XUnit3Helper 0.0.5-alpha

XUnit3Helper

A utility library for convenient work with xUnit v3. Designed to speed up writing parameterized tests and to simplify preparing mocks in DI containers.

Key features

• Attribute JsonFileDataAttribute — load data for Theory from a JSON file (multiple formats, sections).
• Attribute CustomAutoDataAttribute — ready-made configuration for AutoFixture + AutoMoq (including ConfigureMembers and recursion behavior).
• Extension MockExtension.AddMocks — bulk registration of Moq mocks into IServiceCollection.
• Helper generator GenerateTestDataExtension and model TestData — support for deserializing JSON into parameter sets up to 15 arguments.
• Supported targets: net8.0, net9.0, net10.0.

Usage

1. JsonFileDataAttribute

• Constructor: JsonFileDataAttribute(string filePath, bool simpleTypeJson = false, string? sectionKey = null)
• Behavior:
  • Checks that the file exists.
  • If sectionKey is specified, extracts the corresponding JSON section (top-level key).
  • Supports two JSON formats:
    • "Complex" — an array of objects with fields P1, P2, ... (matches the TestData models).
    • "Simple" (simpleTypeJson = true) — an array of arrays or an array of strings/numbers, where each element of an inner array corresponds to a test parameter.
  • Limitation: up to 15 parameters (the test-case generation logic is implemented for 1..15 parameters).
• Examples: Complex data format (recommended):

[
    {
        "P1": 1,
        "P2": "a",
        "P3": true
    },
    {
        "P1": 2,
        "P2": "b",
        "P3": false
    }
]

Simple types format (simpleTypeJson = true):

[
    [1, "a", true],
    [2, "b", false]
]

Usage in tests:

    [Theory, JsonFileData("testdata.json")]
    public void MyTest(int a, string b, bool flag)
    {
        // ...
    }

    [Theory, JsonFileData("simple.json", simpleTypeJson: true)]
    public void SimpleTest(int a, string b)
    {
        // ...
    }

    [Theory, JsonFileData("config.json", sectionKey: "cases")]
    public void SectionedTest(int x, int y)
    {
        // ...
    }

2. CustomAutoDataAttribute

• A simplified attribute for use with AutoFixture + AutoMoq.
• Configuration:
  • Adds AutoMoqCustomization with ConfigureMembers = true.
  • Removes ThrowingRecursionBehavior and adds OmitOnRecursionBehavior to safely generate object graphs.
• Example:

    [Theory, CustomAutoData]
    public void AutoFixtureTest(MyService sut, int n)
    {
        Assert.NotNull(sut);
    }

3. MockExtension.AddMocks

• An extension for IServiceCollection: for each provided Type it registers:
  • Mock<T> as scoped,
  • T (mock.Object) as scoped.
• Removes existing registrations for the type before adding the mock.
• Example:

    var services = new ServiceCollection();
    services.AddMocks(typeof(IMyService), typeof(IOtherService));

or with generics (implemented via reflection for each type in the code).

License

• MIT