Pavas.Patterns.Result 1.0.4

Result Design Pattern In .NET

Description

The Result design pattern is a technique used to handle the outcomes of operations that can either succeed or fail. This pattern is widely adopted in functional programming and has gained popularity in C# for its effectiveness in managing errors and ensuring safe, predictable code flow.

Basic Usage

The Result pattern encapsulates the result of an operation, which can either be successful or contain an error. Below are the common methods used with the Result pattern:

Creating a Result

• Failure result: Use Result.Failure(error) to represent a failed operation.
• Success result: Use Result.Success() to represent a successful operation without a value.
• Success result with value: Use Result.Success(value) to represent a successful operation that returns a value.

Example

Result.Success();

Result.Success("Operation completed successfully");

new Error {
    Code = "Unespected",
    Name = "Unespected Error",
    Description = "A Unespected Error Has Been Ocurred",
    Extensions = { ["Key"] = "Value" }
};

ErrorFactory.CreateSystemError(
    "Error", 
    "OperationFailed", 
    "An error occurred"
);

ErrorFactory.CreateHttpError(
    StatusCodes.InternalServerError,
    "OperationFailed",
    "An error occurred"
);

Result.Failure(Error);

Matching on Result

result.Match(
    onSuccess: () => "Operation succeeded",
    onFailure: error => $"Operation failed: {error.Message}"
);

result.Match(
    onSuccess: value => $"Operation succeeded, result: {value}",
    onFailure: error => $"Operation failed: {error.Message}"
);

Benefits

• Clear Error Handling: Distinguishes between successful and failed operations, ensuring that error handling is explicit and predictable.
• Immutable Results: Once created, a Result object cannot be altered, making it safe to pass around in your codebase.
• Functional Programming Influence: Encourages a functional approach to handling outcomes, improving code readability and maintainability.

Conclusion

The Result design pattern is a powerful tool for managing outcomes in C# applications, making your code more robust and easier to maintain. By encapsulating success and failure cases, it enforces a clear structure for handling different operation outcomes, leading to more reliable and bug-free code.