DotThrow

DotThrow is a .NET library for automatic exception catching and rule validation

Installation

Download Source Code from Releases.

Nuget Download Link

For installing from nuget, run this command from Package Manager Console

Install-Package DotThrow -Version 1.0.0

Or from .NET CLI

dotnet add package DotThrow --version 1.0.0

Usage

DotThrow offers three features. We can create automatic exception caching through method chaining or we can create validation rules for each type in general or grouped way.

Example 1 (Method Chaining):

string s = "aAaaa";

s.CreateThrower()
    .ThrowIfNullOrWhiteSpace()
    .ThrowIf(s => s.Length > 20, "Length is greater than 20!")
    .ThrowIf(s => s.Length == a.Length, "Both are equal!")
    .ThrowIfNotValidJson()
    .ThrowIfNotValidXml()
    .ThrowIfAllLower();

ICollection<int> vs = new List<int> { 1, 2 };
vs.CreateThrower()
    .ThrowIfEmpty()
    .ThrowIf(x => x.Count > 1, "List has more than one element")
    .ThrowIfCountIsGreaterThan(4)
    .ThrowIfCountIsLessThan(2)
    .ThrowIfCountIsEqualTo(3);

IDictionary<string, int> map = new Dictionary<string, int>
{
    { "x", 1 }
};
map.CreateThrower()
    .ThrowIfEmpty()
    .ThrowIf(x => x.ContainsKey("x"));

HashSet<string> set = new HashSet<string> { "x" };
set.CreateThrower()
    .ThrowIfEmpty()
    .ThrowIf(x => x.Contains("x"));

int b = 10;
b.CreateThrower()
    .ThrowIfEqual(10)
    .ThrowIfGreaterThanOrEqualZero()
    .ThrowIfLessThanOrEqualZero()
    .ThrowIfZero()
    .ThrowIf(x => (x & 5) == 0);

DateTime dateTime = DateTime.ParseExact("26/03/2022", "dd/MM/yyyy", null);
dateTime.CreateThrower()
    .ThrowIfOlderThan(DateTime.ParseExact("11/11/2020", "dd/MM/yyyy", null))
    .ThrowIfAfterThan(DateTime.ParseExact("11/11/2024", "dd/MM/yyyy", null))
    .ThrowIf(x => (DateTime.Now - x).Days > 5, "Day difference is greater than 5!")
    .ThrowIfEquals(DateTime.ParseExact("26/03/2022", "dd/MM/yyyy", null))
    .ThrowIfAfterThanNow()
    .ThrowIfOlderThanNow();

Example 2 (Validation Rules Non Grouped):

Validator<string>.AddRule(str => str.Length < 1, "String length is greater than 2", typeof(InvalidDataException), "String length is less than equal to 2");
Validator<string>.AddRule(str => str.Length < 1, "String length is greater than 3", typeof(InvalidDataException));
Validator<string>.AddRule(str => str.Length > 4, "String length is greater than 4", typeof(InvalidDataException), "String length is less than equal to 4");

string a = "1234";
// This will throw exception whenever test variable break a rule
Validator<string>.Verify(a);

// This will not throw exception but generates report for each rule if test variable breaks it or not
var reports = Validator<string>.VerifyNotThrow(a);
foreach (var report in reports)
{
    Console.WriteLine(report);
}

Example 3 (Validation Rules Grouped):

// Here we are creating a group named "test group 1"
Validator<List<int>>.AddRule(list => list.Count > 3, "List contains more than 3 items", typeof(OverflowException), "List Contains Regular items", "test group 1");
Validator<List<int>>.AddRule(list => list.Count > 5, "List contains more than 5 items", typeof(OverflowException), "List Contains Regular items", "test group 1");

List<int> list = new() { 1, 2, 3, 4, 5, 6 };

// We are passing the group name parameter in the method
Validator<List<int>>.Verify(list, "test group 1");

var reports = Validator<List<int>>.VerifyNotThrow(list, "test group 1");
foreach (var report in reports)
{
    Console.WriteLine(report);
}

Roadmap

Currently this project is in beta version and Method Builder is introduced only for string class. Though API can be extended by creating more extension method of ExceptionThrower struct.

These are the features or improvement currently in development -

1. Method Chaining Extensions for more type (Collections, Primitives.....)
2. Configuration file format for Method Builder and Validation Rule in XML and Json. So that no extra code needed and configuration is portable between projects.
3. File or DB logging of complete stack trace.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT

Contact

Email: shalahuddinshanto@gmail.com