https://github.com/choc13/sharpequalstester

Test your C# classes' Equals and GetHashCode implementations with ease
https://github.com/choc13/sharpequalstester

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Test your C# classes' Equals and GetHashCode implementations with ease

• Host: GitHub
• URL: https://github.com/choc13/sharpequalstester
• Owner: Choc13
• License: mit
• Created: 2015-12-06T19:56:22.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-12-08T20:40:35.000Z (over 9 years ago)
• Last Synced: 2024-11-26T01:47:24.614Z (5 months ago)
• Language: C#
• Homepage:
• Size: 21.5 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# SharpEqualsTester

[![Build Status](https://travis-ci.org/Choc13/SharpEqualsTester.svg?branch=master)](https://travis-ci.org/Choc13/SharpEqualsTester)

## What Does It Do?

Helps you quickly test the `Equals` and `GetHashCode` implementations of your classes.

It checks your class meets the following conditions:

1. Comparing against itself returns `true`.

2. Comparing against `null` returns `false`.

3. Comparing to an instance of an incompatible class returns `false`.

4. Comparing two instances with the same data returns `true`.

5. Comparing two instances with different data returns `false`.

6. Comparing the hashcode of two instances with the same data return `true`.

7. Comparing the hashcode of two instances with different data returns `false`.

If any one of the above is not met when `Test()` is called it will throw an appropriate exception indicating which condition was not met and by which object(s).

## How Do I Use It?

1. Install via [NuGet](https://www.nuget.org/packages/SharpEqualsTester/)

2. Write a test like so:

```csharp

    // This example using XUnit, so it will fail if the tester throws

    // In other testing frameworks you may need do something like Assert.DoesNotThrow(() => tester.Test());

    [Fact]

    public void ShouldPassIfEqualsAndHashcodePerfectlyImplemented()

    {

        // Create groups of objects by varying all constructor parameters

        // Create a couple of instances in each group with the same data

        var object1A = new MyClass("one", 1);

        var object1B = new MyClass("one", 1);

        var object2A = new MyClass("two", 1);

        var object2B = new MyClass("two", 1);

        var object3A = new MyClass("one", 2);

        var object3B = new MyClass("one", 2);

        

        // Build and run the EqualsTester

        new EqualsTester()

            .AddEqualityGroup(object1A, object1B)

            .AddEqualityGroup(object2A, object2B)

            .AddEqualityGroup(object3A, object3B)

            .Test();

    }

```

## Some Tips

1. `public EqualsTester AddEqualityGroup(params T[] items)` implements the builder pattern so calls can be chained. It also accepts any number of `T` so the entire group, no matter how large, can be passed in a single call.

2. It's generally not a useful test to add the same instance multiple times to a single equality group as the tester tests each object against itself anyway. Every object added to a group should be a new instance with the same data as other instances in the group.