Calculator Challenge

This project is a calculator engine implemented in C# that supports a variety of mathematical operations with flexible delimiters. It includes comprehensive unit tests to ensure all functionalities are thoroughly tested.

Features

The calculator provides the following features:

• Supports multiple numbers: Initially, the calculator supports up to 2 numbers using a comma delimiter. However, this limit can be removed by invoking RemoveNumberLimit(), allowing the calculator to handle more than 2 numbers.
• Supports newline (\n) as an additional delimiter: Numbers can be separated by either a comma or newline character.
• Ignores numbers greater than 1000: Any number larger than 1000 is excluded from the sum.
• Custom single-character delimiter support: Allows users to define their own single-character delimiters.
• Custom multi-character delimiter support: Supports multi-character delimiters as well.
• Multiple custom delimiters: Enables the use of multiple custom delimiters simultaneously.
• Handles invalid numbers gracefully: Any invalid numbers are treated as 0 and do not break the operation.
• Throws exception for negative numbers: If negative numbers are included in the input, an exception is thrown, listing all negative numbers in the exception message.

Requirements

• .NET Core SDK (v6.0 or later)
• NUnit for testing
• NUnit3TestAdapter
• Microsoft.NET.Test.Sdk

Running the Application

Clone the Repository:

git clone https://github.com/ericdotnet/CalculatorTask.git
cd calculatortask

Build the Project:

dotnet build

Running the Unit Tests

The project uses NUnit for unit testing. Ensure the following NuGet packages are installed:

• NUnit
• NUnit3TestAdapter
• Microsoft.NET.Test.Sdk

Running Tests via Command Line:

To execute the tests, run the following command:

dotnet test

Running Tests in Visual Studio:

1. Open the solution in Visual Studio.
2. Navigate to the Test Explorer (View -> Test Explorer).
3. Click on Run All to execute all tests.

Unit Test Cases

Empty String Returns Zero:

• Input: ""
• Expected Result: "0"

Single Number Returns the Same:

• Input: "20"
• Expected Result: "20"

Remove Number Limit Allows More Than Two Numbers:

• Input: "1,2,3,4,5"
• Expected Result: "15" (after calling RemoveNumberLimit())

Newline Delimiter Returns Sum:

• Input: "1\n2,3"
• Expected Result: "6"

Numbers Greater Than 1000 Are Ignored:

• Input: "2,1001,6"
• Expected Result: "8"

Custom Single-Character Delimiter Returns Sum:

• Input: "//#\n2#5"
• Expected Result: "7"

Custom Multi-Character Delimiter Returns Sum:

• Input: "//[***]\n11***22***33"
• Expected Result: "66"

Multiple Custom Delimiters Return Sum:

• Input: "//[*][!!][r9r]\n11r9r22!!33*44"
• Expected Result: "110"

Invalid Numbers Are Ignored:

• Input: "5,tytyt"
• Expected Result: "5"

Negative Numbers Throw Exception:

• Input: "1,-2,3"
• Expected Result: Throws an exception with message "Negative numbers not allowed: -2"

Multiple Negative Numbers Throw Exception with All Negatives Listed:

• Input: "1,-2,-3,4"
• Expected Result: Throws an exception with message "Negative numbers not allowed: -2, -3"