diff --git a/tests/unit/config_handling/test_settings_loader.py b/tests/unit/config_handling/test_settings_loader.py
new file mode 100644
index 0000000..f4dd966
--- /dev/null
+++ b/tests/unit/config_handling/test_settings_loader.py
@@ -0,0 +1,708 @@
+"""
+Unit tests for SettingsLoader class
+"""
+
+import configparser
+from pathlib import Path
+from unittest.mock import Mock
+import pytest
+from pytest import CaptureFixture
+from corelibs.config_handling.settings_loader import SettingsLoader
+from corelibs.logging_handling.log import Log
+
+
+class TestSettingsLoaderInit:
+    """Test cases for SettingsLoader initialization"""
+
+    def test_init_with_valid_config_file(self, tmp_path: Path):
+        """Test initialization with a valid config file"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[Section]\nkey=value\n")
+
+        loader = SettingsLoader(
+            args={},
+            config_file=config_file,
+            log=None,
+            always_print=False
+        )
+
+        assert loader.args == {}
+        assert loader.config_file == config_file
+        assert loader.log is None
+        assert loader.always_print is False
+        assert loader.config_parser is not None
+        assert isinstance(loader.config_parser, configparser.ConfigParser)
+
+    def test_init_with_missing_config_file(self, tmp_path: Path):
+        """Test initialization with missing config file"""
+        config_file = tmp_path / "missing.ini"
+
+        loader = SettingsLoader(
+            args={},
+            config_file=config_file,
+            log=None,
+            always_print=False
+        )
+
+        assert loader.config_parser is None
+
+    def test_init_with_invalid_config_folder(self):
+        """Test initialization with invalid config folder path"""
+        config_file = Path("/nonexistent/path/test.ini")
+
+        with pytest.raises(ValueError, match="Cannot find the config folder"):
+            SettingsLoader(
+                args={},
+                config_file=config_file,
+                log=None,
+                always_print=False
+            )
+
+    def test_init_with_log(self, tmp_path: Path):
+        """Test initialization with Log object"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[Section]\nkey=value\n")
+        mock_log = Mock(spec=Log)
+
+        loader = SettingsLoader(
+            args={"test": "value"},
+            config_file=config_file,
+            log=mock_log,
+            always_print=True
+        )
+
+        assert loader.log == mock_log
+        assert loader.always_print is True
+
+
+class TestLoadSettings:
+    """Test cases for load_settings method"""
+
+    def test_load_settings_basic(self, tmp_path: Path):
+        """Test loading basic settings without validation"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nkey1=value1\nkey2=value2\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings("TestSection")
+
+        assert result == {"key1": "value1", "key2": "value2"}
+
+    def test_load_settings_with_missing_section(self, tmp_path: Path):
+        """Test loading settings with missing section"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[OtherSection]\nkey=value\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Cannot read \\[MissingSection\\]"):
+            loader.load_settings("MissingSection")
+
+    def test_load_settings_allow_not_exist(self, tmp_path: Path):
+        """Test loading settings with allow_not_exist flag"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[OtherSection]\nkey=value\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings("MissingSection", allow_not_exist=True)
+
+        assert result == {}
+
+    def test_load_settings_mandatory_field_present(self, tmp_path: Path):
+        """Test mandatory field validation when field is present"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nrequired_field=value\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"required_field": ["mandatory:yes"]}
+        )
+
+        assert result["required_field"] == "value"
+
+    def test_load_settings_mandatory_field_missing(self, tmp_path: Path):
+        """Test mandatory field validation when field is missing"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nother_field=value\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"required_field": ["mandatory:yes"]}
+            )
+
+    def test_load_settings_mandatory_field_empty(self, tmp_path: Path):
+        """Test mandatory field validation when field is empty"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nrequired_field=\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"required_field": ["mandatory:yes"]}
+            )
+
+    def test_load_settings_with_split(self, tmp_path: Path):
+        """Test splitting values into lists"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nlist_field=a,b,c,d\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"list_field": ["split:,"]}
+        )
+
+        assert result["list_field"] == ["a", "b", "c", "d"]
+
+    def test_load_settings_with_custom_split_char(self, tmp_path: Path):
+        """Test splitting with custom delimiter"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nlist_field=a|b|c|d\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"list_field": ["split:|"]}
+        )
+
+        assert result["list_field"] == ["a", "b", "c", "d"]
+
+    def test_load_settings_split_removes_spaces(self, tmp_path: Path):
+        """Test that split removes spaces from values"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nlist_field=a, b , c , d\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"list_field": ["split:,"]}
+        )
+
+        assert result["list_field"] == ["a", "b", "c", "d"]
+
+    def test_load_settings_empty_split_char_fallback(self, tmp_path: Path, capsys: CaptureFixture[str]):
+        """Test fallback to default split char when empty"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nlist_field=a,b,c\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"list_field": ["split:"]}
+        )
+
+        assert result["list_field"] == ["a", "b", "c"]
+        captured = capsys.readouterr()
+        assert "fallback to:" in captured.out
+
+    def test_load_settings_convert_to_int(self, tmp_path: Path):
+        """Test converting values to int"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nnumber=123\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"number": ["convert:int"]}
+        )
+
+        assert result["number"] == 123
+        assert isinstance(result["number"], int)
+
+    def test_load_settings_convert_to_float(self, tmp_path: Path):
+        """Test converting values to float"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nnumber=123.45\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"number": ["convert:float"]}
+        )
+
+        assert result["number"] == 123.45
+        assert isinstance(result["number"], float)
+
+    def test_load_settings_convert_to_bool_true(self, tmp_path: Path):
+        """Test converting values to boolean True"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nflag1=true\nflag2=True\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"flag1": ["convert:bool"], "flag2": ["convert:bool"]}
+        )
+
+        assert result["flag1"] is True
+        assert result["flag2"] is True
+
+    def test_load_settings_convert_to_bool_false(self, tmp_path: Path):
+        """Test converting values to boolean False"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nflag1=false\nflag2=False\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"flag1": ["convert:bool"], "flag2": ["convert:bool"]}
+        )
+
+        assert result["flag1"] is False
+        assert result["flag2"] is False
+
+    def test_load_settings_convert_invalid_type(self, tmp_path: Path):
+        """Test converting with invalid type raises error"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=test\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="convert type is invalid"):
+            loader.load_settings(
+                "TestSection",
+                {"value": ["convert:invalid"]}
+            )
+
+    def test_load_settings_empty_set_to_none(self, tmp_path: Path):
+        """Test setting empty values to None"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nother=value\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"field": ["empty:"]}
+        )
+
+        assert result["field"] is None
+
+    def test_load_settings_empty_set_to_custom_value(self, tmp_path: Path):
+        """Test setting empty values to custom value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nother=value\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"field": ["empty:default"]}
+        )
+
+        assert result["field"] == "default"
+
+    def test_load_settings_matching_valid(self, tmp_path: Path):
+        """Test matching validation with valid value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nmode=production\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"mode": ["matching:development|staging|production"]}
+        )
+
+        assert result["mode"] == "production"
+
+    def test_load_settings_matching_invalid(self, tmp_path: Path):
+        """Test matching validation with invalid value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nmode=invalid\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"mode": ["matching:development|staging|production"]}
+            )
+
+    def test_load_settings_in_valid(self, tmp_path: Path):
+        """Test 'in' validation with valid value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nallowed=a,b,c\nvalue=b\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {
+                "allowed": ["split:,"],
+                "value": ["in:allowed"]
+            }
+        )
+
+        assert result["value"] == "b"
+
+    def test_load_settings_in_invalid(self, tmp_path: Path):
+        """Test 'in' validation with invalid value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nallowed=a,b,c\nvalue=d\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {
+                    "allowed": ["split:,"],
+                    "value": ["in:allowed"]
+                }
+            )
+
+    def test_load_settings_in_missing_target(self, tmp_path: Path):
+        """Test 'in' validation with missing target"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=a\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"value": ["in:missing_target"]}
+            )
+
+    def test_load_settings_length_exact(self, tmp_path: Path):
+        """Test length validation with exact match"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=test\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"value": ["length:4"]}
+        )
+
+        assert result["value"] == "test"
+
+    def test_load_settings_length_exact_invalid(self, tmp_path: Path):
+        """Test length validation with exact match failure"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=test\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"value": ["length:5"]}
+            )
+
+    def test_load_settings_length_range(self, tmp_path: Path):
+        """Test length validation with range"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=testing\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"value": ["length:5-10"]}
+        )
+
+        assert result["value"] == "testing"
+
+    def test_load_settings_length_min_only(self, tmp_path: Path):
+        """Test length validation with minimum only"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=testing\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"value": ["length:5-"]}
+        )
+
+        assert result["value"] == "testing"
+
+    def test_load_settings_length_max_only(self, tmp_path: Path):
+        """Test length validation with maximum only"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=test\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"value": ["length:-10"]}
+        )
+
+        assert result["value"] == "test"
+
+    def test_load_settings_range_valid(self, tmp_path: Path):
+        """Test range validation with valid value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nnumber=25\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"number": ["range:10-50"]}
+        )
+
+        assert result["number"] == "25"
+
+    def test_load_settings_range_invalid(self, tmp_path: Path):
+        """Test range validation with invalid value"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nnumber=100\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"number": ["range:10-50"]}
+            )
+
+    def test_load_settings_check_int_valid(self, tmp_path: Path):
+        """Test check:int with valid integer"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nnumber=12345\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"number": ["check:int"]}
+        )
+
+        assert result["number"] == "12345"
+
+    def test_load_settings_check_int_cleanup(self, tmp_path: Path):
+        """Test check:int with cleanup"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nnumber=12a34b5\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"number": ["check:int"]}
+        )
+
+        assert result["number"] == "12345"
+
+    def test_load_settings_check_email_valid(self, tmp_path: Path):
+        """Test check:string.email.basic with valid email"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nemail=test@example.com\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"email": ["check:string.email.basic"]}
+        )
+
+        assert result["email"] == "test@example.com"
+
+    def test_load_settings_check_email_invalid(self, tmp_path: Path):
+        """Test check:string.email.basic with invalid email"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nemail=not-an-email\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Missing or incorrect settings data"):
+            loader.load_settings(
+                "TestSection",
+                {"email": ["check:string.email.basic"]}
+            )
+
+    def test_load_settings_args_override(self, tmp_path: Path, capsys: CaptureFixture[str]):
+        """Test command line arguments override config values"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=config_value\n")
+
+        loader = SettingsLoader(
+            args={"value": "arg_value"},
+            config_file=config_file
+        )
+        result = loader.load_settings(
+            "TestSection",
+            {"value": []}
+        )
+
+        assert result["value"] == "arg_value"
+        captured = capsys.readouterr()
+        assert "Command line option override" in captured.out
+
+    def test_load_settings_no_config_file_with_args(self, tmp_path: Path):
+        """Test loading settings without config file but with mandatory args"""
+        config_file = tmp_path / "missing.ini"
+
+        loader = SettingsLoader(
+            args={"required": "value"},
+            config_file=config_file
+        )
+        result = loader.load_settings(
+            "TestSection",
+            {"required": ["mandatory:yes"]}
+        )
+
+        assert result["required"] == "value"
+
+    def test_load_settings_no_config_file_missing_args(self, tmp_path: Path):
+        """Test loading settings without config file and missing args"""
+        config_file = tmp_path / "missing.ini"
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Cannot find file"):
+            loader.load_settings(
+                "TestSection",
+                {"required": ["mandatory:yes"]}
+            )
+
+    def test_load_settings_check_list_with_split(self, tmp_path: Path):
+        """Test check validation with list values"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nlist=abc,def,ghi\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"list": ["split:,", "check:string.alphanumeric"]}
+        )
+
+        assert result["list"] == ["abc", "def", "ghi"]
+
+    def test_load_settings_check_list_cleanup(self, tmp_path: Path):
+        """Test check validation cleans up list values"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nlist=ab-c,de_f,gh!i\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "TestSection",
+            {"list": ["split:,", "check:string.alphanumeric"]}
+        )
+
+        assert result["list"] == ["abc", "def", "ghi"]
+
+    def test_load_settings_invalid_check_type(self, tmp_path: Path):
+        """Test with invalid check type"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text("[TestSection]\nvalue=test\n")
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+
+        with pytest.raises(ValueError, match="Cannot get SettingsLoaderCheck.CHECK_SETTINGS"):
+            loader.load_settings(
+                "TestSection",
+                {"value": ["check:invalid.check.type"]}
+            )
+
+
+class TestComplexScenarios:
+    """Test cases for complex real-world scenarios"""
+
+    def test_complex_validation_scenario(self, tmp_path: Path):
+        """Test complex scenario with multiple validations"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text(
+            "[Production]\n"
+            "environment=production\n"
+            "allowed_envs=development,staging,production\n"
+            "port=8080\n"
+            "host=example.com\n"
+            "timeout=30\n"
+            "debug=false\n"
+            "features=auth,logging,monitoring\n"
+        )
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "Production",
+            {
+                "environment": [
+                    "mandatory:yes",
+                    "matching:development|staging|production",
+                    "in:allowed_envs"
+                ],
+                "allowed_envs": ["split:,"],
+                "port": ["mandatory:yes", "convert:int", "range:1-65535"],
+                "host": ["mandatory:yes"],
+                "timeout": ["convert:int", "range:1-"],
+                "debug": ["convert:bool"],
+                "features": ["split:,", "check:string.alphanumeric"],
+            }
+        )
+
+        assert result["environment"] == "production"
+        assert result["allowed_envs"] == ["development", "staging", "production"]
+        assert result["port"] == 8080
+        assert isinstance(result["port"], int)
+        assert result["host"] == "example.com"
+        assert result["timeout"] == 30
+        assert result["debug"] is False
+        assert result["features"] == ["auth", "logging", "monitoring"]
+
+    def test_email_list_validation(self, tmp_path: Path):
+        """Test email list with validation"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text(
+            "[EmailConfig]\n"
+            "emails=test@example.com,admin@domain.org,user+tag@site.co.uk\n"
+        )
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "EmailConfig",
+            {"emails": ["split:,", "mandatory:yes", "check:string.email.basic"]}
+        )
+
+        assert len(result["emails"]) == 3
+        assert "test@example.com" in result["emails"]
+
+    def test_mixed_args_and_config(self, tmp_path: Path):
+        """Test mixing command line args and config file"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text(
+            "[Settings]\n"
+            "value1=config_value1\n"
+            "value2=config_value2\n"
+        )
+
+        loader = SettingsLoader(
+            args={"value1": "arg_value1"},
+            config_file=config_file
+        )
+        result = loader.load_settings(
+            "Settings",
+            {"value1": [], "value2": []}
+        )
+
+        assert result["value1"] == "arg_value1"  # Overridden by arg
+        assert result["value2"] == "config_value2"  # From config
+
+    def test_multiple_check_types(self, tmp_path: Path):
+        """Test multiple different check types"""
+        config_file = tmp_path / "test.ini"
+        config_file.write_text(
+            "[Checks]\n"
+            "numbers=123,456,789\n"
+            "alphas=abc,def,ghi\n"
+            "emails=test@example.com\n"
+            "date=2025-01-15\n"
+        )
+
+        loader = SettingsLoader(args={}, config_file=config_file)
+        result = loader.load_settings(
+            "Checks",
+            {
+                "numbers": ["split:,", "check:int"],
+                "alphas": ["split:,", "check:string.alphanumeric"],
+                "emails": ["check:string.email.basic"],
+                "date": ["check:string.date"],
+            }
+        )
+
+        assert result["numbers"] == ["123", "456", "789"]
+        assert result["alphas"] == ["abc", "def", "ghi"]
+        assert result["emails"] == "test@example.com"
+        assert result["date"] == "2025-01-15"
+
+
+# __END__