using Moq;

// Assumptions:

public interface IFoo
{
    Bar Bar { get; set; }
    string Name { get; set; }
    int Value { get; set; }
    bool DoSomething(string value);
    bool DoSomething(int number, string value);
    Task<bool> DoSomethingAsync();
    string DoSomethingStringy(string value);
    bool TryParse(string value, out string outputValue);
    bool Submit(ref Bar bar);
    int GetCount();
    bool Add(int value);
}

public class Bar 
{
    public virtual Baz Baz { get; set; }
    public virtual bool Submit() { return false; }
}

public class Baz
{
    public virtual string Name { get; set; }
}

var mock = new Mock<IFoo>();
mock.Setup(foo => foo.DoSomething("ping")).Returns(true);


// out arguments
var outString = "ack";
// TryParse will return true, and the out argument will return "ack", lazy evaluated
mock.Setup(foo => foo.TryParse("ping", out outString)).Returns(true);


// ref arguments
var instance = new Bar();
// Only matches if the ref argument to the invocation is the same instance
mock.Setup(foo => foo.Submit(ref instance)).Returns(true);


// access invocation arguments when returning a value
mock.Setup(x => x.DoSomethingStringy(It.IsAny<string>()))
		.Returns((string s) => s.ToLower());
// Multiple parameters overloads available


// throwing when invoked with specific parameters
mock.Setup(foo => foo.DoSomething("reset")).Throws<InvalidOperationException>();
mock.Setup(foo => foo.DoSomething("")).Throws(new ArgumentException("command"));


// lazy evaluating return value
var count = 1;
mock.Setup(foo => foo.GetCount()).Returns(() => count);


// async methods (see below for more about async):
mock.Setup(foo => foo.DoSomethingAsync().Result).Returns(true);

// any value
mock.Setup(foo => foo.DoSomething(It.IsAny<string>())).Returns(true);


// any value passed in a `ref` parameter (requires Moq 4.8 or later):
mock.Setup(foo => foo.Submit(ref It.Ref<Bar>.IsAny)).Returns(true);


// matching Func<int>, lazy evaluated
mock.Setup(foo => foo.Add(It.Is<int>(i => i % 2 == 0))).Returns(true); 


// matching ranges
mock.Setup(foo => foo.Add(It.IsInRange<int>(0, 10, Range.Inclusive))).Returns(true); 


// matching regex
mock.Setup(x => x.DoSomethingStringy(It.IsRegex("[a-d]+", RegexOptions.IgnoreCase))).Returns("foo");

mock.Setup(foo => foo.Name).Returns("bar");


// auto-mocking hierarchies (a.k.a. recursive mocks)
mock.Setup(foo => foo.Bar.Baz.Name).Returns("baz");

// expects an invocation to set the value to "foo"
mock.SetupSet(foo => foo.Name = "foo");

// or verify the setter directly
mock.VerifySet(foo => foo.Name = "foo");

// start "tracking" sets/gets to this property
mock.SetupProperty(f => f.Name);

// alternatively, provide a default value for the stubbed property
mock.SetupProperty(f => f.Name, "foo");


// Now you can do:

IFoo foo = mock.Object;
// Initial value was stored
Assert.Equal("foo", foo.Name);

// New value set which changes the initial value
foo.Name = "bar";
Assert.Equal("bar", foo.Name);

mock.SetupAllProperties();

// Setting up an event's `add` and `remove` accessors (requires Moq 4.13 or later):
mock.SetupAdd(m => m.FooEvent += It.IsAny<EventHandler>())...;
mock.SetupRemove(m => m.FooEvent -= It.IsAny<EventHandler>())...;

// Raising an event on the mock
mock.Raise(m => m.FooEvent += null, new FooEventArgs(fooValue));

// Raising an event on the mock that has sender in handler parameters
mock.Raise(m => m.FooEvent += null, this, new FooEventArgs(fooValue));

// Raising an event on a descendant down the hierarchy
mock.Raise(m => m.Child.First.FooEvent += null, new FooEventArgs(fooValue));

// Causing an event to raise automatically when Submit is invoked
mock.Setup(foo => foo.Submit()).Raises(f => f.Sent += null, EventArgs.Empty);
// The raised event would trigger behavior on the object under test, which 
// you would make assertions about later (how its state changed as a consequence, typically)

// Raising a custom event which does not adhere to the EventHandler pattern
public delegate void MyEventHandler(int i, bool b);
public interface IFoo
{
  event MyEventHandler MyEvent; 
}

var mock = new Mock<IFoo>();
...
// Raise passing the custom arguments expected by the event delegate
mock.Raise(foo => foo.MyEvent += null, 25, true);

var mock = new Mock<IFoo>();
var calls = 0;
var callArgs = new List<string>();

mock.Setup(foo => foo.DoSomething("ping"))
    .Callback(() => calls++)
    .Returns(true);

// access invocation arguments
mock.Setup(foo => foo.DoSomething(It.IsAny<string>()))
    .Callback((string s) => callArgs.Add(s))
    .Returns(true);

// alternate equivalent generic method syntax
mock.Setup(foo => foo.DoSomething(It.IsAny<string>()))
    .Callback<string>(s => callArgs.Add(s))
    .Returns(true);

// access arguments for methods with multiple parameters
mock.Setup(foo => foo.DoSomething(It.IsAny<int>(), It.IsAny<string>()))
    .Callback<int, string>((i, s) => callArgs.Add(s))
    .Returns(true);

// callbacks can be specified before and after invocation
mock.Setup(foo => foo.DoSomething("ping"))
    .Callback(() => Console.WriteLine("Before returns"))
    .Returns(true)
    .Callback(() => Console.WriteLine("After returns"));

// callbacks for methods with `ref` / `out` parameters are possible but require some work (and Moq 4.8 or later):
delegate void SubmitCallback(ref Bar bar);

mock.Setup(foo => foo.Submit(ref It.Ref<Bar>.IsAny))
    .Callback(new SubmitCallback((ref Bar bar) => Console.WriteLine("Submitting a Bar!")));

// returning different values on each invocation
var mock = new Mock<IFoo>();
var calls = 0;
mock.Setup(foo => foo.GetCount())
	.Callback(() => calls++)
	.Returns(() => calls);
// returns 0 on first invocation, 1 on the next, and so on
Console.WriteLine(mock.Object.GetCount());

// access invocation arguments and set to mock setup property
mock.SetupProperty(foo=>foo.Bar);
mock.Setup(foo => foo.DoSomething(It.IsAny<string>()))
    .Callback((string s) => mock.Object.Bar=s)
    .Returns(true);

mock.Verify(foo => foo.DoSomething("ping"));

// Verify with custom error message for failure
mock.Verify(foo => foo.DoSomething("ping"), "When doing operation X, the service should be pinged always");

// Method should never be called
mock.Verify(foo => foo.DoSomething("ping"), Times.Never());

// Called at least once
mock.Verify(foo => foo.DoSomething("ping"), Times.AtLeastOnce());

// Verify getter invocation, regardless of value.
mock.VerifyGet(foo => foo.Name);

// Verify setter invocation, regardless of value.
mock.VerifySet(foo => foo.Name);

// Verify setter called with specific value
mock.VerifySet(foo => foo.Name ="foo");

// Verify setter with an argument matcher
mock.VerifySet(foo => foo.Value = It.IsInRange(1, 5, Range.Inclusive));

// Verify event accessors (requires Moq 4.13 or later):
mock.VerifyAdd(foo => foo.FooEvent += It.IsAny<EventHandler>());
mock.VerifyRemove(foo => foo.FooEvent -= It.IsAny<EventHandler>());

// Verify that no other invocations were made other than those already verified (requires Moq 4.8 or later)
mock.VerifyNoOtherCalls();

// get mock from a mocked instance
IFoo foo = // get mock instance somehow
var fooMock = Mock.Get(foo);
fooMock.Setup(f => f.GetCount()).Returns(42);


// implementing multiple interfaces in mock
var mock = new Mock<IFoo>();
var disposableFoo = mock.As<IDisposable>();
// now the IFoo mock also implements IDisposable :)
disposableFoo.Setup(disposable => disposable.Dispose());

// implementing multiple interfaces in single mock
var mock = new Mock<IFoo>();
mock.Setup(foo => foo.Name).Returns("Fred");
mock.As<IDisposable>().Setup(disposable => disposable.Dispose());


// custom matchers
mock.Setup(foo => foo.DoSomething(IsLarge())).Throws<ArgumentException>();
...
[Matcher]
public string IsLarge() 
{ 
  return Match.Create<string>(s => !String.IsNullOrEmpty(s) && s.Length > 100);
}

public interface IFoo
{
    bool M1<T>();
    bool M2<T>(T arg);
}

var mock = new Mock<IFoo>();

mock.Setup(m => m.M1<object>()).Returns(true);

// matches any type argument:
mock.Setup(m => m.M1<It.IsAnyType>()).Returns(true);

// matches only type arguments that are subtypes of / implement T:
mock.Setup(m => m.M1<It.IsSubtype<T>>()).Returns(true);

// use of type matchers is allowed in the argument list:
mock.Setup(m => m.M2(It.IsAny<It.IsAnyType>())).Returns(true);
mock.Setup(m => m.M2(It.IsAny<It.IsSubtype<T>>())).Returns(true);

var services = Mock.Of<IServiceProvider>(sp =>
    sp.GetService(typeof(IRepository)) == Mock.Of<IRepository>(r => r.IsAuthenticated == true) &&
    sp.GetService(typeof(IAuthentication)) == Mock.Of<IAuthentication>(a => a.AuthenticationType == "OAuth"));

// Multiple setups on a single mock and its recursive mocks
ControllerContext context = Mock.Of<ControllerContext>(ctx =>
     ctx.HttpContext.User.Identity.Name == "kzu" &&
     ctx.HttpContext.Request.IsAuthenticated == true &&
     ctx.HttpContext.Request.Url == new Uri("http://moq.github.io/moq4/") &&
     ctx.HttpContext.Response.ContentType == "application/xml");

// Setting up multiple chained mocks:
var context = Mock.Of<ControllerContext>(ctx =>
     ctx.HttpContext.Request.Url == new Uri("http://moqthis.me") &&
     ctx.HttpContext.Response.ContentType == "application/xml" &&
     // Chained mock specification
     ctx.HttpContext.GetSection("server") == Mock.Of<ServerSection>(config =>
         config.Server.ServerUrl == new Uri("http://moqthis.com/api")));