Currency Converter CLI

A CLI application for converting currencies using historical exchange rates.

Features

• Convert currency amounts based on historical exchange rates.
• Cache exchange rates to minimize API calls.
• Continuously validate user inputs.
• Save successful conversions to a JSON file.
• Terminate the application by typing 'END' at any input prompt.

Prerequisites

• Node.js (>= 12.x)
• npm (>= 6.x)

Installation

1. Clone the repository:

   git clone https://github.com/dstoneva/currency-convertor.git
   cd currency-convertor

2. Install the dependencies:

   npm install

3. Create a config.json file in the root of the project and add your Fast Forex API key:

   config.json:

   {
     "api_key": "your_api_key_here"
   }

Scripts

• npm run build: Compile the TypeScript code.
• npm run lint: Run ESLint to check for linting errors.

Usage

Start the application by running:

npx ts-node src/CurrencyConversion.ts YYYY-MM-DD

Replace YYYY-MM-DD with the desired date.

Note: The historical data is limited to 14 days during the trial period of the Fast Forex API.

The application will prompt you for the following inputs:

1. Amount: The amount of money to convert (e.g., 10.23).
2. Base Currency: The ISO 4217 currency code of the base currency (e.g., USD).
3. Target Currency: The ISO 4217 currency code of the target currency (e.g., EUR).

You can terminate the application at any prompt by typing END.

Example

npx ts-node src/CurrencyConversion.ts 2024-06-01

# Amount
10.23

# Base Currency
USD

# Target Currency
EUR

# Output
10.23 USD is 9.52 EUR

Project structure

• api/: Contains the module for fetching exchange rates from the Fast Forex API.
• cache/: Contains the module for caching exchange rates.
• handlers/: Contains modules for handling application tasks (e.g., file operations, input validation, currency conversion).
• types/: Contains TypeScript type definitions.
• validation/: Contains input validation functions.
• index.ts: Exports modules for easier imports in other parts of the application.
• CurrencyConversion.ts: The main application script.

License

This project is licensed under the ISC License. See the LICENSE file for details.