fluentassertions2shouldly

FluentAssertions2Shouldly

This library was developed using Cursor, an AI-powered code editor.

All code, all tests and all documentation was written by the AI, no code was written by me.

The AI is not perfect, it is like a very newbie developer. It needed a lot of coaching, and it didn't remember what it was told. On the bright side, it never complained, but just tried to do what it was told, and I could do other stuff while it was wading through its own errors, trying to fix them.

A library that provides a FluentAssertions-style syntax while using Shouldly under the hood. This is perfect for:

• Projects migrating from FluentAssertions to Shouldly
• Teams who prefer FluentAssertions' syntax but want to use Shouldly's features
• Maintaining consistent test style across mixed codebases

Requirements

• .NET 6 or higher (required for global using statements and file-scoped namespaces)

Installation

dotnet add package FluentAssertions2Shouldly

Usage

The library provides a familiar FluentAssertions-style syntax:

// String assertions
string text = "Hello";
text.Should().Be("Hello");
text.Should().StartWith("He");
text.Should().Contain("ell");

// Numeric assertions
int number = 42;
number.Should().Be(42);
number.Should().BeGreaterThan(40);
number.Should().BeInRange(40, 45);

// Collection assertions
var list = new[] { 1, 2, 3 };
list.Should().HaveCount(3);
list.Should().Contain(2);
list.Should().BeInAscendingOrder();

// Exception assertions
Action action = () => throw new Exception();
action.Should().Throw<Exception>();

While using Shouldly under the hood:

// What you write
text.Should().Be("Hello");

// What actually runs
text.ShouldBe("Hello");

Features

Core Assertions

• String assertions
• Numeric assertions
• Boolean assertions
• Collection assertions
• Exception assertions
• DateTime assertions
• Dictionary assertions

Specialized Assertions

• File assertions
• Async/Task assertions
• Approximate equality assertions
• Enum assertions
• Property change assertions
• Custom assertions

Documentation

• Getting Started
• Advanced Features
• Migration Guide
• API Reference

Migration

The library makes it easy to migrate from FluentAssertions to Shouldly gradually:

• Replace FluentAssertions package with FluentAssertions2Shouldly
• Tests continue to work with the same syntax
• Optionally migrate to native Shouldly syntax over time

Example:

// Original FluentAssertions code
using FluentAssertions;
value.Should().Be(expected);

// Step 1: Switch to FluentAssertions2Shouldly
using FluentAssertions2Shouldly;
value.Should().Be(expected);

// Step 2 (Optional): Native Shouldly
using Shouldly;
value.ShouldBe(expected);

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the MIT License - see the LICENSE file for details.