String Calculator

Overview

This project implements a simple String Calculator following the Test-Driven Development (TDD) approach. The calculator can add numbers provided in a string format with various delimiters and handle edge cases such as empty strings and negative numbers.

Features

• Add numbers from a comma-separated string.
• Handle any number of inputs.
• Support new lines as delimiters.
• Support custom delimiters.
• Raise exceptions for negative numbers, listing all negative values provided.

Requirements

• Ruby (version 2.7 or later)
• RSpec for testing

Getting Started

1. Clone the repository:

   git clone https://github.com/abhinandan2012/string_calculator.git
   cd string_calculator

2. Install reuired gems:

   bundle install
   

Running Tests

1. To run the tests, execute:

   bundle exec rspec
   

Implementation details

The StringCalculator class has a single class method add which takes a string of numbers and returns their sum. The method follows these rules:

• An empty string returns 0.
• A single number returns that number.
• Multiple numbers separated by commas or new lines are summed up.
• Custom delimiters can be defined at the beginning of the string using the format //[delimiter]\n[numbers].
• If negative numbers are included, an exception is raised listing all negative numbers provided.

TDD Process

This project was developed using the Test-Driven Development (TDD) methodology. The process involved writing a test for each feature, implementing the simplest solution to pass the test, and refactoring as necessary.