Banking Application

This project is a banking application where users can deposit and withdraw money from their bank account. It supports viewing past transactions and ensures no withdrawal occurs if the balance is insufficient.

Screens

Screen_Recording_20250203_173041_TerminalApplication.mp4

Features

• Deposit and Withdraw: Users can deposit and withdraw money from their accounts. Withdrawals are blocked if the balance is insufficient.
• Transaction History: Users can view their past transactions.
• Balance Update: The balance is automatically updated when a transaction is made (deposit or withdrawal).
• Error Handling: Informative messages are shown when errors occur, such as insufficient funds.

Architecture

• MVVM Architecture: The application follows the MVVM (Model-View-ViewModel) pattern to separate concerns and improve testability.
• Room Database: Used for local storage of transaction records. A trigger is used to update the account balance upon each transaction.
• Compose UI: The UI is built using Jetpack Compose for a modern, declarative approach.
• Hilt for Dependency Injection: Used for injecting dependencies in a clean and modular way.

Refactoring Strategy

1. Modularization: The project is organized to separate core functionality (such as data and domain logic) from feature-specific code within the app module. This approach enhances testability and maintainability.
2. UI Tests: Focused on implementing UI tests to ensure the integrity of the UI and prevent regressions during refactoring.
3. Sealed Classes for Navigation: Refactored the navigation setup to use sealed classes instead of hardcoded strings, improving type safety and maintainability.
4. Transaction History Feature: Introduced a feature to view past transactions. The feature leverages Room for persistent storage and displays the history in a clean, scrollable list.

Setup Instructions

1. Clone the Repository:

   git clone [email protected]:swarnsingh/code-challenge-android-mobile.git
   cd <project_directory>
   

2. Install Dependencies:

   ./gradlew build
   

3. Run the Application: The app can be launched on an emulator or a physical device.

Testing Strategy

• Unit Tests: Unit tests have been written to verify the correctness of business logic, such as deposit/withdrawal calculations.
• UI Tests: UI tests were added to ensure that the user interface behaves as expected. This includes tests for the deposit/withdraw buttons, transaction history display, and error handling.
• Regression Testing: UI tests ensure that no regressions are introduced during refactoring.

Assumptions

• The API for fetching transactions is not yet available, so transactions are handled locally using Room.
• The database schema for transactions and balances was set up with triggers to update the balance when a transaction is performed (deposit or withdrawal).

Improvements Deferred

• Network Layer: The app currently uses Room for local storage. Future improvements could include implementing a network layer to sync data with a backend.
• Advanced Error Handling: While basic error handling is implemented, more sophisticated error handling strategies can be considered.

Contributions

Feel free to open issues or submit pull requests for improvements!