making sure the issue comes from GDUnit addon folder

addons/gdUnit4/src/fuzzers/StringFuzzer.gd

@@ -0,0 +1,112 @@
+## A fuzzer that generates random strings with configurable length and character sets.[br]
+##
+## It supports custom character sets defined by patterns or ranges,
+## making it ideal for testing input validation, text processing, parsers, or any
+## code that handles string data.[br]
+##
+## The fuzzer uses a pattern syntax to define allowed characters:[br]
+## - Single characters: [code]abc[/code] allows 'a', 'b', 'c'[br]
+## - Ranges: [code]a-z[/code] allows lowercase letters[br]
+## - Special patterns: [code]\\w[/code] (word chars), [code]\\p{L}[/code] (letters), [code]\\p{N}[/code] (numbers)[br]
+##
+## [b]Usage example:[/b]
+## [codeblock]
+## # Test with alphanumeric strings
+## func test_username(fuzzer := StringFuzzer.new(3, 20, "a-zA-Z0-9"), _fuzzer_iterations := 100):
+##     var username _= fuzzer.next_value()
+##     assert_bool(validate_username(username)).is_true()
+##
+## # Test with special characters
+## func test_password(fuzzer := StringFuzzer.new(8, 32, "a-zA-Z0-9!@#$%"), _fuzzer_iterations := 100) -> void:
+##     var password := fuzzer.next_value()
+##     assert_str(password).has_length(8, Comparator.GREATER_EQUAL).has_length(32, Comparator.LESS_EQUAL)
+## [/codeblock]
+class_name StringFuzzer
+extends Fuzzer
+
+## Default character set pattern including word characters, letters, numbers, and common symbols.[br]
+## Includes: word characters (\\w), Unicode letters (\\p{L}), Unicode numbers (\\p{N}),
+## and the characters: +, -, _, '
+const DEFAULT_CHARSET = "\\w\\p{L}\\p{N}+-_'"
+
+## Minimum length for generated strings (inclusive).
+var _min_length: int
+## Maximum length for generated strings (inclusive).
+var _max_length: int
+## Array of character codes that can be used in generated strings.
+var _charset: PackedInt32Array
+
+
+func _init(min_length: int, max_length: int, pattern: String = DEFAULT_CHARSET) -> void:
+	_min_length = min_length
+	_max_length = max_length + 1 # +1 for inclusive
+	assert(not null or not pattern.is_empty())
+	assert(_min_length > 0 and _min_length < _max_length)
+	_charset = _extract_charset(pattern)
+
+
+## Generates a random string based on configured parameters.[br]
+##
+## Creates a string with random length between [member _min_length] and
+## [member _max_length], using only characters from the configured charset.
+## Each character is selected randomly and independently.[br]
+##
+## [b]Example:[/b]
+## [codeblock]
+## var fuzzer = StringFuzzer.new(5, 10, "ABC")
+## for i in range(5):
+##     var str = fuzzer.next_value()
+##     print("Generated: ", str)
+##     # Possible outputs: "ABCAB", "BCAABCA", "CCCBAA", etc.
+##     assert(str.length() >= 5 and str.length() <= 10)
+##     for c in str:
+##         assert(c in ["A", "B", "C"])
+## [/codeblock]
+##
+## @returns A random string matching the configured constraints.
+func next_value() -> String:
+	var value := PackedInt32Array()
+	var max_char := len(_charset)
+	var length: int = max(_min_length, randi() % _max_length)
+	for i in length:
+		@warning_ignore("return_value_discarded")
+		value.append(_charset[randi() % max_char])
+	return value.to_byte_array().get_string_from_utf32()
+
+
+static func _extract_charset(pattern: String) -> PackedInt32Array:
+	var reg := RegEx.new()
+	if reg.compile(pattern) != OK:
+		push_error("Invalid pattern to generate Strings! Use e.g  '\\w\\p{L}\\p{N}+-_'")
+		return PackedInt32Array()
+
+	var charset := PackedInt32Array()
+	var char_before := -1
+	var index := 0
+	while index < pattern.length():
+		var char_current := pattern.unicode_at(index)
+		# - range token at first or last pos?
+		if char_current == 45 and (index == 0 or index == pattern.length()-1):
+			charset.append(char_current)
+			index += 1
+			continue
+		index += 1
+		# range starts
+		if char_current == 45 and char_before != -1:
+			var char_next := pattern.unicode_at(index)
+			var characters := _build_chars(char_before, char_next)
+			for character in characters:
+				charset.append(character)
+			char_before = -1
+			index += 1
+			continue
+		char_before = char_current
+		charset.append(char_current)
+	return charset
+
+
+static func _build_chars(from: int, to: int) -> PackedInt32Array:
+	var characters := PackedInt32Array()
+	for character in range(from+1, to+1):
+		characters.append(character)
+	return characters