Read from CSV: retarget net10.0, fix the discarded configuration, add the missing data file and real tests

files-csharp/ReadFromCsv/ReadFromCsv/Person.cs

@@ -1,16 +1,15 @@
-using CsvHelper.Configuration.Attributes;
+using CsvHelper.Configuration.Attributes;
 
-namespace ReadFromCsv
+namespace ReadFromCsv;
+
+public class Person
 {
-    public class Person
-    {
-        [Index(0)]
-        public int Id { get; set; }
-        [Index(1)]
-        public string? Name { get; set; }
-        [Index(2)]
-        public bool IsLiving { get; set; }
-        [Index(3)]
-        public DateTime DateOfBirth { get; set; }
-    }
+    [Index(0)]
+    public int Id { get; set; }
+    [Index(1)]
+    public string? Name { get; set; }
+    [Index(2)]
+    public bool IsLiving { get; set; }
+    [Index(3)]
+    public DateTime DateOfBirth { get; set; }
 }

files-csharp/ReadFromCsv/ReadFromCsv/PersonMap.cs

@@ -1,12 +1,13 @@
-using CsvHelper.Configuration;
-using ReadFromCsv;
+using CsvHelper.Configuration;
 
-public class PersonMap : ClassMap<Person> 
-{ 
-    public PersonMap() 
-    { 
-        Map(p => p.Id).Index(0); 
-        Map(p => p.Name).Index(1); 
-        Map(p => p.IsLiving).Index(2); 
-    } 
-}
+namespace ReadFromCsv;
+
+public class PersonMap : ClassMap<Person>
+{
+    public PersonMap()
+    {
+        Map(p => p.Id).Index(0);
+        Map(p => p.Name).Index(1);
+        Map(p => p.IsLiving).Index(2);
+    }
+}

files-csharp/ReadFromCsv/ReadFromCsv/Program.cs

@@ -1,3 +1,6 @@
-using ReadFromCsv;
+using ReadFromCsv;
 
-ReadMethods.ReadPersons();
+foreach (var person in ReadMethods.ReadPersons())
+{
+    Console.WriteLine($"{person.Id} {person.Name} {person.IsLiving}");
+}

files-csharp/ReadFromCsv/ReadFromCsv/ReadFromCsv.csproj

@@ -2,13 +2,19 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CsvHelper" Version="27.2.1" />
+    <PackageReference Include="CsvHelper" Version="33.1.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="filePersons.csv">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
 
 </Project>

files-csharp/ReadFromCsv/ReadFromCsv/ReadMethods.cs

@@ -1,27 +1,25 @@
-using CsvHelper;
+using CsvHelper;
 using CsvHelper.Configuration;
 using System.Globalization;
 
-namespace ReadFromCsv
+namespace ReadFromCsv;
+
+public static class ReadMethods
 {
-    public static class ReadMethods
+    public static List<Person> ReadPersons()
     {
-        public static void ReadPersons()
+        var configuration = new CsvConfiguration(CultureInfo.InvariantCulture)
         {
-            var configuration = new CsvConfiguration(CultureInfo.InvariantCulture)
-            {
-                Delimiter = ",",
-                Comment = '#',
-                HasHeaderRecord = false
-            };
+            Delimiter = ",",
+            Comment = '#',
+            HasHeaderRecord = false
+        };
+
+        using var reader = new StreamReader("filePersons.csv");
+        using var csv = new CsvReader(reader, configuration);
 
-            using (var reader = new StreamReader("filePersons.csv"))
-            using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
-            {
-                csv.Context.RegisterClassMap<PersonMap>();
-                var persons = csv.GetRecords<Person>();
-            }
+        csv.Context.RegisterClassMap<PersonMap>();
 
-        }
+        return csv.GetRecords<Person>().ToList();
     }
 }

files-csharp/ReadFromCsv/ReadFromCsv/filePersons.csv

@@ -0,0 +1,3 @@
+1,John,True,03/05/2006
+2,Steve,False,03/05/2006
+3,James,True,03/05/2006

files-csharp/ReadFromCsv/ReadFromCsvTests/ReadFromCsvTests.cs

@@ -1,5 +1,7 @@
 using CsvHelper;
 using CsvHelper.Configuration;
+using CsvHelper.TypeConversion;
+using Microsoft.VisualBasic.FileIO;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using ReadFromCsv;
 using System;
@@ -9,41 +11,199 @@
 using System.Linq;
 using System.Text;
 
-namespace ReadFromCsvTests
+namespace ReadFromCsvTests;
+
+[TestClass]
+public class ReadFromCsvTests
 {
-    [TestClass]
-    public class ReadFromCsvTests
+    private static CsvReader CreateReader(string csvContent, CsvConfiguration configuration, out StreamReader reader)
+    {
+        var stream = new MemoryStream(Encoding.UTF8.GetBytes(csvContent));
+
+        reader = new StreamReader(stream);
+
+        return new CsvReader(reader, configuration);
+    }
+
+    [TestMethod]
+    public void GivenHeaderlessCsvFile_WhenReadingPersons_ThenEveryFieldIsMapped()
     {
-        [TestMethod]
-        public void GivenCsvFile_WhenReadingPersonsFromCsv_ThenListOfPersonsIsPopulated()
+        var csvFile = "1,John,True,03/05/2006 00:00:00\n"
+            + "2,Steve,False,03/05/2006 00:00:00\n"
+            + "3,James,True,03/05/2006 00:00:00";
+
+        var expectedPersons = new List<Person>
         {
-            string csvFile =
-                @"1, John, True, 03/05/2006 00:00:00
-2, Steve, False, 03/05/2006 00:00:00
-3, James, True, 03/05/2006 00:00:00";
+            new() { Id = 1, Name = "John", IsLiving = true, DateOfBirth = DateTime.Parse("03/05/2006", CultureInfo.InvariantCulture) },
+            new() { Id = 2, Name = "Steve", IsLiving = false, DateOfBirth = DateTime.Parse("03/05/2006", CultureInfo.InvariantCulture) },
+            new() { Id = 3, Name = "James", IsLiving = true, DateOfBirth = DateTime.Parse("03/05/2006", CultureInfo.InvariantCulture) }
+        };
 
-            var expectedPersons = new List<Person>()
-            {
-                new Person { Id = 1, IsLiving = true, Name = "John", DateOfBirth = Convert.ToDateTime("03/05/2006") },
-                new Person { Id = 2, IsLiving = true, Name = "Steve", DateOfBirth = Convert.ToDateTime("03/09/1998") },
-                new Person { Id = 3, IsLiving = true, Name = "James", DateOfBirth = Convert.ToDateTime("03/08/1994") }
-            };
+        var configuration = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = false
+        };
 
-            using (var test_Stream = new MemoryStream(Encoding.UTF8.GetBytes(csvFile)))
+        using var csv = CreateReader(csvFile, configuration, out var reader);
+        using (reader)
+        {
+            var persons = csv.GetRecords<Person>().ToList();
+
+            Assert.AreEqual(expectedPersons.Count, persons.Count);
+
+            for (var i = 0; i < expectedPersons.Count; i++)
             {
-                var config = new CsvConfiguration(CultureInfo.InvariantCulture)
-                {
-                    HasHeaderRecord = false,
-                };
-
-                using (var reader = new StreamReader(test_Stream))
-                using (var csv = new CsvReader(reader, config))
-                {
-                    var records = csv.GetRecords<Person>();
-
-                    Assert.AreEqual(expectedPersons.Count, records.Count());
-                }
+                Assert.AreEqual(expectedPersons[i].Id, persons[i].Id);
+                Assert.AreEqual(expectedPersons[i].Name, persons[i].Name);
+                Assert.AreEqual(expectedPersons[i].IsLiving, persons[i].IsLiving);
+                Assert.AreEqual(expectedPersons[i].DateOfBirth, persons[i].DateOfBirth);
             }
         }
     }
-}
+
+    [TestMethod]
+    public void GivenHeaderlessCsvFile_WhenTheConfigurationIsNotPassedToTheReader_ThenTheFirstRowIsLost()
+    {
+        var csvFile = "1,John,True,03/05/2006 00:00:00\n2,Steve,False,03/05/2006 00:00:00";
+
+        var configuration = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = false
+        };
+
+        using (var csv = CreateReader(csvFile, configuration, out var withConfiguration))
+        using (withConfiguration)
+        {
+            Assert.AreEqual(2, csv.GetRecords<Person>().ToList().Count);
+        }
+
+        var cultureOnly = new CsvConfiguration(CultureInfo.InvariantCulture);
+
+        using (var csv = CreateReader(csvFile, cultureOnly, out var withCulture))
+        using (withCulture)
+        {
+            var persons = csv.GetRecords<Person>().ToList();
+
+            Assert.AreEqual(1, persons.Count);
+            Assert.AreEqual(2, persons[0].Id);
+        }
+    }
+
+    [TestMethod]
+    public void GivenAQuotedComma_WhenReadingTheRow_ThenTheFieldSurvivesIntact()
+    {
+        var csvFile = "Id,Name,IsLiving,DateOfBirth\n1,\"Close, Josh\",true,03/05/2006 00:00:00";
+
+        var configuration = new CsvConfiguration(CultureInfo.InvariantCulture);
+
+        using var csv = CreateReader(csvFile, configuration, out var reader);
+        using (reader)
+        {
+            var persons = csv.GetRecords<Person>().ToList();
+
+            Assert.AreEqual(1, persons.Count);
+            Assert.AreEqual("Close, Josh", persons[0].Name);
+        }
+    }
+
+    [TestMethod]
+    public void GivenACommentLine_WhenAllowCommentsIsFalse_ThenTheCommentIsReadAsData()
+    {
+        var csvFile = "1;John;True;03/05/2006 00:00:00\n% a comment line\n2;Steve;False;03/05/2006 00:00:00";
+
+        var configuration = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = false,
+            Delimiter = ";",
+            Comment = '%'
+        };
+
+        Assert.IsFalse(configuration.AllowComments);
+
+        using var csv = CreateReader(csvFile, configuration, out var reader);
+        using (reader)
+        {
+            Assert.ThrowsExactly<TypeConverterException>(() => csv.GetRecords<Person>().ToList());
+        }
+    }
+
+    [TestMethod]
+    public void GivenACommentLine_WhenAllowCommentsIsTrue_ThenTheCommentIsSkipped()
+    {
+        var csvFile = "1;John;True;03/05/2006 00:00:00\n% a comment line\n2;Steve;False;03/05/2006 00:00:00";
+
+        var configuration = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = false,
+            Delimiter = ";",
+            Comment = '%',
+            AllowComments = true
+        };
+
+        using var csv = CreateReader(csvFile, configuration, out var reader);
+        using (reader)
+        {
+            var persons = csv.GetRecords<Person>().ToList();
+
+            Assert.AreEqual(2, persons.Count);
+            Assert.AreEqual("Steve", persons[1].Name);
+        }
+    }
+
+    [TestMethod]
+    public void GivenAQuotedComma_WhenSplittingTheLine_ThenSplitBreaksItAndTextFieldParserDoesNot()
+    {
+        var row = "1,\"Close, Josh\",true,03/05/2006 00:00:00";
+
+        Assert.AreEqual(5, row.Split(',').Length);
+
+        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(row));
+        using var parser = new TextFieldParser(stream)
+        {
+            TextFieldType = FieldType.Delimited,
+            HasFieldsEnclosedInQuotes = true
+        };
+
+        parser.SetDelimiters(",");
+
+        var fields = parser.ReadFields();
+
+        Assert.IsNotNull(fields);
+        Assert.AreEqual(4, fields.Length);
+        Assert.AreEqual("Close, Josh", fields[1]);
+    }
+
+    [TestMethod]
+    public void GivenAnUnconvertibleField_WhenReadingExceptionOccurredReturnsFalse_ThenTheBadRowIsSkipped()
+    {
+        var csvFile = "1,John,True,03/05/2006 00:00:00\n"
+            + "2,Steve,notabool,03/05/2006 00:00:00\n"
+            + "3,James,True,03/05/2006 00:00:00";
+
+        var strict = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = false
+        };
+
+        using (var csv = CreateReader(csvFile, strict, out var strictReader))
+        using (strictReader)
+        {
+            Assert.ThrowsExactly<TypeConverterException>(() => csv.GetRecords<Person>().ToList());
+        }
+
+        var tolerant = new CsvConfiguration(CultureInfo.InvariantCulture)
+        {
+            HasHeaderRecord = false,
+            ReadingExceptionOccurred = args => false
+        };
+
+        using (var csv = CreateReader(csvFile, tolerant, out var tolerantReader))
+        using (tolerantReader)
+        {
+            var persons = csv.GetRecords<Person>().ToList();
+
+            Assert.AreEqual(2, persons.Count);
+            Assert.AreEqual(3, persons[1].Id);
+        }
+    }
+}

files-csharp/ReadFromCsv/ReadFromCsvTests/ReadFromCsvTests.csproj

@@ -1,18 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <Nullable>enable</Nullable>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CsvHelper" Version="27.2.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="2.2.7" />
-    <PackageReference Include="MSTest.TestFramework" Version="2.2.7" />
-    <PackageReference Include="coverlet.collector" Version="3.1.0" />
+    <PackageReference Include="CsvHelper" Version="33.1.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.10.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="4.4.0" />
+    <PackageReference Include="MSTest.TestFramework" Version="4.4.0" />
+    <PackageReference Include="coverlet.collector" Version="10.0.1" />
   </ItemGroup>
 
   <ItemGroup>