branch-2.1: [regression-test](Variant) add escaped chars cases #52657 (#52699)

Cherry-picked from #52657

Co-authored-by: lihangyu <lihangyu@selectdb.com>

regression-test/data/variant_p0/escaped_chars.out

@@ -0,0 +1,31 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !select --
+1	{"a":123,"b":"test with escape \\" characters"}
+2	{"a":456,"b":"another test with escape \\\\ characters"}
+3	{"a":789,"b":"test with single quote ' characters"}
+4	{"a":101112,"b":"test with newline \\n characters"}
+5	{"a":131415,"b":"test with tab \\t characters"}
+6	{"a":161718,"b":"test with backslash \\b characters"}
+
+-- !select --
+test with escape " characters
+another test with escape \\ characters
+test with single quote ' characters
+test with newline \n characters
+test with tab \	 characters
+test with backslash  characters
+
+-- !select --
+test with escape " characters
+another test with escape \\ characters
+test with single quote ' characters
+test with newline \n characters
+test with tab \	 characters
+test with backslash  characters
+
+-- !select --
+1	{"c_json":{"a":"a\\nb"}}	{"c_json":{"quote":"\\"Helvetica tofu try-hard gluten-free gentrify leggings.\\" - Remington Trantow"}}	{"c_json":{"quote":"\\"Helvetica tofu try-hard gluten-free gentrify leggings.\\" - Remington Trantow"}}	{"c_json":{"a":"a\\nb"}}
+
+-- !select --
+{"a":"a\\nb"}	{"a":"a\\nb"}
+

regression-test/suites/variant_p0/escaped_chars.groovy

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+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("regression_test_variant_escaped_chars", "p0"){
+    def tableName = "variant_escape_chars"
+
+    sql """ DROP TABLE IF EXISTS variant_escape_chars """
+
+    sql """
+        CREATE TABLE IF NOT EXISTS variant_escape_chars (
+            `id` INT,
+            `description` VARIANT 
+        ) ENGINE=OLAP
+        DUPLICATE KEY(`id`)
+        COMMENT 'This is a test table with escape characters in description'
+        DISTRIBUTED BY HASH(`id`) BUCKETS 1
+        PROPERTIES (
+            "replication_num" = "1"
+        );
+    """
+
+    sql """
+        INSERT INTO variant_escape_chars VALUES
+        (1, '{"a" : 123, "b" : "test with escape \\\\" characters"}'),
+        (2, '{"a" : 456, "b" : "another test with escape \\\\\\\\ characters"}'),
+        (3, '{"a" : 789, "b" : "test with single quote \\\' characters"}'),
+        (4, '{"a" : 101112, "b" : "test with newline \\\\n characters"}'),
+        (5, '{"a" : 131415, "b" : "test with tab \\\\t characters"}'),
+        (6, '{"a" : 161718, "b" : "test with backslash \\\\b characters"}');
+    """
+
+    // test json value with escaped characters
+    qt_select """ SELECT * FROM variant_escape_chars ORDER BY id """
+    qt_select """ SELECT description['b'] FROM variant_escape_chars ORDER BY id """
+    qt_select """ SELECT CAST(description['b'] AS TEXT) FROM variant_escape_chars ORDER BY id """
+
+    sql """
+        drop table if exists t01;
+        create table t01(id int, b json, c json, d variant, e variant) properties ("replication_num" = "1");
+        insert into t01 values (1, '{"c_json":{"a":"a\\\\nb"}}', '{"c_json": {"quote":"\\\\"Helvetica tofu try-hard gluten-free gentrify leggings.\\\\" - Remington Trantow"}}', '{"c_json": {"quote":"\\\\"Helvetica tofu try-hard gluten-free gentrify leggings.\\\\" - Remington Trantow"}}', '{"c_json":{"a":"a\\\\nb"}}');
+    """
+    qt_select """ SELECT * FROM t01 """
+    qt_select """select json_extract(b, "\$.c_json"), e["c_json"] from t01;"""
+
+    // test json keys with escaped characters, FIXED in 3.1.0
+    // sql "truncate table variant_escape_chars"
+    // sql """
+    //     INSERT INTO variant_escape_chars VALUES
+    //     (1, '{"test with escape \\\\" characters" : 123}'),
+    //     (2, '{"another test with escape \\\\\\\\ characters" : 123}'),
+    //     (3, '{"test with single quote \\\' characters" : 123}'),
+    //     (4, '{"test with newline \\\\n characters":123}'),
+    //     (5, '{"test with tab \\\\t characters" : 123}'),
+    //     (6, '{"test with backslash \\\\b characters" : 123}');
+    // """
+    // qt_select """ SELECT * FROM variant_escape_chars ORDER BY id """
+}