refactor: Refactor interaction handling and event management

- Updated interactionCreate event to improve error handling and logging.
- Enhanced ready event to ensure client user is available before proceeding.
- Refactored voiceStateUpdate event for better clarity and error handling.
- Adjusted index.ts to improve client initialization and command/event loading.
- Improved Shoukaku event handling and initialization in ShoukakuEvents.ts.
- Enhanced logger utility for better message formatting.
- Updated TypeScript configuration for better compatibility and strictness.
- Created a new botClient type definition for improved type safety.

README.md

@@ -8,6 +8,7 @@ Discord music bot template written in TypeScript using `discord.js` and `shoukak
 - `shoukaku` integration for robust Lavalink audio playback
 - Modular command and event handlers written in TypeScript
 - Basic Docker support (`Dockerfile`, `docker-compose.yml`)
+- Comprehensive test suite with Jest
 
 ## Prerequisites
 
@@ -83,6 +84,51 @@ Discord music bot template written in TypeScript using `discord.js` and `shoukak
     pnpm start # Check package.json for the exact start script (might run compiled JS or use ts-node)
     ```
 
+## Testing
+
+The project includes a comprehensive test suite using Jest. The tests cover commands, events, and utilities.
+
+### Running Tests
+
+```bash
+# Run all tests with coverage report
+pnpm test
+
+# Run tests in watch mode during development
+pnpm test:watch
+
+# Run tests in CI environment
+pnpm test:ci
+```
+
+### Test Structure
+
+```
+tests/
+├── commands/           # Tests for bot commands
+│   ├── join.test.ts
+│   ├── leave.test.ts
+│   ├── ping.test.ts
+│   └── play.test.ts
+├── events/            # Tests for event handlers
+│   ├── interactionCreate.test.ts
+│   ├── ready.test.ts
+│   └── voiceStateUpdate.test.ts
+└── utils/            # Test utilities and mocks
+    ├── setup.ts     # Jest setup and global mocks
+    ├── testUtils.ts # Common test utilities
+    └── types.ts     # TypeScript types for tests
+```
+
+### Coverage Requirements
+
+The project maintains high test coverage requirements:
+
+- Branches: 80%
+- Functions: 80%
+- Lines: 80%
+- Statements: 80%
+
 ## Docker
 
 A `Dockerfile` and `docker-compose.yml` are provided for containerized deployment.
@@ -100,22 +146,20 @@ A `Dockerfile` and `docker-compose.yml` are provided for containerized deploymen
 .
 ├── src/                      # Source code directory
 │   ├── commands/             # Slash command modules (.ts)
-│   ├── events/               # Discord.js and Shoukaku event handlers (.ts)
-│   ├── structures/           # Custom structures or base classes (e.g., Shoukaku event handlers)
-│   ├── utils/                # Utility functions (e.g., logger.ts)
-│   └── index.ts              # Main application entry point
-├── plugins/                  # Lavalink plugins (e.g., youtube-plugin-*.jar)
-├── tests/                    # Test files
-├── .env.example              # Example environment variables
-├── .gitignore
-├── application.yml           # Lavalink server configuration
-├── deploy-commands.ts        # Script to register slash commands
-├── docker-compose.yml        # Docker Compose configuration for bot + Lavalink
-├── Dockerfile                # Dockerfile for building the bot image
-├── LICENSE                   # Project License (GPLv3)
-├── package.json              # Node.js project manifest
-├── tsconfig.json             # TypeScript compiler options
-└── update-plugin.sh          # Script to update Lavalink plugins (example)
+│   ├── events/              # Discord.js and Shoukaku event handlers (.ts)
+│   ├── structures/          # Custom structures or base classes (e.g., Shoukaku event handlers)
+│   └── utils/               # Utility functions (e.g., logger.ts)
+├── tests/                   # Test files (see Testing section)
+├── plugins/                 # Lavalink plugins (e.g., youtube-plugin-*.jar)
+├── .env.example            # Example environment variables
+├── application.yml         # Lavalink server configuration
+├── deploy-commands.ts      # Script to register slash commands
+├── docker-compose.yml      # Docker Compose configuration
+├── Dockerfile             # Dockerfile for building the bot image
+├── jest.config.ts        # Jest test configuration
+├── package.json          # Node.js project manifest
+├── tsconfig.json        # TypeScript compiler options
+└── update-plugin.sh    # Script to update Lavalink plugins
 ```
 
 ## License