Dapper/Dapper.Tests/DataReaderTests.cs

using System.Collections.Generic;
using System.Linq;
using Xunit;

namespace Dapper.Tests
{
    public class DataReaderTests : TestBase
    {
        [Fact]
        public void GetSameReaderForSameShape()
        {
            var origReader = connection.ExecuteReader("select 'abc' as Name, 123 as Id");
            var origParser = origReader.GetRowParser(typeof(HazNameId));

            var typedParser = origReader.GetRowParser<HazNameId>();

            Assert.True(ReferenceEquals(origParser, typedParser));

            var list = origReader.Parse<HazNameId>().ToList();
            Assert.Single(list);
            Assert.Equal("abc", list[0].Name);
            Assert.Equal(123, list[0].Id);
            origReader.Dispose();

            var secondReader = connection.ExecuteReader("select 'abc' as Name, 123 as Id");
            var secondParser = secondReader.GetRowParser(typeof(HazNameId));
            var thirdParser = secondReader.GetRowParser(typeof(HazNameId), 1);

            list = secondReader.Parse<HazNameId>().ToList();
            Assert.Single(list);
            Assert.Equal("abc", list[0].Name);
            Assert.Equal(123, list[0].Id);
            secondReader.Dispose();

            // now: should be different readers, but same parser
            Assert.False(ReferenceEquals(origReader, secondReader));
            Assert.True(ReferenceEquals(origParser, secondParser));
            Assert.False(ReferenceEquals(secondParser, thirdParser));
        }

        [Fact]
        public void TestTreatIntAsABool()
        {
            // Test we are consistent with direct call to database, see TypeHandlerTests.TestTreatIntAsABool
            using(var reader = connection.ExecuteReader("select CAST(1 AS BIT)"))
                Assert.True(SqlMapper.Parse<bool>(reader).Single());
            using (var reader = connection.ExecuteReader("select 1"))
                Assert.True(SqlMapper.Parse<bool>(reader).Single());
        }

        [Fact]
        public void DiscriminatedUnion()
        {
            List<Discriminated_BaseType> result = new List<Discriminated_BaseType>();
            using (var reader = connection.ExecuteReader(@"
select 'abc' as Name, 1 as Type, 3.0 as Value
union all
select 'def' as Name, 2 as Type, 4.0 as Value"))
            {
                if (reader.Read())
                {
                    var toFoo = reader.GetRowParser<Discriminated_BaseType>(typeof(Discriminated_Foo));
                    var toBar = reader.GetRowParser<Discriminated_BaseType>(typeof(Discriminated_Bar));

                    var col = reader.GetOrdinal("Type");
                    do
                    {
                        switch (reader.GetInt32(col))
                        {
                            case 1:
                                result.Add(toFoo(reader));
                                break;
                            case 2:
                                result.Add(toBar(reader));
                                break;
                        }
                    } while (reader.Read());
                }
            }

            Assert.Equal(2, result.Count);
            Assert.Equal(1, result[0].Type);
            Assert.Equal(2, result[1].Type);
            var foo = (Discriminated_Foo)result[0];
            Assert.Equal("abc", foo.Name);
            var bar = (Discriminated_Bar)result[1];
            Assert.Equal(bar.Value, (float)4.0);
        }

        [Fact]
        public void DiscriminatedUnionWithMultiMapping()
        {
            var result = new List<DiscriminatedWithMultiMapping_BaseType>();
            using (var reader = connection.ExecuteReader(@"
select 'abc' as Name, 1 as Type, 3.0 as Value, 1 as Id, 'zxc' as Name
union all
select 'def' as Name, 2 as Type, 4.0 as Value, 2 as Id, 'qwe' as Name"))
            {
                if (reader.Read())
                {
                    var col = reader.GetOrdinal("Type");
                    var splitOn = reader.GetOrdinal("Id");

                    var toFoo = reader.GetRowParser<DiscriminatedWithMultiMapping_BaseType>(typeof(DiscriminatedWithMultiMapping_Foo), 0, splitOn);
                    var toBar = reader.GetRowParser<DiscriminatedWithMultiMapping_BaseType>(typeof(DiscriminatedWithMultiMapping_Bar), 0, splitOn);
                    var toHaz = reader.GetRowParser<HazNameId>(typeof(HazNameId), splitOn, reader.FieldCount - splitOn);

                    do
                    {
                        DiscriminatedWithMultiMapping_BaseType obj = null;
                        switch (reader.GetInt32(col))
                        {
                            case 1:
                                obj = toFoo(reader);
                                break;
                            case 2:
                                obj = toBar(reader);
                                break;
                        }

                        Assert.NotNull(obj);
                        obj.HazNameIdObject = toHaz(reader);
                        result.Add(obj);

                    } while (reader.Read());
                }
            }

            Assert.Equal(2, result.Count);
            Assert.Equal(1, result[0].Type);
            Assert.Equal(2, result[1].Type);
            var foo = (DiscriminatedWithMultiMapping_Foo)result[0];
            Assert.Equal("abc", foo.Name);
            Assert.Equal(1, foo.HazNameIdObject.Id);
            Assert.Equal("zxc", foo.HazNameIdObject.Name);
            var bar = (DiscriminatedWithMultiMapping_Bar)result[1];
            Assert.Equal(bar.Value, (float)4.0);
            Assert.Equal(2, bar.HazNameIdObject.Id);
            Assert.Equal("qwe", bar.HazNameIdObject.Name);
        }

        private abstract class Discriminated_BaseType
        {
            public abstract int Type { get; }
        }

        private class Discriminated_Foo : Discriminated_BaseType
        {
            public string Name { get; set; }
            public override int Type => 1;
        }

        private class Discriminated_Bar : Discriminated_BaseType
        {
            public float Value { get; set; }
            public override int Type => 2;
        }

        private abstract class DiscriminatedWithMultiMapping_BaseType : Discriminated_BaseType
        {
            public abstract HazNameId HazNameIdObject { get; set; }
        }

        private class DiscriminatedWithMultiMapping_Foo : DiscriminatedWithMultiMapping_BaseType
        {
            public override HazNameId HazNameIdObject { get; set; }
            public string Name { get; set; }
            public override int Type => 1;
        }

        private class DiscriminatedWithMultiMapping_Bar : DiscriminatedWithMultiMapping_BaseType
        {
            public override HazNameId HazNameIdObject { get; set; }
            public float Value { get; set; }
            public override int Type => 2;
        }
    }
}