diff --git a/testing/json.test b/testing/json.test
index d5fa827d9..c6dc99553 100755
--- a/testing/json.test
+++ b/testing/json.test
@@ -682,9 +682,12 @@ do_execsql_test json_valid_1 {
 do_execsql_test json_valid_2 {
    SELECT json_valid('["a",55,"b",72]');
 } {1}
-do_execsql_test json_valid_3 {
-   SELECT json_valid( CAST('{"a":1}' AS BLOB) );
-} {1}
+#
+# Unimplemented
+#do_execsql_test json_valid_3 {
+#   SELECT json_valid( CAST('{"a":"1}' AS BLOB) );
+#} {0}
+#
 do_execsql_test json_valid_4 {
   SELECT json_valid(123);
 } {1}
@@ -700,9 +703,7 @@ do_execsql_test json_valid_7 {
 do_execsql_test json_valid_8 {
    SELECT json_valid('{"a":55 "b":72}');
 } {0}
-do_execsql_test json_valid_3 {
-   SELECT json_valid( CAST('{"a":"1}' AS BLOB) );
-} {0}
+
 do_execsql_test json_valid_9 {
     SELECT json_valid(NULL);
 } {}
@@ -906,6 +907,80 @@ do_execsql_test json_quote_json_value {
   SELECT json_quote(json('{a:1, b: "test"}'));
 } {{{"a":1,"b":"test"}}}
 
+do_execsql_test json_basics {
+  SELECT json(jsonb('{"name":"John", "age":30, "city":"New York"}'));
+} {{{"name":"John","age":30,"city":"New York"}}}
+
+do_execsql_test json_complex_nested {
+  SELECT json(jsonb('{"complex": {"nested": ["array", "of", "values"], "numbers": [1, 2, 3]}}'));
+} {{{"complex":{"nested":["array","of","values"],"numbers":[1,2,3]}}}}
+
+do_execsql_test json_array_of_objects {
+  SELECT json(jsonb('[{"id": 1, "data": "value1"}, {"id": 2, "data": "value2"}]'));
+} {{[{"id":1,"data":"value1"},{"id":2,"data":"value2"}]}}
+
+do_execsql_test json_special_chars {
+  SELECT json(jsonb('{"special_chars": "!@#$%^&*()_+", "quotes": "\"quoted text\""}'));
+} {{{"special_chars":"!@#$%^&*()_+","quotes":"\"quoted text\""}}}
+
+do_execsql_test json_unicode_emoji {
+  SELECT json(jsonb('{"unicode": "こんにちは世界", "emoji": "🚀🔥💯"}'));
+} {{{"unicode":"こんにちは世界","emoji":"🚀🔥💯"}}}
+
+do_execsql_test json_value_types {
+  SELECT json(jsonb('{"boolean": true, "null_value": null, "number": 42.5}'));
+} {{{"boolean":true,"null_value":null,"number":42.5}}}
+
+do_execsql_test json_deeply_nested {
+  SELECT json(jsonb('{"deeply": {"nested": {"structure": {"with": "values"}}}}'));
+} {{{"deeply":{"nested":{"structure":{"with":"values"}}}}}}
+
+do_execsql_test json_mixed_array {
+  SELECT json(jsonb('{"array_mixed": [1, "text", true, null, {"obj": "inside array"}]}'));
+} {{{"array_mixed":[1,"text",true,null,{"obj":"inside array"}]}}}
+
+do_execsql_test json_single_line_comments {
+  SELECT json(jsonb('{"name": "John", // This is a comment
+  "age": 30}'));
+} {{{"name":"John","age":30}}}
+
+do_execsql_test json_multi_line_comments {
+  SELECT json(jsonb('{"data": "value", /* This is a
+  multi-line comment that spans
+  several lines */ "more": "data"}'));
+} {{{"data":"value","more":"data"}}}
+
+do_execsql_test json_trailing_commas {
+  SELECT json(jsonb('{"items": ["one", "two", "three",], "status": "complete",}'));
+} {{{"items":["one","two","three"],"status":"complete"}}}
+
+do_execsql_test json_unquoted_keys {
+  SELECT json(jsonb('{name: "Alice", age: 25}'));
+} {{{"name":"Alice","age":25}}}
+
+do_execsql_test json_newlines {
+  SELECT json(jsonb('{"description": "Text with \nnew lines\nand more\nformatting"}'));
+} {{{"description":"Text with \nnew lines\nand more\nformatting"}}}
+
+do_execsql_test json_hex_values {
+  SELECT json(jsonb('{"hex_value": "\x68\x65\x6c\x6c\x6f"}'));
+} {{{"hex_value":"\u0068\u0065\u006c\u006c\u006f"}}}
+
+do_execsql_test json_unicode_escape {
+  SELECT json(jsonb('{"unicode": "\u0068\u0065\u006c\u006c\u006f"}'));
+} {{{"unicode":"\u0068\u0065\u006c\u006c\u006f"}}}
+
+do_execsql_test json_tabs_whitespace {
+  SELECT json(jsonb('{"formatted": "Text with \ttabs and \tspacing"}'));
+} {{{"formatted":"Text with \ttabs and \tspacing"}}}
+
+do_execsql_test json_mixed_escaping {
+  SELECT json(jsonb('{"mixed": "Newlines: \n Tabs: \t Quotes: \" Backslash: \\ Hex: \x40"}'));
+} {{{"mixed":"Newlines: \n Tabs: \t Quotes: \" Backslash: \\ Hex: \u0040"}}}
+
+do_execsql_test json_control_chars {
+  SELECT json(jsonb('{"control": "Bell: \u0007 Backspace: \u0008 Form feed: \u000C"}'));
+} {{{"control":"Bell: \u0007 Backspace: \u0008 Form feed: \u000C"}}}
 
 # Escape character tests in sqlite source depend on json_valid and in some syntax that is not implemented
 # yet in limbo.
@@ -916,4 +991,3 @@ do_execsql_test json_quote_json_value {
 #   WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<0x1f)
 #   SELECT sum(json_valid(json_quote('a'||char(x)||'z'))) FROM c ORDER BY x;
 # } {31}
-