Implement branch renames

Author: jnm2

src/TfvcMigrator/Program.cs

@@ -483,7 +483,7 @@ private static async IAsyncEnumerable<MappingState> EnumerateMappingStatesAsync(
                             var mapping = branchMappings[branch.SourceBranch];
 
                             mapping = PathUtils.IsOrContains(branch.SourceBranchPath, mapping.RootDirectory)
-                                ? mapping.RenameRootDirectory(branch.SourceBranchPath, branch.NewBranch.Path)
+                                ? mapping.ApplyRename(branch.SourceBranchPath, branch.NewBranch.Path)
                                 : mapping.WithSubdirectoryMapping(branch.NewBranch.Path, branch.SourceBranchPath);
 
                             branchMappings.Add(branch.NewBranch, mapping);
@@ -505,7 +505,13 @@ private static async IAsyncEnumerable<MappingState> EnumerateMappingStatesAsync(
                         case RenameOperation rename:
                         {
                             if (!branchMappings.Remove(rename.OldIdentity, out var mapping)) throw new NotImplementedException();
-                            branchMappings.Add(rename.NewIdentity, mapping.RenameRootDirectory(rename.OldIdentity.Path, rename.NewIdentity.Path));
+
+                            foreach (var (otherBranch, otherMapping) in branchMappings.ToArray())
+                            {
+                                branchMappings[otherBranch] = otherMapping.ApplyRename(rename.OldIdentity.Path, rename.NewIdentity.Path);
+                            }
+
+                            branchMappings.Add(rename.NewIdentity, mapping.ApplyRename(rename.OldIdentity.Path, rename.NewIdentity.Path));
 
                             if (trunk == rename.OldIdentity) trunk = rename.NewIdentity;
                             break;

src/TfvcMigrator/RepositoryBranchMapping.cs

@@ -42,23 +42,19 @@ public RepositoryBranchMapping(string rootDirectory, (string BranchDirectory, st
     /// </summary>
     public (string BranchDirectory, string TargetDirectory)? SubdirectoryMapping { get; }
 
-    public RepositoryBranchMapping RenameRootDirectory(string oldPath, string newPath)
+    public RepositoryBranchMapping ApplyRename(string oldPath, string newPath)
     {
         if (!PathUtils.IsAbsolute(oldPath))
             throw new ArgumentException("Old path must be absolute.", nameof(oldPath));
 
         if (!PathUtils.IsAbsolute(newPath))
             throw new ArgumentException("New path must be absolute.", nameof(newPath));
 
-        if (!PathUtils.IsOrContains(RootDirectory, oldPath))
-            throw new InvalidOperationException("The rename does not apply to this mapping.");
-
-        if (SubdirectoryMapping is not null)
-            throw new NotImplementedException("Research: Renaming and branching might behave differently when subdirectory mapping is involved.");
-
         return new RepositoryBranchMapping(
             PathUtils.ReplaceContainingPath(RootDirectory, oldPath, newPath),
-            subdirectoryMapping: null);
+            SubdirectoryMapping is null ? null : (
+                PathUtils.ReplaceContainingPath(SubdirectoryMapping.Value.BranchDirectory, oldPath, newPath),
+                PathUtils.ReplaceContainingPath(SubdirectoryMapping.Value.TargetDirectory, oldPath, newPath)));
     }
 
     public RepositoryBranchMapping WithSubdirectoryMapping(string branchDirectory, string targetDirectory)