Allow retrieving null instead of DBNull with GetValues.

CHANGELOG.md

@@ -1,3 +1,14 @@
+## 4.6.0 (2019-06-03)
+**Summary** - Support replacing `DBNull` with `null` when calling `GetValues` on an `IDataRecord`.
+
+### New Features
+When working with ADO.NET classes, you often have to deal with `null`s by checking for instances of `DBNull`. Most of the time, this involves calling `IDataRecord.IsDBNull()` or comparing values to `DBNull.Value`. The `DataRecordExtensions` class provides a lot of convenience methods, like `GetNullableString`, that save you from having to distinguish between `null` and `DBNull` all the time. The `FlatFileDataReader` and `DataTableExtensions` classes also provide a lot of features/options surrounding `null` handling. One area where this was overlooked was in the `DataRecordExtensions.GetValues` method.
+
+It was decided that `object[] GetValues()` *(extension)* and `int GetValues(object[])` *(built-in)* should have similar semantics, so instead an optional parameter was added: `replaceDBNulls` that allows specifying whether `DBNull`s should be replaced in the destination array or not (defaults to keeping `DBNull`s). An additional extension: `int GetValues(object[], bool)` was added to provide similar semantics for the built-in method.
+
+### Other
+There were also some tests failing due to culture-specific date formatting. Those unit tests were updated to format dates in a culture-insensitive way.
+
 ## 4.5.0 (2019-05-29)
 **Summary** - Disable wrapping delimited values in quotes.
 

FlatFiles.Test/DataRecordExtensionsTester.cs

@@ -69,17 +69,6 @@ public void TestNullableExtensions_AllNotNull()
             Assert.IsFalse(dataReader.Read(), "Too many records were read.");
         }
 
-
-        [TestMethod]
-        public void TestGetValues_DbNullToNull()
-        {
-            var record = new MockDataRecord();
-            var values = record.GetValues();
-
-            Assert.AreEqual(6, values.Length);
-            Assert.AreEqual(null, values[2]);
-        }
-
         private static SeparatedValueSchema GetSchema()
         {
             var mapper = SeparatedValueTypeMapper.Define(() => new NullableValues());
@@ -124,12 +113,60 @@ public class NullableValues
             public DayOfWeek? EnumValue { get; set; }
         }
 
-        private class MockDataRecord : IDataRecord
+        [TestMethod]
+        public void TestGetValues_DBNullToNull()
+        {
+            var record = new FakeDataRecord(new object[]
+            {
+                0, DateTime.UnixEpoch, DBNull.Value, 3.14159, 3.14159m, "A String"
+            });
+            var values = record.GetValues(replaceDBNulls: true);
+            Assert.AreEqual(6, values.Length);
+            Assert.AreEqual(null, values[2]);
+        }
+
+        [TestMethod]
+        public void TestGetValues_LargerArray()
         {
-            private readonly object[] _values =
+            var record = new FakeDataRecord(new object[]
             {
                 0, DateTime.UnixEpoch, DBNull.Value, 3.14159, 3.14159m, "A String"
+            });
+            var values = new object[10];
+            int length = record.GetValues(values);
+            Assert.AreEqual(6, length);
+            var expected = new object[]
+            {
+                0, DateTime.UnixEpoch, DBNull.Value, 3.14159, 3.14159m, "A String", null, null, null, null
             };
+            CollectionAssert.AreEqual(expected, values);
+        }
+
+        [TestMethod]
+        public void TestGetValues_LargerArray_DBNullToNull()
+        {
+            var record = new FakeDataRecord(new object[]
+            {
+                0, DateTime.UnixEpoch, DBNull.Value, 3.14159, 3.14159m, "A String"
+            });
+            var values = new object[10];
+            int length = record.GetValues(values, replaceDBNulls: true);
+            Assert.AreEqual(6, length);
+            var expected = new object[]
+            {
+                0, DateTime.UnixEpoch, null, 3.14159, 3.14159m, "A String", null, null, null, null
+            };
+            CollectionAssert.AreEqual(expected, values);
+        }
+
+        private class FakeDataRecord : IDataRecord
+        {
+            public FakeDataRecord(object[] values)
+            {
+                Values = values;
+            }
+
+            public object[] Values { get; }
 
             public bool GetBoolean(int i)
             {
@@ -233,21 +270,14 @@ public object GetValue(int i)
 
             public int GetValues(object[] values)
             {
-                int i;
-                for (i = 0; i < values.Length && i < _values.Length; i++)
-                {
-                    values[i] = _values[i];
-                }
-
-                return i;
+                int length = Math.Min(values.Length, Values.Length);
+                Array.Copy(Values, values, length);
+                return length;
             }
 
-            public bool IsDBNull(int i)
-            {
-                throw new NotImplementedException();
-            }
+            public bool IsDBNull(int i) => Values[i] == null || Values[i] == DBNull.Value;
 
-            public int FieldCount => _values.Length;
+            public int FieldCount => Values.Length;
 
             public object this[int i]
             {

FlatFiles.Test/DateTimeColumnTester.cs

@@ -89,7 +89,7 @@ public void TestParse_FormatProvider_FormatString_ParsesExactly()
                 InputFormat = "d",
                 FormatProvider = CultureInfo.InvariantCulture
             };
-            DateTime actual = (DateTime)column.Parse(null, "1/19/2013");
+            DateTime actual = (DateTime)column.Parse(null, "01/19/2013");
             DateTime expected = new DateTime(2013, 1, 19);
             Assert.AreEqual(expected, actual);
         }

FlatFiles/DataRecordExtensions.cs

@@ -1018,19 +1018,36 @@ private static object ToEnum(Type type, object value)
         /// Creates an array of objects with the column values of the current record.
         /// </summary>
         /// <param name="record">The IDataRecord to get the values for.</param>
+        /// <param name="replaceDBNulls">Indicates whether DBNull instances should be replaced with nulls.</param>
         /// <returns>An array of objects with the column values of the current record.</returns>
-        public static object[] GetValues(this IDataRecord record)
+        public static object[] GetValues(this IDataRecord record, bool replaceDBNulls = false)
         {
             var values = new object[record.FieldCount];
-            record.GetValues(values);
-            for (int i = 0; i < values.Length; i++)
+            record.GetValues(values, replaceDBNulls);
+            return values;
+        }
+
+        /// <summary>
+        /// Populates an array of objects with the column values of the current record.
+        /// </summary>
+        /// <param name="record">The IDataRecord to get the values for.</param>
+        /// <param name="values">The array to store the values in.</param>
+        /// <param name="replaceDBNulls">Indicates whether DBNull instances should be replaced with nulls.</param>
+        /// <returns>The number of objects copied to the array.</returns>
+        public static int GetValues(this IDataRecord record, object[] values, bool replaceDBNulls)
+        {
+            int result = record.GetValues(values);
+            if (replaceDBNulls)
             {
-                if (values[i] == DBNull.Value)
+                for (int index = 0; index != result; ++index)
                 {
-                    values[i] = null;
+                    if (values[index] == DBNull.Value)
+                    {
+                        values[index] = null;
+                    }
                 }
             }
-            return values;
+            return result;
         }
 
         #endregion

FlatFiles/FlatFiles.csproj

@@ -10,10 +10,10 @@
     <RepositoryUrl>https://github.com/jehugaleahsa/FlatFiles.git</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>csv;comma;tab;separated;value;delimited;flat;file;fixed;width;fixed-width;length;fixed-length;parser;parsing;parse</PackageTags>
-    <PackageReleaseNotes>Allow disabling quotes in delimited files.</PackageReleaseNotes>
+    <PackageReleaseNotes>Support replacing DBNull with null when reading from IDataRecord.</PackageReleaseNotes>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>FlatFiles.snk</AssemblyOriginatorKeyFile>
-    <Version>4.5.0</Version>
+    <Version>4.6.0</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net451' ">
@@ -27,8 +27,8 @@
   <PropertyGroup>
     <LangVersion>7.3</LangVersion>
     <PackageIconUrl>https://raw.githubusercontent.com/jehugaleahsa/FlatFiles/master/icon.png</PackageIconUrl>
-    <AssemblyVersion>4.5.0.0</AssemblyVersion>
-    <FileVersion>4.5.0.0</FileVersion>
+    <AssemblyVersion>4.6.0.0</AssemblyVersion>
+    <FileVersion>4.6.0.0</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|netstandard1.6|AnyCPU'">