(GH-116) Unit tests to verify that we skip blank lines before the first boundary marker

Author: Jericho

Source/HttpMultipartParser.UnitTests/ParserScenarios/BlankLinesBeforeFirstBoundary.cs

@@ -0,0 +1,64 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace HttpMultipartParser.UnitTests.ParserScenarios
+{
+	public class BlankLinesBeforeFirstBoundary
+	{
+		private static readonly string _testData = TestUtil.TrimAllLines(
+			@"--boundary
+            Content-Disposition: form-data; name=""text""
+
+            textdata
+            --boundary--"
+		);
+
+		// This test case has a few blank lines before the first boundary marker
+		// This unusual scenario is described in GH-116
+		// https://github.com/Http-Multipart-Data-Parser/Http-Multipart-Data-Parser/issues/116
+		private static readonly TestData _testCase = new TestData(
+			$"\n\n\n{_testData}", // Intentionally add a few blank lines before the data. These blank lines should be ignored by the parser when attempting to detect the boundary marker
+			new List<ParameterPart> {
+				new ParameterPart("text", "textdata"),
+			},
+			new List<FilePart>()
+		);
+
+		public BlankLinesBeforeFirstBoundary()
+		{
+			foreach (var filePart in _testCase.ExpectedFileData)
+			{
+				filePart.Data.Position = 0;
+			}
+		}
+
+		/// <summary>
+		///     Tests for correct detection of the boundary in the input stream.
+		/// </summary>
+		[Fact]
+		public void CanAutoDetectBoundary()
+		{
+			using (Stream stream = TestUtil.StringToStream(_testCase.Request, Encoding.UTF8))
+			{
+				var parser = MultipartFormDataParser.Parse(stream);
+				Assert.True(_testCase.Validate(parser));
+			}
+		}
+
+		/// <summary>
+		///     Tests for correct detection of the boundary in the input stream.
+		/// </summary>
+		[Fact]
+		public async Task CanAutoDetectBoundaryAsync()
+		{
+			using (Stream stream = TestUtil.StringToStream(_testCase.Request, Encoding.UTF8))
+			{
+				var parser = await MultipartFormDataParser.ParseAsync(stream, Encoding.UTF8).ConfigureAwait(false);
+				Assert.True(_testCase.Validate(parser));
+			}
+		}
+	}
+}