structure FEATURE support for ietf-yang-structure-ext

Only for the structure itself, no augment yet.
diff --git a/tests/utests/extensions/test_structure.c b/tests/utests/extensions/test_structure.c
new file mode 100644
index 0000000..9ceab20
--- /dev/null
+++ b/tests/utests/extensions/test_structure.c
@@ -0,0 +1,192 @@
+/**
+ * @file test_structure.c
+ * @author Michal Vasko <mvasko@cesnet.cz>
+ * @brief unit tests for structure extensions support
+ *
+ * Copyright (c) 2022 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
+ */
+#define _UTEST_MAIN_
+#include "utests.h"
+
+#include "libyang.h"
+
+static void
+test_schema(void **state)
+{
+    struct lys_module *mod;
+    struct lysc_ext_instance *e;
+    char *printed = NULL;
+    const char *data = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure struct {"
+            "  must \"/n2/l\";"
+            "  status deprecated;"
+            "  description desc;"
+            "  reference no-ref;"
+            "  typedef my-type {type string;}"
+            "  grouping my-grp {leaf gl {type my-type;}}"
+            "  grouping my-grp2 {leaf gl-obs {type uint16;}}"
+            "  container n1 {leaf l {config false; type uint32;}}"
+            "  list n2 {leaf l {type leafref {path /n1/l;}}}"
+            "  uses my-grp;"
+            "  uses my-grp2 {status obsolete;}"
+            "}}";
+    const char *info = "module a {\n"
+            "  namespace \"urn:tests:extensions:structure:a\";\n"
+            "  prefix self;\n"
+            "\n"
+            "  ietf-yang-structure-ext:structure \"struct\" {\n"
+            "    must \"/n2/l\";\n"
+            "    status deprecated;\n"
+            "    description\n"
+            "      \"desc\";\n"
+            "    reference\n"
+            "      \"no-ref\";\n"
+            "    container n1 {\n"
+            "      status deprecated;\n"
+            "      leaf l {\n"
+            "        type uint32;\n"
+            "        status deprecated;\n"
+            "      }\n"
+            "    }\n"
+            "    list n2 {\n"
+            "      min-elements 0;\n"
+            "      max-elements 4294967295;\n"
+            "      ordered-by user;\n"
+            "      status deprecated;\n"
+            "      leaf l {\n"
+            "        type leafref {\n"
+            "          path \"/n1/l\";\n"
+            "          require-instance true;\n"
+            "          type uint32;\n"
+            "        }\n"
+            "        status deprecated;\n"
+            "      }\n"
+            "    }\n"
+            "    leaf gl {\n"
+            "      type string;\n"
+            "      status deprecated;\n"
+            "    }\n"
+            "    leaf gl-obs {\n"
+            "      type uint16;\n"
+            "      status obsolete;\n"
+            "    }\n"
+            "  }\n"
+            "}\n";
+
+    /* valid data */
+    assert_int_equal(LY_SUCCESS, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, &mod));
+    assert_non_null(e = mod->compiled->exts);
+    assert_int_equal(LY_ARRAY_COUNT(mod->compiled->exts), 1);
+    assert_int_equal(LY_SUCCESS, lys_print_mem(&printed, mod, LYS_OUT_YANG_COMPILED, 0));
+    assert_string_equal(printed, info);
+    free(printed);
+
+    /* no substatements */
+    data = "module b {yang-version 1.1; namespace urn:tests:extensions:structure:b; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure struct;}";
+    info = "module b {\n"
+            "  namespace \"urn:tests:extensions:structure:b\";\n"
+            "  prefix self;\n"
+            "\n"
+            "  ietf-yang-structure-ext:structure \"struct\";\n"
+            "}\n";
+    assert_int_equal(LY_SUCCESS, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, &mod));
+    assert_non_null(e = mod->compiled->exts);
+    assert_int_equal(LY_ARRAY_COUNT(mod->compiled->exts), 1);
+    assert_int_equal(LY_SUCCESS, lys_print_mem(&printed, mod, LYS_OUT_YANG_COMPILED, 0));
+    assert_string_equal(printed, info);
+    free(printed);
+}
+
+static void
+test_schema_invalid(void **state)
+{
+    const char *data;
+
+    data = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure struct {import yang;}}";
+    assert_int_equal(LY_EVALID, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, NULL));
+    CHECK_LOG_CTX("Invalid keyword \"import\" as a child of \"sx:structure struct\" extension instance.",
+            "/a:{extension='sx:structure'}/struct");
+
+    data = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "container b { sx:structure struct { container x { leaf x {type string;}}}}}";
+    assert_int_equal(LY_EVALID, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, NULL));
+    CHECK_LOG_CTX("Extension plugin \"libyang 2 - structure, version 1\": "
+            "Extension sx:structure must not be used as a non top-level statement in \"container\" statement.",
+            "/a:b/{extension='sx:structure'}/struct");
+
+    data = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure { container x { leaf x {type string;}}}}";
+    assert_int_equal(LY_EVALID, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, NULL));
+    CHECK_LOG_CTX("Extension instance \"sx:structure\" misses argument element \"name\".",
+            "/a:{extension='sx:structure'}");
+
+    data = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure struct { container x { leaf x {type string;}}}"
+            "sx:structure struct { container y { leaf y {type string;}}}}";
+    assert_int_equal(LY_EVALID, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, NULL));
+    CHECK_LOG_CTX("Extension plugin \"libyang 2 - structure, version 1\": "
+            "Extension sx:structure is instantiated multiple times.",
+            "/a:{extension='sx:structure'}/struct");
+
+    data = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure struct { container x { leaf x {type string;}}}"
+            "choice struct { container y { leaf y {type string;}}}}";
+    assert_int_equal(LY_EVALID, lys_parse_mem(UTEST_LYCTX, data, LYS_IN_YANG, NULL));
+    CHECK_LOG_CTX("Extension plugin \"libyang 2 - structure, version 1\": "
+            "Extension sx:structure collides with a choice with the same identifier.",
+            "/a:{extension='sx:structure'}/struct");
+}
+
+static void
+test_parse(void **state)
+{
+    struct lys_module *mod;
+    struct lysc_ext_instance *e;
+    struct lyd_node *tree = NULL;
+    const char *schema = "module a {yang-version 1.1; namespace urn:tests:extensions:structure:a; prefix self;"
+            "import ietf-yang-structure-ext {prefix sx;}"
+            "sx:structure struct { container x { leaf x { type string;}}}}";
+    const char *xml = "<x xmlns=\"urn:tests:extensions:structure:a\"><x>test</x></x>";
+    const char *json = "{\"a:x\":{\"x\":\"test\"}}";
+
+    assert_int_equal(LY_SUCCESS, lys_parse_mem(UTEST_LYCTX, schema, LYS_IN_YANG, &mod));
+    assert_non_null(e = mod->compiled->exts);
+
+    assert_int_equal(LY_SUCCESS, ly_in_new_memory(xml, &UTEST_IN));
+    assert_int_equal(LY_SUCCESS, lyd_parse_ext_data(e, NULL, UTEST_IN, LYD_XML, 0, LYD_VALIDATE_PRESENT, &tree));
+    CHECK_LYD_STRING_PARAM(tree, xml, LYD_XML, LYD_PRINT_SHRINK | LYD_PRINT_WITHSIBLINGS);
+    lyd_free_all(tree);
+
+    ly_in_memory(UTEST_IN, json);
+    assert_int_equal(LY_SUCCESS, lyd_parse_ext_data(e, NULL, UTEST_IN, LYD_JSON, 0, LYD_VALIDATE_PRESENT, &tree));
+    CHECK_LYD_STRING_PARAM(tree, json, LYD_JSON, LYD_PRINT_SHRINK | LYD_PRINT_WITHSIBLINGS);
+
+    lyd_free_all(tree);
+}
+
+int
+main(void)
+{
+    const struct CMUnitTest tests[] = {
+        UTEST(test_schema),
+        UTEST(test_schema_invalid),
+        UTEST(test_parse),
+    };
+
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}