Moving existing csproj files with same name as migration output to backup

src/Microsoft.DotNet.ProjectJsonMigration/MigrationBackupPlan.cs

@@ -11,6 +11,8 @@ namespace Microsoft.DotNet.ProjectJsonMigration
 {
     internal class MigrationBackupPlan
     {
+        private const string TempCsprojExtention = ".migration_in_place_backup";
+
         private readonly FileInfo globalJson;
 
         public MigrationBackupPlan(
@@ -57,7 +59,8 @@ namespace Microsoft.DotNet.ProjectJsonMigration
                .Where(f => f.Name == "project.json"
                         || f.Extension == ".xproj"
                         || f.FullName.EndsWith(".xproj.user")
-                        || f.FullName.EndsWith(".lock.json"));
+                        || f.FullName.EndsWith(".lock.json")
+                        || f.FullName.EndsWith(TempCsprojExtention));
         }
 
         public DirectoryInfo ProjectBackupDirectory { get; }
@@ -81,10 +84,23 @@ namespace Microsoft.DotNet.ProjectJsonMigration
 
             foreach (var file in FilesToMove)
             {
+                var fileName = file.Name.EndsWith(TempCsprojExtention)
+                    ? Path.GetFileNameWithoutExtension(file.Name)
+                    : file.Name;
+
                 file.MoveTo(
-                    Path.Combine(
+                    Path.Combine(ProjectBackupDirectory.FullName, fileName));
-                        ProjectBackupDirectory.FullName, file.Name));
             }
         }
+
+        public static void RenameCsprojFromMigrationOutputNameToTempName(string outputProject)
+        {
+            var backupFileName = $"{outputProject}{TempCsprojExtention}";
+            if (File.Exists(backupFileName))
+            {
+                File.Delete(backupFileName);
+            }
+            File.Move(outputProject, backupFileName);
+        }
     }
 }

src/Microsoft.DotNet.ProjectJsonMigration/ProjectMigrator.cs

@@ -20,6 +20,7 @@ namespace Microsoft.DotNet.ProjectJsonMigration
     {
         private readonly IMigrationRule _ruleSet;
         private readonly ProjectDependencyFinder _projectDependencyFinder = new ProjectDependencyFinder();
+        private HashSet<string> _migratedProjects = new HashSet<string>();
 
         public ProjectMigrator() : this(new DefaultMigrationRuleSet()) { }
 
@@ -76,7 +77,6 @@ namespace Microsoft.DotNet.ProjectJsonMigration
                 var settings = new MigrationSettings(projectDir,
                                                      projectDir,
                                                      rootSettings.MSBuildProjectTemplatePath);
-                MigrateProject(settings);
                 projectMigrationReports.Add(MigrateProject(settings));
             }
 
@@ -141,13 +141,28 @@ namespace Microsoft.DotNet.ProjectJsonMigration
         {
             var migrationRuleInputs = ComputeMigrationRuleInputs(migrationSettings);
             var projectName = migrationRuleInputs.DefaultProjectContext.GetProjectName();
+            var outputProject = Path.Combine(migrationSettings.OutputDirectory, projectName + ".csproj");
 
             try
             {
-                if (IsMigrated(migrationSettings, migrationRuleInputs))
+                if (File.Exists(outputProject))
                 {
-                    MigrationTrace.Instance.WriteLine(String.Format(LocalizableStrings.SkipMigrationAlreadyMigrated, nameof(ProjectMigrator), migrationSettings.ProjectDirectory));
+                    if (_migratedProjects.Contains(outputProject))
-                    return new ProjectMigrationReport(migrationSettings.ProjectDirectory, projectName, skipped: true);
+                    {
+                        MigrationTrace.Instance.WriteLine(String.Format(
+                            LocalizableStrings.SkipMigrationAlreadyMigrated,
+                            nameof(ProjectMigrator),
+                            migrationSettings.ProjectDirectory));
+
+                        return new ProjectMigrationReport(
+                            migrationSettings.ProjectDirectory,
+                            projectName,
+                            skipped: true);
+                    }
+                    else
+                    {
+                        MigrationBackupPlan.RenameCsprojFromMigrationOutputNameToTempName(outputProject);
+                    }
                 }
 
                 VerifyInputs(migrationRuleInputs, migrationSettings);
@@ -185,7 +200,8 @@ namespace Microsoft.DotNet.ProjectJsonMigration
                 }
             }
 
-            var outputProject = Path.Combine(migrationSettings.OutputDirectory, projectName + ".csproj");
+            _migratedProjects.Add(outputProject);
+
             return new ProjectMigrationReport(
                 migrationSettings.ProjectDirectory,
                 projectName,
@@ -286,14 +302,5 @@ namespace Microsoft.DotNet.ProjectJsonMigration
                 File.Copy(sourceFilePath, destinationFilePath);
             }
         }
-
-        public bool IsMigrated(MigrationSettings migrationSettings, MigrationRuleInputs migrationRuleInputs)
-        {
-            var outputName = migrationRuleInputs.DefaultProjectContext.GetProjectName();
-
-            var outputProject = Path.Combine(migrationSettings.OutputDirectory, outputName + ".csproj");
-            return File.Exists(outputProject);
-        }
-
     }
 }

src/dotnet/commands/dotnet-migrate/MigrateCommand.cs

@@ -119,17 +119,17 @@ namespace Microsoft.DotNet.Tools.Migrate
             foreach (var report in migrationReport.ProjectMigrationReports)
             {
                 var reportPathWithTrailingSlash = PathUtility.EnsureTrailingSlash(report.ProjectDirectory);
-                var relReportPath = PathUtility.GetRelativePath(
+                var relativeReportPath = PathUtility.GetRelativePath(
                     slnPathWithTrailingSlash,
                     reportPathWithTrailingSlash);
 
-                var xprojPath = Path.Combine(relReportPath, report.ProjectName + ".xproj");
+                var xprojPath = Path.Combine(relativeReportPath, report.ProjectName + ".xproj");
-                var projects = _slnFile.Projects.Where(p => p.FilePath == xprojPath);
+                var xprojProjectsReferencedBySolution = _slnFile.Projects.Where(p => p.FilePath == xprojPath);
 
                 var migratedProjectName = report.ProjectName + ".csproj";
-                if (projects.Count() == 1)
+                if (xprojProjectsReferencedBySolution.Count() == 1)
                 {
-                    var slnProject = projects.Single();
+                    var slnProject = xprojProjectsReferencedBySolution.Single();
                     slnProject.FilePath = Path.Combine(
                         Path.GetDirectoryName(slnProject.FilePath),
                         migratedProjectName);
@@ -137,12 +137,12 @@ namespace Microsoft.DotNet.Tools.Migrate
                 }
                 else
                 {
-                    var csprojPath = Path.Combine(relReportPath, migratedProjectName);
+                    var csprojPath = Path.Combine(relativeReportPath, migratedProjectName);
-                    var slnAlreadyContainsMigratedCsproj = _slnFile.Projects
+                    var solutionContainsCsprojPriorToMigration = _slnFile.Projects
                         .Where(p => p.FilePath == csprojPath)
                         .Any();
 
-                    if (!slnAlreadyContainsMigratedCsproj)
+                    if (!solutionContainsCsprojPriorToMigration)
                     {
                         csprojFilesToAdd.Add(Path.Combine(report.ProjectDirectory, migratedProjectName));
                     }
@@ -299,7 +299,6 @@ namespace Microsoft.DotNet.Tools.Migrate
 
             if (projectMigrationReport.Errors.Any())
             {
-
                 sb.AppendLine(RedIfColored($"Project {projectMigrationReport.ProjectName} migration failed ({projectMigrationReport.ProjectDirectory})"));
 
                 foreach (var error in projectMigrationReport.Errors.Select(e => e.GetFormattedErrorMessage()))

test/dotnet-migrate.Tests/GivenThatIWantToMigrateSolutions.cs

@@ -67,6 +67,30 @@ namespace Microsoft.DotNet.Migration.Tests
                 "PJAppWithSlnAndXprojRefThatRefsCsprojWhereSlnDoesNotRefCsproj");
         }
 
+        [Fact]
+        public void WhenSolutionContainsACsprojFileItGetsMovedToBackup()
+        {
+            var projectDirectory = TestAssets
+                .Get("NonRestoredTestProjects", "PJAppWithSlnAndOneAlreadyMigratedCsproj")
+                .CreateInstance()
+                .WithSourceFiles()
+                .Root
+                .FullName;
+
+            var solutionRelPath = Path.Combine("TestApp", "TestApp.sln");
+            var cmd = new DotnetCommand()
+                .WithWorkingDirectory(projectDirectory)
+                .ExecuteWithCapturedOutput($"migrate \"{solutionRelPath}\"");
+            cmd.Should().Pass();
+
+            File.Exists(Path.Combine(projectDirectory, "TestLibrary", "TestLibrary.csproj"))
+                .Should().BeTrue();
+            File.Exists(Path.Combine(projectDirectory, "TestLibrary", "TestLibrary.csproj.migration_in_place_backup"))
+                .Should().BeFalse();
+            File.Exists(Path.Combine(projectDirectory, "backup", "TestLibrary", "TestLibrary.csproj"))
+                .Should().BeTrue();
+        }
+
         [Fact]
         public void WhenSolutionContainsACsprojFileItDoesNotTryToAddItAgain()
         {