Etymon.Result 1.2.0

Etymon.Result

Etymon.Result is a lightweight C# library for handling success and failure outcomes in a clean and structured way using the Result pattern.

🚀 Features

• Unified success and failure model
• Supports both Result<T> and Result (for void)
• Clean functional style: Match, Deconstruct, implicit conversion
• Supports enum-based error codes using ResultCode

📦 Installation

dotnet add package Etymon.Result

✅ How to Use

Step 1: Change your service return type

Change this:

Task<Model> GetItem(int id);

To:

Task<Result<Model>> GetItem(int id);

Step 2: Implement the service method

public async Task<Result<Model>> GetItem(int id)
{
    var data = await _db.Items.FirstOrDefaultAsync(i => i.Id == id);

    if (data == null)
    {
        return new Error("DataNotFound", "Item you're looking for is not available.");
        // OR (recommended from v1.2+)
        // return Result<Model>.Failure(ResultCode.NotFound, "Item you're looking for is not available.");
    }

    return data; // Implicitly converted to Result<Model>.Success(data)
}

✅ Tip: You can use Result.Success(data) explicitly, or just return the data directly.

Step 3: Controller usage

[Route("get-item")]
[HttpGet]
public async Task<IActionResult> GetItemById(int id)
{
    var result = await _service.GetItem(id);

    if (!result.IsSuccess)
    {
        if (result.Error?.Code == "DataNotFound")
            return NotFound(result);
        else
            return BadRequest(result);
    }

    return Ok(result);
}

⚠️ If you use BadRequest(result.Error.Message) you'll lose the full error structure (see Step 4 for sample outputs).

Step 4: Output Examples

✅ Success response:

{
  "data": {
    "id": 1,
    "itemName": "some item",
    "isActive": false
  },
  "error": null,
  "isSuccess": true
}

❌ Failure response:

{
  "data": null,
  "error": {
    "code": "DataNotFound",
    "message": "Item you're looking for is not available."
  },
  "isSuccess": false
}

🔧 Update in v1.1.2 – Result without return value (void-like)

Prior to v1.1.2, Result<T> was required. Now, you can return just Result for operations that don’t return a value:

public async Task<Result> SaveItem(Item model)
{
    using var trans = await _db.Database.BeginTransactionAsync();

    try
    {
        var obj = await _db.Items.FirstOrDefaultAsync(x => x.ItemId == model.ItemId) ?? new Item();

        obj.Title = model.Title;

        _db.Entry(obj).State = obj.ItemId > 0 ? EntityState.Modified : EntityState.Added;

        await _db.SaveChangesAsync();
        await trans.CommitAsync();

        return Result.Success();
    }
    catch (Exception ex)
    {
        await trans.RollbackAsync();
        return Result.Failure(new Error("UnrecognisedError", "Something went wrong!"));
    }
}

🆕 Update in v1.2.0 – Enum-based Error Support

In version 1.2.0, we've added support for ResultCode enum for standardized error handling.

You can now create errors like this:

return Result<Model>.Failure(ResultCode.NotFound, "Item not found.");

This allows you to use consistent and meaningful codes instead of free-form strings, making controller mapping and API responses cleaner.

🧱 Built-in ResultCode Enum

public enum ResultCode
{
    Success,
    NotFound,
    ValidationError,
    Unauthorized,
    Conflict,
    InternalError
}

The Error class now supports both string-based and enum-based codes.

✨ Extension Package: Etymon.Result.Extensions

For cleaner controller code and automatic HTTP status mapping, install the optional extensions package:

dotnet add package Etymon.Result.Extensions

Then use the ToActionResult() helper in your controller:

using Etymon.Result.Extensions;

[HttpGet("{id}")]
public async Task<IActionResult> GetItem(int id)
{
    var result = await _service.GetItem(id);
    return result.ToActionResult();
}

This maps ResultCode to appropriate HTTP responses like 200 OK, 404 NotFound, 400 BadRequest, etc., so you don't have to write repetitive logic.

🔄 Coming Soon (Planned Features)

• Result middleware for automatic API response wrapping
• Built-in integration with FluentValidation
• Localization support in Error

❤️ Contribute / Feedback

Feel free to open issues or pull requests for enhancements or bug reports.