call-methods-with-autofixture.cs

//_fixture.Call(patient, "UpdateDemographics");

//call a method with values from autofixture.
public static T Call<T>(this T component, Fixture fixture, string methodName) where T : class
{
    var methodInfo = typeof(T).GetMethod(methodName);

    var fixtureCreateMethod = typeof(SpecimenFactory)
        .GetMethods()
        .Where(m => m.Name == "Create" && m.IsGenericMethodDefinition)
        .Select(m => new
        {
            Method = m,
            Params = m.GetParameters(),
        })
        .Where(a => a.Params.Length == 1 && a.Params[0].ParameterType == typeof(ISpecimenBuilder))
        .Select(a => a.Method)
        .Single();

    var stringFixtureCreateMethod = typeof(SpecimenFactory)
        .GetMethods()
        .Where(m => m.Name == "Create" && m.IsGenericMethodDefinition)
        .Select(m => new
        {
            Method = m,
            Params = m.GetParameters(),
        })
        .Where(a => a.Params.Length == 2 && a.Params[0].ParameterType == typeof(ISpecimenBuilder))
        .Select(a => a.Method)
        .Single();

    var parameters = methodInfo
        .GetParameters()
        .Select(x => x.ParameterType == typeof(string)
            ? stringFixtureCreateMethod.MakeGenericMethod(x.ParameterType).Invoke(null, new object[] {fixture, x.Name}) //this one sticks the param name on the start of the created string
            : fixtureCreateMethod.MakeGenericMethod(x.ParameterType).Invoke(null, new object[] {fixture}))
        .ToArray();

    methodInfo.Invoke(component, parameters);

    return component;
}