Changed CsvConfiguration property ReadEmptyStringAsNull to ReadEmptyFieldsAsDefault for clarity

The original property has been obsoleted but left as a facade

Author: michelebastione

src/MiniExcel.Csv/CsvConfiguration.cs

@@ -11,7 +11,19 @@ public class CsvConfiguration : MiniExcelBaseConfiguration
     public char Seperator { get; set; } = ',';
     public string NewLine { get; set; } = "\r\n";
     public bool ReadLineBreaksWithinQuotes { get; set; } = true;
-    public bool ReadEmptyStringAsNull { get; set; } = false;
+
+    /// <summary>
+    /// When set to true, empty fields will be converted to null when queried as strings,
+    /// or to the default value of the corresponding mapped type. Default is false. 
+    /// </summary>
+    public bool ReadEmptyFieldsAsDefault { get; set; } = false;
+    
+    [Obsolete("Please use the ReadEmptyFieldsAsDefault property instead")]
+    public bool ReadEmptyStringAsNull
+    {
+        get => ReadEmptyFieldsAsDefault;
+        set => ReadEmptyFieldsAsDefault = value;
+    }
 
     /// <summary>
     /// When set to true, rows with fewer columns than the header are padded with default values

src/MiniExcel.Csv/CsvReader.cs

@@ -108,7 +108,7 @@ internal CsvReader(Stream stream, IMiniExcelConfiguration? configuration, bool l
             // todo: can we find a way to remove the redundant cell conversions for CSV?
             var maxCol = (_config.FillMissingColumns ? headRows.Count : read.Length) - 1;
             var cell = ExpandoHelper.CreateEmptyByIndices(maxCol, 0);
-            if (_config.ReadEmptyStringAsNull)
+            if (_config.ReadEmptyFieldsAsDefault)
             {
                 for (int i = 0; i <= read.Length - 1; i++)
                     cell[CellReferenceConverter.GetAlphabeticalIndex(i)] = read[i] is var value and not "" ? value : null;

tests/MiniExcel.Csv.Tests/Issues/GithubIssuesTests.cs

@@ -695,7 +695,7 @@ public void Issue979NoHeader()
         var csvConfig = new CsvConfiguration
         {
             AlwaysQuote = true,
-            ReadEmptyStringAsNull =  true
+            ReadEmptyFieldsAsDefault =  true
         };
 
         var data = """

tests/MiniExcel.Csv.Tests/Main/MiniExcelCsvAsyncTests.cs

@@ -328,7 +328,7 @@ await _csvExporter.ExportAsync(path, new[]
             Assert.Equal(string.Empty, rows[1].C2);
         }
 
-        var config = new CsvConfiguration { ReadEmptyStringAsNull = true };
+        var config = new CsvConfiguration { ReadEmptyFieldsAsDefault = true };
         await using (var stream = File.OpenRead(path))
         {
             var rows = _csvImporter.Query<TestDto>(stream, configuration: config).ToList();