Fix update functionality

Author: SteveDesmond-ca

src/LibYear.Core/FileTypes/XmlProjectFile.cs

@@ -4,10 +4,18 @@ namespace LibYear.Core.FileTypes;
 
 public abstract class XmlProjectFile : IProjectFile
 {
+	private enum Whitespace
+	{
+		Tabs,
+		FourSpaces,
+		TwoSpaces
+	}
+
 	public string FileName { get; }
 	public IDictionary<string, PackageVersion?> Packages { get; }
 
 	private readonly XDocument _xmlContents;
+	private readonly Whitespace _whitespace;
 	private readonly string _elementName;
 	private readonly string[] _packageAttributeNames;
 	private readonly string _versionAttributeName;
@@ -21,13 +29,20 @@ protected XmlProjectFile(string filename, string contents, string elementName, s
 		_versionAttributeName = versionAttributeName;
 
 		_xmlContents = XDocument.Parse(contents);
+		_whitespace = DetermineWhitespace(contents);
+
 		Packages = _xmlContents.Descendants(elementName)
 			.ToDictionary(
 				d => packageAttributeNames.Select(p => d.Attribute(p)?.Value ?? d.Element(p)?.Value).FirstOrDefault(v => v != null)!,
 				d => ParseCurrentVersion(d, versionAttributeName)
 			);
 	}
 
+	private static Whitespace DetermineWhitespace(string contents)
+		=> contents.Contains("\n\t") ? Whitespace.Tabs
+			: contents.Contains("\n  <") ? Whitespace.TwoSpaces
+			: Whitespace.FourSpaces;
+
 	public string Update(IReadOnlyCollection<Result> results)
 	{
 		foreach (var result in results.Where(r => r.Latest != null))
@@ -36,7 +51,13 @@ public string Update(IReadOnlyCollection<Result> results)
 				UpdateElement(element, result.Latest!.Version.ToString());
 		}
 
-		return _xmlContents.ToString();
+		var xml = _xmlContents.ToString();
+		return _whitespace switch
+		{
+			Whitespace.Tabs => xml.Replace("  ", "\t"),
+			Whitespace.FourSpaces => xml.Replace("  ", "    "),
+			_ => xml
+		};
 	}
 
 	private PackageVersion? ParseCurrentVersion(XElement element, string versionAttributeName)
@@ -71,7 +92,7 @@ private void UpdateElement(XElement element, string latestVersion)
 	private XElement[] GetMatchingElements(Result result)
 		=> _xmlContents.Descendants(_elementName)
 			.Where(d => _packageAttributeNames.Any(attributeName => (d.Attribute(attributeName)?.Value ?? d.Element(attributeName)?.Value) == result.Name
-					&& (d.Attribute(_versionAttributeName)?.Value ?? d.Element(_versionAttributeName)?.Value) == result.Installed?.Version.ToString()
+			                                                        && (d.Attribute(_versionAttributeName)?.Value ?? d.Element(_versionAttributeName)?.Value) == result.Installed?.Version.ToString()
 				)
 			)
 			.ToArray();

src/LibYear.Core/ProjectFileManager.cs

@@ -81,9 +81,7 @@ public async Task<IReadOnlyCollection<string>> Update(SolutionResult result)
 		{
 			var update = project.ProjectFile.Update(project.Details);
 
-			var stream = _fileSystem.FileStream.New(project.ProjectFile.FileName, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None);
-			await new StreamWriter(stream).WriteAsync(update);
-			stream.Close();
+			await _fileSystem.File.WriteAllTextAsync(project.ProjectFile.FileName, update);
 			updated.Add(project.ProjectFile.FileName);
 		}
 

test/LibYear.Core.Tests/FileTypes/CsProjFileTests.cs

@@ -56,6 +56,56 @@ public async Task CanUpdateCsProjFile()
 		Assert.Equal(WildcardType.Major, newFile.Packages["test7"]!.WildcardType);
 	}
 
+	[Fact]
+	public async Task UpdateMaintainsIndent()
+	{
+		//arrange
+		var filename = Path.Combine("FileTypes", "project.csproj");
+		var original = await File.ReadAllTextAsync(filename);
+		var file = new CsProjFile(filename, original);
+		var results = Array.Empty<Result>();
+
+		//act
+		var updated = file.Update(results);
+
+		//assert
+		Assert.Equal(updated, original);
+	}
+
+	[Fact]
+	public async Task UpdateMaintainsFourSpaces()
+	{
+		//arrange
+		var filename = Path.Combine("FileTypes", "project.csproj");
+		var original = await File.ReadAllTextAsync(filename);
+		original = original.Replace("  ", "    ");
+		var file = new CsProjFile(filename, original);
+		var results = Array.Empty<Result>();
+
+		//act
+		var updated = file.Update(results);
+
+		//assert
+		Assert.Equal(updated, original);
+	}
+
+	[Fact]
+	public async Task UpdateMaintainsTabs()
+	{
+		//arrange
+		var filename = Path.Combine("FileTypes", "project.csproj");
+		var original = await File.ReadAllTextAsync(filename);
+		original = original.Replace("  ", "\t");
+		var file = new CsProjFile(filename, original);
+		var results = Array.Empty<Result>();
+
+		//act
+		var updated = file.Update(results);
+
+		//assert
+		Assert.Equal(updated, original);
+	}
+
 	[Fact]
 	public async Task InvalidVersionShowsExceptionDetails()
 	{