Emit warning for projects detected in multiple drives

src/Microsoft.VisualStudio.SlnGen.UnitTests/SlnFileTests.cs

@@ -10,6 +10,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text;
 using Xunit;
 
 namespace Microsoft.VisualStudio.SlnGen.UnitTests
@@ -106,7 +107,7 @@ public void CustomConfigurationAndPlatforms()
 
             string solutionFilePath = GetTempFileName();
 
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -193,7 +194,7 @@ public void CustomConfigurationAndPlatformsWithAlwaysBuildDisabled()
 
             string solutionFilePath = GetTempFileName();
 
-            slnFile.Save(solutionFilePath, useFolders: false, alwaysBuild: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger(), alwaysBuild: false);
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -232,7 +233,7 @@ public void CustomConfigurationAndPlatforms_IgnoresInvalidValues()
 
             string solutionFilePath = GetTempFileName();
 
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -314,7 +315,7 @@ public void CustomConfigurationAndPlatforms_MapsAnyCPU()
 
             string solutionFilePath = GetTempFileName();
 
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -354,7 +355,7 @@ public void ExistingSolutionIsReused()
 
             slnFile.AddProjects(new[] { project });
 
-            slnFile.Save(path, useFolders: false);
+            slnFile.Save(path, useFolders: false, new TestLogger());
 
             SlnFile.TryParseExistingSolution(path, out Guid solutionGuid, out _).ShouldBeTrue();
 
@@ -554,7 +555,7 @@ public void ProjectConfigurationPlatformOrderingSameAsProjects()
 
             string path = Path.GetTempFileName();
 
-            slnFile.Save(path, useFolders: false);
+            slnFile.Save(path, useFolders: false, new TestLogger());
 
             string directoryName = new DirectoryInfo(TestRootPath).Name;
 
@@ -636,7 +637,7 @@ public void ProjectSolutionFolders()
 
             slnFile.AddProjects(projects, new Dictionary<string, Guid>(), projects[1].FullPath);
             slnFile.AddSolutionItems(solutionItems);
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             SolutionFile s = SolutionFile.Parse(solutionFilePath);
 
@@ -672,7 +673,7 @@ public void SaveToCustomLocationCreatesDirectory()
 
             SlnFile slnFile = new SlnFile();
 
-            slnFile.Save(fullPath, useFolders: false);
+            slnFile.Save(fullPath, useFolders: false, new TestLogger());
 
             File.Exists(fullPath).ShouldBeTrue();
         }
@@ -891,7 +892,7 @@ public void WithFoldersDoNotIgnoreMainProject()
 
             slnFile.AddProjects(projects, new Dictionary<string, Guid>(), projects[1].FullPath);
             slnFile.AddSolutionItems(solutionItems);
-            slnFile.Save(solutionFilePath, true);
+            slnFile.Save(solutionFilePath, true, new TestLogger());
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -949,7 +950,7 @@ public void WithFoldersIgnoreMainProject()
 
             slnFile.AddProjects(projects, new Dictionary<string, Guid>());
             slnFile.AddSolutionItems(solutionItems);
-            slnFile.Save(solutionFilePath, true);
+            slnFile.Save(solutionFilePath, true, new TestLogger());
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -1016,7 +1017,7 @@ public void WithFoldersDoesNotCreateRootFolder(bool ignoreMainProject, bool coll
 
             slnFile.AddProjects(projects, new Dictionary<string, Guid>(), ignoreMainProject ? null : projects[1].FullPath);
             slnFile.AddSolutionItems(solutionItems);
-            slnFile.Save(solutionFilePath, useFolders: true, collapseFolders: collapseFolders);
+            slnFile.Save(solutionFilePath, useFolders: true, new TestLogger(), collapseFolders: collapseFolders);
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 
@@ -1072,7 +1073,7 @@ public void VisualStudioVersionIsWritten()
                 SolutionGuid = new Guid("{6370DE27-36B7-44AE-B47A-1ECF4A6D740A}"),
             };
 
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             File.ReadAllText(solutionFilePath).ShouldBe(
                 @"Microsoft Visual Studio Solution File, Format Version 12.00
@@ -1109,7 +1110,7 @@ public void Save_WithSolutionItemsAddedToSpecificFolder_SolutionItemsExistInSpec
             slnFile.AddSolutionItems("docs", new[] { Path.Combine(this.TestRootPath, "README.md") });
 
             // Act
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             // Assert
             File.ReadAllText(solutionFilePath).ShouldBe(
@@ -1135,6 +1136,48 @@ public void Save_WithSolutionItemsAddedToSpecificFolder_SolutionItemsExistInSpec
                 StringCompareShould.IgnoreLineEndings);
         }
 
+        [Fact]
+        public void EmitWarningForProjectsOnMultipleDrives()
+        {
+            bool isWindowsPlatform = Utility.RunningOnWindows;
+            SlnProject projectA = new ()
+            {
+                Name = "ProjectA",
+                FullPath = isWindowsPlatform ? @"A:\ProjectA\ProjectA.vcxitems" : "/dev/ProjectA/ProjectA.vcxitems",
+                ProjectGuid = new Guid("C95D800E-F016-4167-8E1B-1D3FF94CE2E2"),
+                ProjectTypeGuid = new Guid("88152E7E-47E3-45C8-B5D3-DDB15B2F0435"),
+            };
+
+            SlnProject projectB = new ()
+            {
+                Name = "ProjectB",
+                FullPath = isWindowsPlatform ? @"B:\ProjectB\ProjectB.vcxitems" : "/mnt/ProjectB/ProjectB.vcxitems",
+                ProjectGuid = new Guid("EAD108BE-AC70-41E6-A8C3-450C545FDC0E"),
+                ProjectTypeGuid = new Guid("F38341C3-343F-421A-AE68-94CD9ADCD32F"),
+            };
+
+            TestLogger logger = new ();
+            SlnFile slnFile = new ();
+            SlnProject[] projects = new[] { projectA, projectB };
+            string solutionFilePath = GetTempFileName();
+            StringBuilderTextWriter writer = new (new StringBuilder(), new List<string>());
+
+            slnFile.AddProjects(projects);
+            slnFile.Save(solutionFilePath, writer, useFolders: true, logger);
+
+            logger.Errors.Count.ShouldBe(0);
+
+            if (isWindowsPlatform)
+            {
+                logger.Warnings.Count.ShouldBe(1);
+                logger.Warnings.FirstOrDefault().Message.ShouldContain("Detected two or more projects on multiple drives");
+            }
+            else
+            {
+                logger.Warnings.Count.ShouldBe(0);
+            }
+        }
+
         [Theory]
         [InlineData(true)]
         [InlineData(false)]
@@ -1155,7 +1198,7 @@ public void SlnProject_IsBuildable_ReflectedAsProjectConfigurationInSolutionIncl
             };
 
             slnFile.AddProjects(new[] { slnProject });
-            slnFile.Save(solutionFilePath, useFolders: false);
+            slnFile.Save(solutionFilePath, useFolders: false, new TestLogger());
 
             ValidateProjectInSolution(
                 (slnProject, projectInSolution) =>
@@ -1178,7 +1221,7 @@ private void ValidateProjectInSolution(Action<SlnProject, ProjectInSolution> cus
             SlnFile slnFile = new SlnFile();
 
             slnFile.AddProjects(projects);
-            slnFile.Save(solutionFilePath, useFolders);
+            slnFile.Save(solutionFilePath, useFolders, new TestLogger());
 
             SolutionFile solutionFile = SolutionFile.Parse(solutionFilePath);
 

src/Microsoft.VisualStudio.SlnGen.UnitTests/StringBuilderTextWriter.cs

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft Corporation.
+//
+// Licensed under the MIT license.
+
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace Microsoft.VisualStudio.SlnGen.UnitTests
+{
+    /// <summary>
+    /// Extends <see cref="TextWriter" /> for unit tests to capture writing text.
+    /// </summary>
+    public class StringBuilderTextWriter : TextWriter
+    {
+        private readonly List<string> _lines;
+        private readonly StringBuilder _lineStringBuilder = new StringBuilder();
+        private readonly StringBuilder _stringBuilder;
+
+        public StringBuilderTextWriter(StringBuilder stringBuilder, List<string> lines)
+        {
+            _stringBuilder = stringBuilder;
+            _lines = lines;
+        }
+
+        public override Encoding Encoding => Encoding.Unicode;
+
+        public override void Write(char value)
+        {
+            _lineStringBuilder.Append(value);
+
+            _stringBuilder.Append(value);
+
+            if (value == '\n')
+            {
+                _lines.Add(_lineStringBuilder.ToString());
+
+                _lineStringBuilder.Clear();
+            }
+        }
+    }
+}

src/Microsoft.VisualStudio.SlnGen.UnitTests/TestConsole.cs

@@ -63,34 +63,5 @@ public event ConsoleCancelEventHandler CancelKeyPress
         public void ResetColor()
         {
         }
-
-        private class StringBuilderTextWriter : TextWriter
-        {
-            private readonly List<string> _lines;
-            private readonly StringBuilder _lineStringBuilder = new StringBuilder();
-            private readonly StringBuilder _stringBuilder;
-
-            public StringBuilderTextWriter(StringBuilder stringBuilder, List<string> lines)
-            {
-                _stringBuilder = stringBuilder;
-                _lines = lines;
-            }
-
-            public override Encoding Encoding => Encoding.Unicode;
-
-            public override void Write(char value)
-            {
-                _lineStringBuilder.Append(value);
-
-                _stringBuilder.Append(value);
-
-                if (value == '\n')
-                {
-                    _lines.Add(_lineStringBuilder.ToString());
-
-                    _lineStringBuilder.Clear();
-                }
-            }
-        }
     }
 }

src/Microsoft.VisualStudio.SlnGen/SlnFile.cs

@@ -213,7 +213,7 @@ public static (string solutionFileFullPath, int customProjectTypeGuidCount, int
 
             if (!logger.HasLoggedErrors)
             {
-                solution.Save(solutionFileFullPath, arguments.EnableFolders(), arguments.EnableCollapseFolders(), arguments.EnableAlwaysBuild());
+                solution.Save(solutionFileFullPath, arguments.EnableFolders(), logger, arguments.EnableCollapseFolders(), arguments.EnableAlwaysBuild());
             }
 
             return (solutionFileFullPath, customProjectTypeGuids.Count, solutionItems.Count, solution.SolutionGuid);
@@ -362,9 +362,10 @@ public void AddSolutionItems(string folderPath, IEnumerable<string> items)
         /// </summary>
         /// <param name="path">The full path to the file to write to.</param>
         /// <param name="useFolders">Specifies if folders should be created.</param>
+        /// <param name="logger">A <see cref="ISlnGenLogger" /> to use for logging.</param>
         /// <param name="collapseFolders">An optional value indicating whether or not folders containing a single item should be collapsed into their parent folder.</param>
         /// <param name="alwaysBuild">An optional value indicating whether or not to always include the project in the build even if it has no matching configuration.</param>
-        public void Save(string path, bool useFolders, bool collapseFolders = false, bool alwaysBuild = true)
+        public void Save(string path, bool useFolders, ISlnGenLogger logger, bool collapseFolders = false, bool alwaysBuild = true)
         {
             string directoryName = Path.GetDirectoryName(path);
 
@@ -377,7 +378,7 @@ public void Save(string path, bool useFolders, bool collapseFolders = false, boo
 
             using StreamWriter writer = new StreamWriter(fileStream, Encoding.UTF8);
 
-            Save(path, writer, useFolders, collapseFolders, alwaysBuild);
+            Save(path, writer, useFolders, logger, collapseFolders, alwaysBuild);
         }
 
         /// <summary>
@@ -386,9 +387,10 @@ public void Save(string path, bool useFolders, bool collapseFolders = false, boo
         /// <param name="rootPath">A root path for the solution to make other paths relative to.</param>
         /// <param name="writer">The <see cref="TextWriter" /> to save the solution file to.</param>
         /// <param name="useFolders">Specifies if folders should be created.</param>
+        /// <param name="logger">A <see cref="ISlnGenLogger" /> to use for logging.</param>
         /// <param name="collapseFolders">An optional value indicating whether or not folders containing a single item should be collapsed into their parent folder.</param>
         /// <param name="alwaysBuild">An optional value indicating whether or not to always include the project in the build even if it has no matching configuration.</param>
-        internal void Save(string rootPath, TextWriter writer, bool useFolders, bool collapseFolders = false, bool alwaysBuild = true)
+        internal void Save(string rootPath, TextWriter writer, bool useFolders, ISlnGenLogger logger, bool collapseFolders = false, bool alwaysBuild = true)
         {
             writer.WriteLine(Header, _fileFormatVersion);
 
@@ -441,9 +443,21 @@ internal void Save(string rootPath, TextWriter writer, bool useFolders, bool col
 
             if (hierarchy != null)
             {
+                HashSet<string> drives = new ();
                 foreach (SlnFolder folder in hierarchy.Folders)
                 {
-                    string projectSolutionPath = (useFolders ? folder.FullPath.ToRelativePath(rootPath) : folder.FullPath).ToSolutionPath();
+                    bool hasPathRoot = false;
+                    if (!string.IsNullOrEmpty(folder.FullPath))
+                    {
+                        string pathRoot = Path.GetPathRoot(folder.FullPath);
+                        hasPathRoot = !string.IsNullOrEmpty(pathRoot);
+                        if (hasPathRoot)
+                        {
+                            drives.Add(pathRoot);
+                        }
+                    }
+
+                    string projectSolutionPath = (useFolders && hasPathRoot ? folder.FullPath.ToRelativePath(rootPath) : folder.FullPath).ToSolutionPath();
 
                     // Try to preserve the folder GUID if a matching relative folder path was parsed from an existing solution
                     if (ExistingProjectGuids != null && ExistingProjectGuids.TryGetValue(projectSolutionPath, out Guid projectGuid))
@@ -470,6 +484,11 @@ internal void Save(string rootPath, TextWriter writer, bool useFolders, bool col
                         writer.WriteLine("EndProject");
                     }
                 }
+
+                if (drives.Count > 1)
+                {
+                    logger.LogWarning($"Detected two or more projects on multiple drives: {string.Join(", ", drives)}. These projects should not be committed to source control since they do not contain simple, relative paths and are not guaranteed to work across machines.");
+                }
             }
 
             writer.WriteLine("Global");

src/Microsoft.VisualStudio.SlnGen/SlnFolder.cs

@@ -35,7 +35,7 @@ public SlnFolder(string path)
         }
 
         /// <summary>
-        /// Gets the <see cref="Guid" /> of the folder.
+        /// Gets or sets the <see cref="Guid" /> of the folder.
         /// </summary>
         public Guid FolderGuid { get; set; }