Getting Started

Imposter can be installed from Nuget or Myget. Configure either Nuget or MyGet as your package source and install the package.

Install-Package Appify.FluentImposter.AspnetCore

Currently, the package supports AspnetCore projects only.

As a first step, Create a .Net Core console application and build the WebHost.

static void Main(string[] args)
{
    var host =  WebHost.CreateDefaultBuilder(args)
           .UseUrls("http://localhost:5000")
           .UseKestrel()
           .UseStartup<Startup>()
           .Build();

    host.Start();

    Console.ReadLine();
}

This will create a base Url for the imposters.

1. 1. 1. Create your first Imposter

Creating an Imposter is easy. Just create a class and implement ```IImposter``` interface.

For example, below imposter would stub the REST resource which creates a user.

public class CustomerImposter: IImposter
{
        public Imposter Build()
        {
            return new ImposterDefinition("CustomersStub")
                    .DeclareResource("/api/Customers", HttpMethod.Post)
                    .When(r => r.Content.Contains("Name:Jack"))
                    .Then(new FailedToCreateCustomerResponseCreator())
                    .Build();
        }
}

The Fluent Api helps to build an imposter easily. In this case, an imposter with name ```CreateUserStub``` is being built, which stubs a REST resource ```http://localhost:5000/users``` and accepts ```Post``` requests.

You can define conditions when this imposter should be invoked. In this case, when the request body contains an email address ```[email protected]``` then this imposter will be invoked and will respond with a fake response.

1. 1. 1. 1. Creating fake response.

Fake responses are easy to create. Just Create a class and implement ```IResponseCreator``` interface as shown below.

public class FailedToCreateCustomerResponseCreator : IResponseCreator
{
        public Response CreateResponse()
        {
            var orderCreatedResponse = new CreateCustomerResponse()
                                       {
                                           Message = "Customer creation failed.",
                                       };

            return new ResponseBuilder().WithContent(orderCreatedResponse, new JsonContentSerializer())
                                        .WithStatusCode(HttpStatusCode.InternalServerError)
                                        .Build();
        }
}

The ```ResponseBuilder``` will help you build the ```Response```.

1. 1. 1. Use the Imposter

```
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            ImpostersAsStubConfiguration stubConfiguration =
                    new ImpostersAsStubConfiguration(new StubImpostersBuilder()
                                                             .CreateStubImposters());

            app.UseStubImposters(stubConfiguration);

            /*Uncomment below code when DynamoDB is available at http://localhost:8000*/

            //ImpostersAsMockConfiguration mockConfiguration =
            //        new ImpostersAsMockConfiguration(new MockImpostersBuilder()
            //                                                 .CreateMockImposters(),
            //                                         new MocksDataStore()
            //                                                 .Create());

            //app.UseMockImposters(mockConfiguration);
}

As simple as that. ```ImpostersAsStubConfiguration ``` accepts an array of Imposters and ```UseStubImposters``` extension method of ```IApplicationBuilder``` accpets the ```ImpostersAsStubConfiguration ``` to host the imposters as REST resources.

Apart from the above, you need to call ```AddRouting``` on the ```IServiceCollection``` instance as shown below. The reason, you'd need to do that is because the imposter middleware creates and add ```Routes``` for each imposter REST resource. Without adding routing, imposters will not be able to receive requests from the client.

public void ConfigureServices(IServiceCollection services)
{
    services.AddRouting();
}