using Dapper;

using Moq;

using Moq.Dapper;

using System;

using System.Collections.Generic;

using System.Data;

using System.Data.Common;

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

​

    /// <summary>

    /// Represents a P&L department

    /// </summary>

    public class ProfitAndLossDepartment

    {

        /// <summary>

        /// Gets or sets the Profit and Loss Department number.

        /// </summary>

        public short PlDeptNumber { get; set; }

​

        /// <summary>

        /// Gets or sets the Profit and Loss Department name.

        /// </summary>

        public string PlDeptName { get; set; }

    }

    public static async Task<int> AddPlDeptsAsync(IEnumerable<ProfitAndLossDepartment> plDeptsToAdd, IDbConnection dbConnection, IDbTransaction dbTransaction)

    {

        Console.WriteLine($"AddPlDeptsAsync: Received {plDeptsToAdd.Count()} objects.");

        string insertQuery = @"

                INSERT INTO pl_depts (pl_deptnum, pl_deptname, store_pro_flag) 

                VALUES (@PlDeptNumber, @PlDeptName, 0)";

​

        var numAdded = await dbConnection.ExecuteAsync(insertQuery, plDeptsToAdd, dbTransaction, null, null);

​

        Console.WriteLine($"AddPlDeptsAsync: {numAdded} objects were reported as added to the database.");

​

        return numAdded;

    }

    public static void Main()

    {       

        var dbConnection = new Mock<DbConnection>();

        var dbTransaction = new Mock<DbTransaction>();

        dbConnection.As<IDbConnection>()

            .Setup(c => c.BeginTransaction())

            .Returns(dbTransaction.Object);

        ProfitAndLossDepartment[] testResult = new ProfitAndLossDepartment[]

        {

            new ProfitAndLossDepartment { PlDeptNumber = 1, PlDeptName = "First" },

            new ProfitAndLossDepartment { PlDeptNumber = 2, PlDeptName = "Second" },

        };

        ProfitAndLossDepartment[] plDeptsAdded = null;

​

        // *** TEST 1

        // **********

        // This (almost) works. The record count returned by the call to AddPlDeptsAsync returns a record count of n^2.

        // I logged this as bug on the Moq.Dapper repo: https://github.com/UnoSD/Moq.Dapper/issues/46

        Console.WriteLine("TEST 1...");

        dbConnection.SetupDapperAsync(c => c.ExecuteAsync(It.IsAny<string>(), It.IsAny<object>(), It.IsAny<IDbTransaction>(), It.IsAny<int?>(), It.IsAny<CommandType?>()))

            .ReturnsAsync(testResult.Length);

​

        var numRecsAdded = AddPlDeptsAsync(testResult, dbConnection.Object, dbTransaction.Object).GetAwaiter().GetResult();             

        Console.WriteLine($"A num rec count of {numRecsAdded} was returned from the call to AddPlDeptsAsync() even though ExecuteAsync() was set up to return {testResult.Length}\r\n");

        // *** TEST 2

        // **********

        // The delegate specified in .Callback() doesn't do anything even though it should.

        Console.WriteLine("TEST 2...");

        dbConnection.SetupDapperAsync(c => c.ExecuteAsync(It.IsAny<string>(), It.IsAny<object>(), It.IsAny<IDbTransaction>(), It.IsAny<int?>(), It.IsAny<CommandType?>()))

            .Callback((string sql, object arg, IDbTransaction transaction, int? commandTimeout, CommandType? commandType) => plDeptsAdded = (arg as IEnumerable<ProfitAndLossDepartment>).ToArray());       

        AddPlDeptsAsync(testResult, dbConnection.Object, dbTransaction.Object).GetAwaiter();                

        Console.WriteLine($"The delegate injected into ExecuteAsync() returned {plDeptsAdded?.Length ?? 0} objects even though a collection of {testResult.Length} objects was passed to it via AddPlDeptsAsync().\r\n");   

        // *** TEST 3

        // **********

        // Chaining .Callback() with .SetupDapperAsync() and .ReturnsAsync() throws an exception. No call to AddPlDeptsAsync is necessary to cause the failure.

        Console.WriteLine("TEST 3...");

        dbConnection.SetupDapperAsync(c => c.ExecuteAsync(It.IsAny<string>(), It.IsAny<object>(), It.IsAny<IDbTransaction>(), It.IsAny<int?>(), It.IsAny<CommandType?>()))

            .Callback((string sql, object arg, IDbTransaction transaction, int? commandTimeout, CommandType? commandType) => plDeptsAdded = (arg as IEnumerable<ProfitAndLossDepartment>).ToArray())

            .ReturnsAsync(testResult.Length);

    }

}