xunit: define codefixes for ExceptionAsserts

[Meir017]

The asserts defined in https://github.com/xunit/assert.xunit/blob/main/ExceptionAsserts.cs

• Exception Throws(Type exceptionType, Action testCode);
• Exception Throws(Type exceptionType, Func<object?> testCode);
• T Throws<T>(Action testCode) where T : Exception;
• T Throws<T>(Func<object?> testCode) where T : Exception;
• T Throws<T>(string? paramName, Action testCode) where T : ArgumentException;
• T Throws<T>(string? paramName, Func<object?> testCode);

---

• T ThrowsAny<T>(Action testCode) where T : Exception;
• T ThrowsAny<T>(Func<object?> testCode) where T : Exception;

---

• async Task<T> ThrowsAnyAsync<T>(Func<Task> testCode) where T : Exception;

---

• async Task<Exception> ThrowsAsync(Type exceptionType, Func<Task> testCode);
• async Task<T> ThrowsAsync<T>(Func<Task> testCode) where T : Exception;
• async Task<T> ThrowsAsync<T>(string? paramName, string paramName, Func<Task> testCode) where T : ArgumentException;

[Meir017]

The simple assertions methods:

public T Throws<T>(Action testCode) where T : Exception
{
    Assert.NotNull(Assert.Throws<T>(testCode));
    testCode.Should().ThrowExactly<T>().Which.Should().NotBeNull();

    Assert.Throws<T>(testCode);
    testCode.Should().ThrowExactly<T>();

    return default;
}

public async Task<T> ThrowsAsync<T>(Func<Task> testCode) where T : Exception
{
    Assert.NotNull(await Assert.ThrowsAsync<T>(testCode));
    (await testCode.Should().ThrowExactlyAsync<T>()).Which.Should().NotBeNull();

    await Assert.ThrowsAsync<T>(testCode);
    await testCode.Should().ThrowExactlyAsync<T>();

    return default;
}

public T ThrowsAny<T>(Action testCode) where T : Exception
{   
    Assert.NotNull(Assert.ThrowsAny<T>(testCode));
    testCode.Should().Throw<T>().Which.Should().NotBeNull();

    Assert.ThrowsAny<T>(testCode);
    testCode.Should().Throw<T>();

    

    return default;
}

public async Task<T> ThrowsAnyAsync<T>(Func<Task> testCode) where T : Exception
{
    Assert.NotNull(await Assert.ThrowsAnyAsync<T>(testCode));
    (await testCode.Should().ThrowAsync<T>()).Which.Should().NotBeNull();

    await Assert.ThrowsAnyAsync<T>(testCode);
    await testCode.Should().ThrowAsync<T>();

    return default;
}

[Meir017]

not sure about the methods:

public static T Throws<T>(string paramName, Action testCode) where T : ArgumentException {}
public static T Throws<T>(string paramName, Func<object> testCode) where T : ArgumentException {}
public static async Task<T> ThrowsAsync<T>(string paramName, Func<Task> testCode) where T : ArgumentException {}
public static async ValueTask<T> ThrowsAsync<T>(string paramName, Func<ValueTask> testCode) where T : ArgumentException {}

maybe something like this:

public async Task<T> ThrowsAnyAsync<T>(Func<Task> testCode) where T : Exception
{
    Assert.NotNull(await Assert.ThrowsAnyAsync<T>(testCode));
    (await testCode.Should().ThrowAsync<T>()).Which.Should().NotBeNull();

    await Assert.ThrowsAnyAsync<T>(testCode);
    await testCode.Should().ThrowAsync<T>();

    return default;
}

public static async Task<T> ThrowsAsync<T>(string paramName, Func<Task> testCode) where T : ArgumentException
{
    Assert.NotNull(await Assert.ThrowsAsync<T>(paramName, testCode));
    (await testCode.Should().ThrowExactlyAsync<T>().WithParameterName(paramName)).Which.Should().NotBeNull();

    await Assert.ThrowsAsync<T>(paramName, testCode);
    await testCode.Should().ThrowExactlyAsync<T>().WithParameterName(paramName);

    return default;
}