fix: improve coherency and robusteness of CsvDataReader (#83)

- this[] returns the same value than GetValue
- GetFieldValue also works when no schema is defined.
- FieldType returns object when no schema is defined or field is not defined

PocketCsvReader.Testing/CsvDataReaderTest.cs

@@ -330,7 +330,16 @@ public void GetValue_WithSchemaAndFormatDateTimeAndShort_CorrectParsing(string r
         Assert.That(dataReader.GetFieldType(0), Is.EqualTo(typeof(DateTime)));
         Assert.That(dataReader.GetFieldType(1), Is.EqualTo(typeof(short)));
         Assert.That(dataReader.GetValue(0), Is.EqualTo(new DateTime(2025, 1, 4, 14, 35, 8)));
+        Assert.That(dataReader[0], Is.EqualTo(new DateTime(2025, 1, 4, 14, 35, 8)));
+        Assert.That(dataReader.GetDate(0), Is.EqualTo(new DateOnly(2025, 1, 4)));
+        Assert.That(dataReader.GetTime(0), Is.EqualTo(new TimeOnly(14, 35, 8)));
         Assert.That(dataReader.GetValue(1), Is.EqualTo((short)108));
+        Assert.That(dataReader[1], Is.EqualTo((short)108));
+        Assert.That(dataReader.GetInt32(1), Is.EqualTo(108));
+        Assert.That(dataReader.GetInt64(1), Is.EqualTo((short)108));
+        Assert.That(dataReader.GetFloat(1), Is.EqualTo((float)108));
+        Assert.That(dataReader.GetDouble(1), Is.EqualTo((double)108));
+        Assert.That(dataReader.GetDecimal(1), Is.EqualTo((decimal)108));
     }
 
     [Test]
@@ -367,6 +376,35 @@ public void GetFieldValue_WithSchemaAndFormatDateTimeAndShort_CorrectParsing(str
         Assert.That(dataReader.GetFieldValue<decimal>(1), Is.EqualTo(108m));
     }
 
+    [Test]
+    [TestCase("foo;bar\r\n2025-01-04T14:35:08;108")]
+    public void GetFieldValue_WithoutSchema_CorrectParsing(string record)
+    {
+        var buffer = new MemoryStream(Encoding.UTF8.GetBytes(record));
+
+        var builder = new CsvReaderBuilder()
+            .WithDialect(
+                (dialect) => dialect
+                    .WithDelimiter(';')
+                    .WithHeader(true)
+            );
+        using var dataReader = builder.Build().ToDataReader(buffer);
+        dataReader.Read();
+        Assert.That(dataReader.FieldCount, Is.EqualTo(2));
+        Assert.That(dataReader.GetName(0), Is.EqualTo("foo"));
+        Assert.That(dataReader.GetName(1), Is.EqualTo("bar"));
+        Assert.That(dataReader.GetFieldType(0), Is.EqualTo(typeof(object)));
+        Assert.That(dataReader.GetFieldType(1), Is.EqualTo(typeof(object)));
+        Assert.That(dataReader.GetFieldValue<DateTime>(0), Is.TypeOf<DateTime>());
+        Assert.That(dataReader.GetFieldValue<short>(1), Is.TypeOf<short>());
+        Assert.That(dataReader.GetFieldValue<int>(1), Is.TypeOf<int>());
+        Assert.That(dataReader.GetFieldValue<decimal>(1), Is.TypeOf<decimal>());
+        Assert.That(dataReader.GetFieldValue<DateTime>(0), Is.EqualTo(new DateTime(2025, 1, 4, 14, 35, 8)));
+        Assert.That(dataReader.GetFieldValue<short>(1), Is.EqualTo((short)108));
+        Assert.That(dataReader.GetFieldValue<int>(1), Is.EqualTo(108));
+        Assert.That(dataReader.GetFieldValue<decimal>(1), Is.EqualTo(108m));
+    }
+
     [Test]
     [TestCase("Ansi")]
     [TestCase("Utf16-BE")]

PocketCsvReader/CsvDataReader.cs

@@ -8,6 +8,8 @@
 using System.Threading.Tasks;
 using System.Globalization;
 using PocketCsvReader.Configuration;
+using System.Reflection;
+using System.Xml.Linq;
 
 namespace PocketCsvReader;
 public class CsvDataReader : IDataReader
@@ -141,16 +143,7 @@ private void HandleUnexpectedFields(int expectedLength)
 
     public object this[int i]
     {
-        get
-        {
-            if (i < Record!.FieldSpans.Length && Fields!.Length > 0)
-                return Record.Slice(i).ToString();
-            if (i < Fields!.Length)
-                return Profile.ParserOptimizations.HandleSpecialValues ? Profile.MissingCell : string.Empty;
-            if (Fields!.Length == 0)
-                throw new InvalidOperationException("Values are not defined yet.");
-            throw new IndexOutOfRangeException("Index out of range.");
-        }
+        get => GetValue(i);
     }
 
     public object this[string name]
@@ -160,11 +153,7 @@ public object this[string name]
             if (Fields is null)
                 throw new InvalidOperationException("Fields are not defined yet.");
             var index = Array.IndexOf(Fields, name);
-            if (index < Record!.FieldSpans.Length)
-                return Record.Slice(index).ToString();
-            if (index < Fields!.Length)
-                return Profile.ParserOptimizations.HandleSpecialValues ? Profile.MissingCell : string.Empty;
-            throw new InvalidOperationException($"Field '{name}' not found.");
+            return GetValue(index);
         }
     }
 
@@ -190,7 +179,7 @@ public DateTime GetDateTime(int i)
             var netFormat = new DateTimeFormatConverter().Convert(field.Format);
             return DateTime.ParseExact(GetValueOrThrow(i), netFormat, CultureInfo.InvariantCulture);
         }
-        
+
         return DateTime.Parse(GetValueOrThrow(i), CultureInfo.InvariantCulture);
     }
 
@@ -231,7 +220,11 @@ public DateTimeOffset GetDateTimeOffset(int i)
     public double GetDouble(int i) => double.Parse(GetValueOrThrow(i), CultureInfo.InvariantCulture);
     [return: DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicFields | DynamicallyAccessedMemberTypes.PublicProperties)]
     public Type GetFieldType(int i)
-        => GetFieldDescriptor(i).RuntimeType;
+    {
+        if (TryGetFieldDescriptor(i, out var field))
+            return field.RuntimeType;
+        return typeof(object);
+    }
 
     protected FieldDescriptor GetFieldDescriptor(int i)
     {
@@ -309,6 +302,8 @@ public object GetValue(int i)
     {
         if (i >= FieldCount)
             throw new IndexOutOfRangeException($"Field index '{i}' is out of range.");
+        if (i < Fields!.Length && i >= Record!.FieldSpans.Length)
+            return Profile.ParserOptimizations.HandleSpecialValues ? Profile.MissingCell : string.Empty;
 
         if (!TryGetFieldDescriptor(i, out var field)
             || !TypeFunctions.TryGetFunction(field.RuntimeType, out var func))
@@ -322,8 +317,7 @@ public T GetFieldValue<T>(int i)
         if (i >= FieldCount)
             throw new IndexOutOfRangeException($"Field index '{i}' is out of range.");
 
-        if (!TryGetFieldDescriptor(i, out var field)
-            || !TypeFunctions.TryGetFunction<T>(out var func))
+        if (!TypeFunctions.TryGetFunction<T>(out var func))
             throw new NotImplementedException($"No function registered for type {typeof(T).Name}");
 
         return func.Invoke(i);
@@ -382,7 +376,7 @@ public bool TryGetFunction<T>([NotNullWhen(true)] out Func<int, T>? func)
         {
             if (_typeToFunctionMap.TryGetValue(typeof(T), out var value))
             {
-                func = (Func<int, T>)value; 
+                func = (Func<int, T>)value;
                 return true;
             }
             func = null;