" : \"a\"}]}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_STRICT, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_LIST, tree->schema->nodetype);
+    assert_string_equal("l1", tree->schema->name);
+    list = (struct lyd_node_inner*)tree;
+    assert_non_null(leaf = (struct lyd_node_term*)list->child);
+    assert_string_equal("a", leaf->schema->name);
+    assert_non_null(leaf = (struct lyd_node_term*)leaf->next);
+    assert_string_equal("b", leaf->schema->name);
+    assert_non_null(leaf = (struct lyd_node_term*)leaf->next);
+    assert_string_equal("c", leaf->schema->name);
+    logbuf_assert("");
+    lyd_free_all(tree);
+
+    data = "{\"a:cp\" : { \"@\" : { \"a:hint\" : 1 }}}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_CONTAINER, tree->schema->nodetype);
+    assert_string_equal("cp", tree->schema->name);
+    assert_non_null(tree->meta);
+    assert_string_equal("hint", tree->meta->name);
+    assert_string_equal("1", tree->meta->value.original);
+    assert_ptr_equal(tree, tree->meta->parent);
+    assert_null(tree->meta->next);
+    lyd_free_all(tree);
+
+    *state = NULL;
+}
+
+static void
+test_container(void **state)
+{
+    *state = test_container;
+
+    const char *data = " {\"a:c\" : {}}";
+    struct lyd_node *tree;
+    struct lyd_node_inner *cont;
+
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_CONTAINER, tree->schema->nodetype);
+    assert_string_equal("c", tree->schema->name);
+    cont = (struct lyd_node_inner*)tree;
+    assert_true(cont->flags & LYD_DEFAULT);
+    lyd_free_all(tree);
+
+    data = "{\"a:cp\" : {}}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_int_equal(LYS_CONTAINER, tree->schema->nodetype);
+    assert_string_equal("cp", tree->schema->name);
+    cont = (struct lyd_node_inner*)tree;
+    assert_false(cont->flags & LYD_DEFAULT);
+    lyd_free_all(tree);
+
+    *state = NULL;
+}
+
+static void
+test_opaq(void **state)
+{
+    *state = test_opaq;
+
+    const char *data;
+    char *str;
+    struct lyd_node *tree;
+
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
+
+    /* invalid value, no flags */
+    data = "{\"a:foo3\":[null]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Invalid empty uint32 value. /a:foo3");
+    assert_null(tree);
+
+    /* opaq flag */
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_OPAQ, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "foo3");
+    assert_string_equal(((struct lyd_node_opaq *)tree)->value, "");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* missing key, no flags */
+    data = "{\"a:l1\":[{\"a\":\"val_a\",\"b\":\"val_b\",\"d\":\"val_d\"}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("List instance is missing its key \"c\". /a:l1[a='val_a'][b='val_b']");
+    assert_null(tree);
+
+    /* opaq flag */
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_OPAQ, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "l1");
+    assert_string_equal(((struct lyd_node_opaq *)tree)->value, "");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* invalid key, no flags */
+    data = "{\"a:l1\":[{\"a\":\"val_a\",\"b\":\"val_b\",\"c\":\"val_c\"}]}";
+    assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Invalid int16 value \"val_c\". /a:l1/c");
+    assert_null(tree);
+
+    /* opaq flag */
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_OPAQ, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "l1");
+    assert_string_equal(((struct lyd_node_opaq *)tree)->value, "");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    data = "{\"a:l1\":[{\"a\":\"val_a\",\"b\":\"val_b\",\"c\":{\"val\":\"val_c\"}}]}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_OPAQ, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "l1");
+    assert_string_equal(((struct lyd_node_opaq *)tree)->value, "");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    data = "{\"a:l1\":[{\"a\":\"val_a\",\"b\":\"val_b\"}]}";
+    assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_JSON, LYD_PARSE_OPAQ, LYD_VALIDATE_PRESENT, &tree));
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "l1");
+    assert_string_equal(((struct lyd_node_opaq *)tree)->value, "");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    ly_out_free(out, NULL, 1);
+
+    *state = NULL;
+}
+
+static void
+test_rpc(void **state)
+{
+    *state = test_rpc;
+
+    const char *data;
+    struct ly_in *in;
+    char *str;
+    struct lyd_node *tree, *op;
+    const struct lyd_node *node;
+
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
+
+    data = "{\"ietf-netconf:rpc\":{\"edit-config\":{"
+              "\"target\":{\"running\":[null]},"
+              "\"config\":{\"a:cp\":{\"z\":[null],\"@z\":{\"ietf-netconf:operation\":\"replace\"}},"
+                          "\"a:l1\":[{\"@\":{\"ietf-netconf:operation\":\"replace\"},\"a\":\"val_a\",\"b\":\"val_b\",\"c\":\"val_c\"}]}"
+            "}}}";
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(data, &in));
+    assert_int_equal(LY_SUCCESS, lyd_parse_rpc(ctx, in, LYD_JSON, &tree, &op));
+    ly_in_free(in, 0);
+
+    assert_non_null(op);
+    assert_string_equal(op->schema->name, "edit-config");
+
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "rpc");
+    /* TODO support generic attributes in JSON ?
+    assert_non_null(((struct lyd_node_opaq *)tree)->attr);
+    */
+    node = lyd_node_children(tree, 0);
+    assert_string_equal(node->schema->name, "edit-config");
+    node = lyd_node_children(node, 0)->next;
+    assert_string_equal(node->schema->name, "config");
+
+    node = ((struct lyd_node_any *)node)->value.tree;
+    assert_non_null(node->schema);
+    assert_string_equal(node->schema->name, "cp");
+    node = lyd_node_children(node, 0);
+    /* z has no value */
+    assert_null(node->schema);
+    assert_string_equal(((struct lyd_node_opaq *)node)->name, "z");
+    node = node->parent->next;
+    /* l1 key c has invalid value so it is at the end */
+    assert_null(node->schema);
+    assert_string_equal(((struct lyd_node_opaq *)node)->name, "l1");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* wrong namespace, element name, whatever... */
+    /* TODO */
+
+    ly_out_free(out, NULL, 1);
+
+    *state = NULL;
+}
+
+static void
+test_action(void **state)
+{
+    *state = test_action;
+
+    const char *data;
+    struct ly_in *in;
+    char *str;
+    struct lyd_node *tree, *op;
+    const struct lyd_node *node;
+
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
+
+    data = "{\"ietf-netconf:rpc\":{\"yang:action\":{\"a:c\":{\"act\":{\"al\":\"value\"}}}}}";
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(data, &in));
+    assert_int_equal(LY_SUCCESS, lyd_parse_rpc(ctx, in, LYD_JSON, &tree, &op));
+    ly_in_free(in, 0);
+
+    assert_non_null(op);
+    assert_string_equal(op->schema->name, "act");
+
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "rpc");
+    assert_null(((struct lyd_node_opaq *)tree)->attr);
+    node = lyd_node_children(tree, 0);
+    assert_null(node->schema);
+    assert_string_equal(((struct lyd_node_opaq *)node)->name, "action");
+    assert_null(((struct lyd_node_opaq *)node)->attr);
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* wrong namespace, element name, whatever... */
+    /* TODO */
+
+    ly_out_free(out, NULL, 1);
+
+    *state = NULL;
+}
+
+static void
+test_notification(void **state)
+{
+    *state = test_notification;
+
+    const char *data;
+    struct ly_in *in;
+    char *str;
+    struct lyd_node *tree, *ntf;
+    const struct lyd_node *node;
+
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
+
+    data = "{\"ietf-restconf:notification\":{\"eventTime\":\"2037-07-08T00:01:00Z\",\"a:c\":{\"n1\":{\"nl\":\"value\"}}}}";
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(data, &in));
+    assert_int_equal(LY_SUCCESS, lyd_parse_notif(ctx, in, LYD_JSON, &tree, &ntf));
+    ly_in_free(in, 0);
+
+    assert_non_null(ntf);
+    assert_string_equal(ntf->schema->name, "n1");
+
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "notification");
+    assert_null(((struct lyd_node_opaq *)tree)->attr);
+    node = lyd_node_children(tree, 0);
+    assert_null(node->schema);
+    assert_string_equal(((struct lyd_node_opaq *)node)->name, "eventTime");
+    assert_string_equal(((struct lyd_node_opaq *)node)->value, "2037-07-08T00:01:00Z");
+    assert_null(((struct lyd_node_opaq *)node)->attr);
+    node = node->next;
+    assert_non_null(node->schema);
+    assert_string_equal(node->schema->name, "c");
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* top-level notif without envelope */
+    data = "{\"a:n2\":{}}";
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(data, &in));
+    assert_int_equal(LY_SUCCESS, lyd_parse_notif(ctx, in, LYD_JSON, &tree, &ntf));
+    ly_in_free(in, 0);
+
+    assert_non_null(ntf);
+    assert_string_equal(ntf->schema->name, "n2");
+
+    assert_non_null(tree);
+    assert_ptr_equal(ntf, tree);
+
+    lyd_print_tree(out, tree, LYD_JSON, 0);
+    assert_string_equal(str, data);
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* wrong namespace, element name, whatever... */
+    /* TODO */
+
+    ly_out_free(out, NULL, 1);
+
+    *state = NULL;
+}
+
+static void
+test_reply(void **state)
+{
+    *state = test_reply;
+
+    const char *data;
+    struct ly_in *in;
+    char *str;
+    struct lyd_node *request, *tree, *op;
+    const struct lyd_node *node;
+
+    struct ly_out *out;
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
+
+    data = "{\"a:c\":{\"act\":{\"al\":\"value\"}}}";
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(data, &in));
+    assert_int_equal(LY_SUCCESS, lyd_parse_rpc(ctx, in, LYD_JSON, &request, NULL));
+    ly_in_free(in, 0);
+
+    data = "{\"ietf-netconf:rpc-reply\":{\"a:al\":25}}";
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(data, &in));
+    assert_int_equal(LY_SUCCESS, lyd_parse_reply(request, in, LYD_JSON, &tree, &op));
+    ly_in_free(in, 0);
+    lyd_free_all(request);
+
+    assert_non_null(op);
+    assert_string_equal(op->schema->name, "act");
+    node = lyd_node_children(op, 0);
+    assert_non_null(node->schema);
+    assert_string_equal(node->schema->name, "al");
+    assert_true(node->schema->flags & LYS_CONFIG_R);
+
+    assert_non_null(tree);
+    assert_null(tree->schema);
+    assert_string_equal(((struct lyd_node_opaq *)tree)->name, "rpc-reply");
+    node = lyd_node_children(tree, 0);
+    assert_non_null(node->schema);
+    assert_string_equal(node->schema->name, "c");
+
+    /* TODO print only rpc-reply node and then output subtree */
+    lyd_print_tree(out, lyd_node_children(op, 0), LYD_JSON, 0);
+    assert_string_equal(str, "{\"a:al\":25}");
+    ly_out_reset(out);
+    lyd_print_tree(out, lyd_node_children(tree, 0), LYD_JSON, 0);
+    assert_string_equal(str, "{\"a:c\":{\"act\":{\"al\":25}}}");
+    ly_out_reset(out);
+    lyd_free_all(tree);
+
+    /* wrong namespace, element name, whatever... */
+    /* TODO */
+
+    ly_out_free(out, NULL, 1);
+
+    *state = NULL;
+}
+
+int main(void)
+{
+    const struct CMUnitTest tests[] = {
+        cmocka_unit_test_setup_teardown(test_leaf, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_leaflist, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_anydata, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_list, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_container, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_opaq, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_rpc, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_action, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_notification, setup, teardown),
+        cmocka_unit_test_setup_teardown(test_reply, setup, teardown),
+    };
+
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}
diff --git a/tests/utests/data/test_parser_xml.c b/tests/utests/data/test_parser_xml.c
index b7a6952..077c8b4 100644
--- a/tests/utests/data/test_parser_xml.c
+++ b/tests/utests/data/test_parser_xml.c
@@ -154,8 +154,8 @@
 
     lyd_free_all(tree);
 
-    /* parse foo2 but make it implicit */
-    data = "<foo2 xmlns=\"urn:tests:a\" xmlns:wd=\"urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults\" wd:default=\"true\">default-val</foo2>";
+    /* parse foo2 but make it implicit, skip metadata xxx from missing schema */
+    data = "<foo2 xmlns=\"urn:tests:a\" xmlns:wd=\"urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults\" wd:default=\"true\" xmlns:x=\"urn:x\" x:xxx=\"false\">default-val</foo2>";
     assert_int_equal(LY_SUCCESS, lyd_parse_data_mem(ctx, data, LYD_XML, 0, LYD_VALIDATE_PRESENT, &tree));
     assert_non_null(tree);
     assert_int_equal(LYS_LEAF, tree->schema->nodetype);
@@ -387,8 +387,8 @@
     /* opaq flag and fail */
     assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, "<a xmlns=\"ns\"><b>x</b><c xml:id=\"D\">1</c></a>", LYD_XML,
                                                    LYD_PARSE_OPAQ, LYD_VALIDATE_PRESENT, &tree));
+    logbuf_assert("Unknown XML prefix \"xml\". Line number 1.");
     assert_null(tree);
-
     ly_out_free(out, NULL, 1);
 
     *state = NULL;
diff --git a/tests/utests/data/test_types.c b/tests/utests/data/test_types.c
index 02ca2cf..cad0808 100644
--- a/tests/utests/data/test_types.c
+++ b/tests/utests/data/test_types.c
@@ -943,10 +943,10 @@
               "<a:inst xmlns:a=\"urn:tests:types\">/a:list2[a:id='a'][a:value='a']/a:id</a:inst>", LY_SUCCESS, "");
 
     /* key-predicate */
-    data = "/types:list2[types:id='a'][types:value='b']/types:id";
+    data = "/types:list2[id='a'][value='b']/id";
     assert_int_equal(LY_ENOTFOUND, lyd_value_validate(s->ctx, (const struct lyd_node_term*)tree->prev->prev, data, strlen(data),
                                                    tree, NULL));
-    logbuf_assert("Invalid instance-identifier \"/types:list2[types:id='a'][types:value='b']/types:id\" value - instance not found. /");
+    logbuf_assert("Invalid instance-identifier \"/types:list2[id='a'][value='b']/id\" value - instance not found. /");
     /* leaf-list-predicate */
     data = "/types:leaflisttarget[.='c']";
     assert_int_equal(LY_ENOTFOUND, lyd_value_validate(s->ctx, (const struct lyd_node_term*)tree->prev->prev, data, strlen(data),
diff --git a/tests/utests/data/test_validation.c b/tests/utests/data/test_validation.c
index f223a6d..309cc71 100644
--- a/tests/utests/data/test_validation.c
+++ b/tests/utests/data/test_validation.c
@@ -1346,7 +1346,7 @@
     "</cont>";
     assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_XML, LYD_PARSE_ONLY | LYD_PARSE_NO_STATE, 0, &tree));
     assert_null(tree);
-    logbuf_assert("Invalid state data node \"cont2\" found. Line number 1.");
+    logbuf_assert("Invalid state data node \"cont2\" found. /h:cont/cont2");
 
     assert_int_equal(LY_EVALID, lyd_parse_data_mem(ctx, data, LYD_XML, 0, LYD_VALIDATE_PRESENT | LYD_VALIDATE_NO_STATE, &tree));
     assert_null(tree);