fix(launch): Added parameter

doc/tests/ConfigManager.md

@@ -0,0 +1,79 @@
+## Unit Tests
+
+Unit tests for `ConfigManager` are implemented in `src/g2_2025_grade_calculator_pkg/test/ConfigManager.test.cpp` using Google Test and ROS2 test utilities. The tests use temporary TOML files to validate configuration loading and parsing functionality.
+
+### Test Cases
+
+#### 1. ConstructorTest
+
+**Description:** Verifies that ConfigManager can be created with a ROS2 logger without crashing.
+
+- **Test Action:** Create ConfigManager instance with ROS2 logger
+- **Expected Result:** Instance created successfully without exceptions
+
+#### 2. LoadValidConfigTest
+
+**Description:** Tests loading of valid TOML configuration files with proper parsing.
+
+- **Test Action:**
+  - Create temporary TOML file with valid configuration
+  - Call `load_config()` with file path
+- **Expected Result:**
+  - Returns `true`
+  - `is_loaded()` returns `true`
+
+#### 3. LoadInvalidFileTest
+
+**Description:** Tests error handling when attempting to load non-existent configuration files.
+
+- **Test Action:** Call `load_config()` with non-existent file path
+- **Expected Result:**
+  - Returns `false`
+  - `is_loaded()` returns `false`
+
+#### 4. DatabaseConfigParsingTest
+
+**Description:** Tests complete database configuration parsing with all parameters.
+
+- **Test Configuration:**
+  ```toml
+  [database]
+  host = "test_host"
+  port = 1234
+  dbname = "test_db"
+  user = "test_user"
+  password = "test_password"
+  timeout = 60
+  ssl = true
+
+  [database.pool]
+  min_connections = 2
+  max_connections = 20
+  ```
+- **Expected Result:** All configuration values parsed correctly with proper types
+
+#### 5. DatabaseConfigWithoutPoolTest
+
+**Description:** Tests default values when optional pool section is missing from configuration.
+
+- **Test Configuration:**
+  ```toml
+  [database]
+  host = "localhost"
+  port = 5432
+  dbname = "grades"
+  user = "postgres"
+  password = "postgres"
+  ```
+- **Expected Result:**
+  - Main database config parsed correctly
+  - Default pool values: `min_connections = 1`, `max_connections = 10`
+
+#### 6. GetConfigWithoutLoadingTest
+
+**Description:** Tests behavior when attempting to access configuration before loading any file.
+
+- **Test Action:** Call `get_database_config()` without loading configuration
+- **Expected Result:**
+  - Returns `std::nullopt`
+  - `is_loaded()` returns `false`