How to set the return value of MS Fakes object?

问题

I have generated an OData Client code with the OData V4 Client Code Generator. The generated code cannot be unit tested without MS Fakes so I generated a fake assembly from it. Now I have a problem of how to actually set the return value of the methods.

The "core" class in the generated code is called System:

[global::Microsoft.OData.Client.OriginalNameAttribute("System")]
public partial class System : global::Microsoft.OData.Client.DataServiceContext
{
    /// <summary>
    /// Initialize a new System object.
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.OData.Client.Design.T4", "2.4.0")]
    public System(global::System.Uri serviceRoot) : 
            base(serviceRoot, global::Microsoft.OData.Client.ODataProtocolVersion.V4)
    {
        this.ResolveName = new global::System.Func<global::System.Type, string>(this.ResolveNameFromType);
        this.ResolveType = new global::System.Func<string, global::System.Type>(this.ResolveTypeFromName);
        this.OnContextCreated();
        this.Format.LoadServiceModel = GeneratedEdmModel.GetInstance;
        this.Format.UseJson();
    }

    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.OData.Client.Design.T4", "2.4.0")]
    [global::Microsoft.OData.Client.OriginalNameAttribute("salesorders")]
    public global::Microsoft.OData.Client.DataServiceQuery<Salesorder> Salesorders
    {
        get
        {
            if ((this._Salesorders == null))
            {
                this._Salesorders = base.CreateQuery<Salesorder>("salesorders");
            }
            return this._Salesorders;
        }
    }
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.OData.Client.Design.T4", "2.4.0")]
    private global::Microsoft.OData.Client.DataServiceQuery<Salesorder> _Salesorders;

    ... continues from here and contains all the strongly typed classes...
}

Now as you can see the property Salesorders is DataServiceQuery<Salesorder> which takes a Linq expression as a parameter.

I've tried to set the query by hand, but it doesn't work and also it seem a bit redundant to specify the actual query in a test case. Basically all I need is the method to return a List (or Enumrable) like I would do it if I could use Moq.

EDIT: I found an old article about using Fakes with the older CRM code generator, but it doesn't help me in this case much (https://zhongchenzhou.wordpress.com/2012/07/10/dynamics-crm-2011-unit-test-part-2-microsoft-fakes-with-linq-query)

    _client = new ODataClient.Microsoft.Dynamics.CRM.Fakes.StubSystem(new System.Uri(...
    _dao = new DataAccess.DataAccess(_client);

            using (ShimsContext.Create())
            {
                var query = from a in _client.Salesorders select a;

                ODataClient.Microsoft.Dynamics.CRM.Fakes.ShimSystem.AllInstances.SalesordersGet = (c) =>
                    {
                        return new Microsoft.OData.Client.DataServiceQuery<Salesorder>( // how?
                    };

// This fails                _dao.GetSalesordersByAccountAndContactId(Guid.NewGuid().ToString(), Guid.NewGuid().ToString());
            }

回答1:

using (ShimsContext.Create())
{
    var client = new ODataClient.Microsoft.Dynamics.CRM.Fakes.ShimSystem();
    IDataAccess dao = new DataAccess.DataAccess(client);

    var salesorders = new List<Salesorder>
    {
        new Salesorder()
    };

    IQueryable<Salesorder> queryableData = salesorders.AsQueryable();

    var queryShim = new Microsoft.OData.Client.Fakes.ShimDataServiceQuery<Salesorder>();
    queryShim.ExpressionGet = () => queryableData.Expression;
    queryShim.ElementTypeGet = () => queryableData.ElementType;
    queryShim.ProviderGet = () => queryableData.Provider;
    queryShim.GetEnumerator = () => queryableData.GetEnumerator();

    DataClient.Microsoft.Dynamics.CRM.Fakes.ShimSystem.SalesordersGet = () => queryShim;
}

来源：https://stackoverflow.com/questions/49873513/how-to-set-the-return-value-of-ms-fakes-object

标签

unit-testing

odata

microsoft-fakes