From 192165177175f591f10bb12f6985c54a594824f0 Mon Sep 17 00:00:00 2001
From: omerbenda <omerbenda@gmail.com>
Date: Tue, 16 Dec 2025 18:27:41 +0200
Subject: [PATCH] fix(CsvReader.cs): Add a read method to read without skipping
 headers

---
 src/CsvHelper/CsvReader.cs                    | 96 +++++++++++++------
 .../Reading/ShouldSkipRecordTests.cs          | 31 ++++++
 2 files changed, 98 insertions(+), 29 deletions(-)

diff --git a/src/CsvHelper/CsvReader.cs b/src/CsvHelper/CsvReader.cs
index 3fa74c2a0..f5fac97e3 100644
--- a/src/CsvHelper/CsvReader.cs
+++ b/src/CsvHelper/CsvReader.cs
@@ -237,6 +237,50 @@ protected virtual void ValidateHeader(ClassMap map, List<InvalidHeader> invalidH
 		}
 	}
 
+	/// <summary>
+	/// Advances the reader to the header record. Does not skip over records and should not be used to read records.
+	/// You need to call <see cref="Read"/> then <see cref="ReadHeader"/> 
+	/// for the headers to be read.
+	/// </summary>
+	/// <returns>True if there are more records, otherwise false.</returns>
+	public virtual bool PreHeaderRead()
+	{
+		// Don't forget about the async method below!
+
+		bool hasMoreData = parser.Read();
+		hasBeenRead = true;
+
+		currentIndex = -1;
+
+		if (detectColumnCountChanges && hasMoreData)
+		{
+			UpdateColumnCount();
+		}
+
+		return hasMoreData;
+	}
+
+	/// <summary>
+	/// Advances the reader to the header record. Does not skip over records and should not be used to read records.
+	/// You need to call <see cref="ReadAsync"/> then <see cref="ReadHeader"/> 
+	/// for the headers to be read.
+	/// </summary>
+	/// <returns>True if there are more records, otherwise false.</returns>
+	public virtual async Task<bool> PreHeaderReadAsync()
+	{
+		bool hasMoreData = await parser.ReadAsync().ConfigureAwait(false);
+		hasBeenRead = true;
+
+		currentIndex = -1;
+
+		if (detectColumnCountChanges && hasMoreData)
+		{
+			UpdateColumnCount();
+		}
+
+		return hasMoreData;
+	}
+
 	/// <inheritdoc/>
 	public virtual bool Read()
 	{
@@ -254,18 +298,7 @@ public virtual bool Read()
 
 		if (detectColumnCountChanges && hasMoreRecords)
 		{
-			if (prevColumnCount > 0 && prevColumnCount != parser.Count)
-			{
-				var csvException = new BadDataException(string.Empty, parser.RawRecord, context, "An inconsistent number of columns has been detected.");
-
-				var args = new ReadingExceptionOccurredArgs(csvException);
-				if (readingExceptionOccurred?.Invoke(args) ?? true)
-				{
-					throw csvException;
-				}
-			}
-
-			prevColumnCount = parser.Count;
+			UpdateColumnCount();
 		}
 
 		return hasMoreRecords;
@@ -286,21 +319,26 @@ public virtual async Task<bool> ReadAsync()
 
 		if (detectColumnCountChanges && hasMoreRecords)
 		{
-			if (prevColumnCount > 0 && prevColumnCount != parser.Count)
-			{
-				var csvException = new BadDataException(string.Empty, parser.RawRecord, context, "An inconsistent number of columns has been detected.");
+			UpdateColumnCount();
+		}
 
-				var args = new ReadingExceptionOccurredArgs(csvException);
-				if (readingExceptionOccurred?.Invoke(args) ?? true)
-				{
-					throw csvException;
-				}
-			}
+		return hasMoreRecords;
+	}
+
+	private void UpdateColumnCount()
+	{
+		if (prevColumnCount > 0 && prevColumnCount != parser.Count)
+		{
+			var csvException = new BadDataException(string.Empty, parser.RawRecord, context, "An inconsistent number of columns has been detected.");
 
-			prevColumnCount = parser.Count;
+			var args = new ReadingExceptionOccurredArgs(csvException);
+			if (readingExceptionOccurred?.Invoke(args) ?? true)
+			{
+				throw csvException;
+			}
 		}
 
-		return hasMoreRecords;
+		prevColumnCount = parser.Count;
 	}
 
 	/// <inheritdoc/>
@@ -843,7 +881,7 @@ public virtual IEnumerable<T> GetRecords<T>()
 
 		if (hasHeaderRecord && headerRecord == null)
 		{
-			if (!Read())
+			if (!PreHeaderRead())
 			{
 				yield break;
 			}
@@ -924,7 +962,7 @@ public virtual IEnumerable<object> GetRecords(Type type)
 
 		if (hasHeaderRecord && headerRecord == null)
 		{
-			if (!Read())
+			if (!PreHeaderRead())
 			{
 				yield break;
 			}
@@ -989,7 +1027,7 @@ public virtual IEnumerable<T> EnumerateRecords<T>(T record)
 
 		if (hasHeaderRecord && headerRecord == null)
 		{
-			if (!Read())
+			if (!PreHeaderRead())
 			{
 				yield break;
 			}
@@ -1046,7 +1084,7 @@ public virtual IEnumerable<T> EnumerateRecords<T>(T record)
 
 		if (hasHeaderRecord && headerRecord == null)
 		{
-			if (!await ReadAsync().ConfigureAwait(false))
+			if (!await PreHeaderReadAsync().ConfigureAwait(false))
 			{
 				yield break;
 			}
@@ -1128,7 +1166,7 @@ public virtual async IAsyncEnumerable<object> GetRecordsAsync(Type type, [Enumer
 
 		if (hasHeaderRecord && headerRecord == null)
 		{
-			if (!await ReadAsync().ConfigureAwait(false))
+			if (!await PreHeaderReadAsync().ConfigureAwait(false))
 			{
 				yield break;
 			}
@@ -1194,7 +1232,7 @@ public virtual async IAsyncEnumerable<T> EnumerateRecordsAsync<T>(T record, [Enu
 
 		if (hasHeaderRecord && headerRecord == null)
 		{
-			if (!await ReadAsync().ConfigureAwait(false))
+			if (!await PreHeaderReadAsync().ConfigureAwait(false))
 			{
 				yield break;
 			}
diff --git a/tests/CsvHelper.Tests/Reading/ShouldSkipRecordTests.cs b/tests/CsvHelper.Tests/Reading/ShouldSkipRecordTests.cs
index 893785dbd..045a18c97 100644
--- a/tests/CsvHelper.Tests/Reading/ShouldSkipRecordTests.cs
+++ b/tests/CsvHelper.Tests/Reading/ShouldSkipRecordTests.cs
@@ -83,5 +83,36 @@ public void ShouldSkipWithEmptyRows()
 			Assert.Equal("1", csv.GetField(0));
 			Assert.Equal("2", csv.GetField(1));
 		}
+
+		[Fact]
+		public void ShouldSkipIgnoreHeader()
+		{
+			var config = new CsvConfiguration(CultureInfo.InvariantCulture)
+			{
+				ShouldSkipRecord = skipArgs => !skipArgs.Row[0]!.StartsWith("A")
+			};
+
+			var parser = new ParserMock(config)
+			{
+				{ "Name" },
+				{ "Arnold" },
+				{ "Andrew" },
+				{ "Betty" },
+				{ "Frank" }
+			};
+
+			var csv = new CsvReader(parser);
+			var csvReader = new CsvReader(parser);
+			var typeDef = new
+			{
+				Name = string.Empty
+			};
+
+			var records = csvReader.GetRecords(typeDef).ToList();
+
+			Assert.Equal(2, records.Count);
+			Assert.Equal("Arnold", records[0].Name);
+			Assert.Equal("Andrew", records[1].Name);
+		}
 	}
 }