c# - Moq Mock lambda expression -

i trying mock repository on lambda expression executed. method want execute looks this:

public selectlistitem getprotocolbyid(int protocolid) {     var protocol = unitofwork.protocolrepository.findall(s => s.protocol_id == protocolid).firstordefault();     return new selectlistitem()     {         text = protocol.user_defined_id,         value = protocolid.tostring()     }; } 

i created mockrepository in class

protected mockrepository mockrepository = new mockrepository(mockbehavior.default); 

i have unitofwork , protocols repositories , mock them this:

var protocolrepositorymock = mockrepository.create<irepository<protocol>>(); var unitofworkrbmmock = mockrepository.create<iunitofworkrbm>(); 

the findall method irepository looks :

ienumerable<tentity> findall(expression<func<tentity, bool>> where, params expression<func<tentity, object>>[] includes); 

and definition of irepository in iunitofworkrbm one:

irepository<protocol> protocolrepository { get; set; } 

i have tried mock unitofworkmock able execute lambda expression this:

 unitofworkrbmmock.setup(s => s.protocolrepository.findall(it.isany<expression<func<protocol, bool>>>()))                 .returns(new func<expression<func<protocol, bool>>, ienumerable<protocol>>(                 expr => protocolslist.where(expr.compile()))); 

but when try call getprotocolbyid method, protocol comes null.

any ideas on doing wrong here ?

the value of expression provided can accessed in returns method. use filter fake list

review following minimal example used solve problem.

[testmethod] public void _mytestmethod() {     //arrange     var expectedprotocolid = 1;     var protocolslist = new list<protocol> {         new protocol {             protocol_id = expectedprotocolid,             user_defined_id = "some user defined id"         },         new protocol {             protocol_id = 2,             user_defined_id = "some other user defined id"         }     };      var unitofworkrbmmock = new mock<iunitofworkrbm>();      unitofworkrbmmock         .setup(_ => _.protocolrepository.findall(it.isany<expression<func<protocol, bool>>>(), it.isany<expression<func<protocol, object>>[]>()))         .returns<expression<func<protocol, bool>>, expression<func<protocol, object>>[]>((expr, includes) => protocolslist.where(expr.compile()));      var sut = new sut(unitofworkrbmmock.object);      //act     var result = sut.getprotocolbyid(expectedprotocolid);      //assert      assert.isnotnull(result); }   class sut {     private iunitofworkrbm unitofwork;      public sut(iunitofworkrbm unitofworkrbm) {         this.unitofwork = unitofworkrbm;     }      public selectlistitem getprotocolbyid(int protocolid) {         var protocol = unitofwork.protocolrepository.findall(s => s.protocol_id == protocolid).firstordefault();         return new selectlistitem() {             text = protocol.user_defined_id,             value = protocolid.tostring()         };     } }  public interface iunitofworkrbm {     irepository<protocol> protocolrepository { get; set; } }  public interface irepository<tentity> {     ienumerable<tentity> findall(expression<func<tentity, bool>> where, params expression<func<tentity, object>>[] includes); }  public class protocol {     public int protocol_id { get; set; }     public string user_defined_id { get; set; } }