From 2e6cd8a48189ea64e4efdcdb122700e076fd042c Mon Sep 17 00:00:00 2001
From: philipmat <github@philipm.at>
Date: Mon, 21 Sep 2020 18:04:53 -0500
Subject: [PATCH] csv files are written without BOM - fixes #118

---
 alternatives/dotnet/discogs/CsvExporter.cs    |  5 +-
 .../tests/CsvExporterItegrationTests.cs       | 60 +++++++++++++++++++
 2 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 alternatives/dotnet/tests/CsvExporterItegrationTests.cs

diff --git a/alternatives/dotnet/discogs/CsvExporter.cs b/alternatives/dotnet/discogs/CsvExporter.cs
index 06f0204..705799e 100644
--- a/alternatives/dotnet/discogs/CsvExporter.cs
+++ b/alternatives/dotnet/discogs/CsvExporter.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
+using System.Text;
 using System.Threading.Tasks;
 
 namespace discogs
@@ -64,11 +65,11 @@ public async Task ExportAsync(T value)
                     {
                         var fs = File.Create(csvFile, bufferSize: BufferSize);
                         var gzStream = new GZipStream(fs, CompressionMode.Compress, leaveOpen: false);
-                        stream = new StreamWriter(gzStream, encoding: System.Text.Encoding.UTF8);
+                        stream = new StreamWriter(gzStream, encoding: new UTF8Encoding(encoderShouldEmitUTF8Identifier: false));
                     }
                     else
                     {
-                        stream = new StreamWriter(csvFile, append: false, encoding: System.Text.Encoding.UTF8, bufferSize: BufferSize);
+                        stream = new StreamWriter(csvFile, append: false, encoding: new UTF8Encoding(encoderShouldEmitUTF8Identifier: false), bufferSize: BufferSize);
                     }
                     stream.WriteLine(CsvExtensions.ToCsv(kvp.Value));
                     return (csvFile, stream);
diff --git a/alternatives/dotnet/tests/CsvExporterItegrationTests.cs b/alternatives/dotnet/tests/CsvExporterItegrationTests.cs
new file mode 100644
index 0000000..7f72d9c
--- /dev/null
+++ b/alternatives/dotnet/tests/CsvExporterItegrationTests.cs
@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using discogs;
+using FluentAssertions;
+using Xunit;
+
+namespace tests
+{
+   public class CsvExporterIntegrationTests : IDisposable
+    {
+        public static readonly string TestPath = Path.Combine(Path.GetTempPath(), "CvsExporter");
+
+        public CsvExporterIntegrationTests()
+        {
+            // deletes folder as a shorcut to cleaning out and starting the test with blank slate
+            if (Directory.Exists(TestPath)) Directory.Delete(TestPath, recursive: true);
+            Directory.CreateDirectory(TestPath);
+        }
+
+        public void Dispose()
+        {
+            Directory.Delete(TestPath, recursive: true);
+        }
+
+        [Fact]
+        public async Task Export_DoesNotCreateBomAsync()
+        {
+            //Given
+            var exporter = new CsvExporter<SimpleRecord>(TestPath, compress: false);
+            var record = new SimpleRecord();
+        
+            //When
+            await exporter.ExportAsync(record);
+            await exporter.CompleteExportAsync(1);
+        
+            //Then
+            var outputFile = Path.Combine(TestPath, "test_1.csv");
+            File.Exists(outputFile).Should().BeTrue();
+            byte[] content = await File.ReadAllBytesAsync(outputFile);
+
+            content[0].Should().Be((byte)'f', because: "foo is the first word in the file");
+            content[1].Should().Be((byte)'o', because: "foo is the first word in the file");
+        }
+
+        private class SimpleRecord : IExportToCsv
+        {
+            public IEnumerable<(string StreamName, string[] RowValues)> ExportToCsv()
+            {
+                yield return ("test_1", new string[] { "1.0", "1.1" });
+            }
+
+            public IReadOnlyDictionary<string, string[]> GetCsvExportScheme()
+                => new Dictionary<string, string[]> {
+                    ["test_1"] = new string[] { "foo", "bar" }
+                };
+        }
+    }
+}
\ No newline at end of file