I can’t believe (g)it’s not a file!

a Visual Studio Code extension to directly edit what’s staged in git

Have you ever opened up a git diff of a file and wished "It would be really nice if I could directly edit the left side of the diff"?

Perhaps, were you a Vim user and you miss this functionality that the vim-fugitive plugin supports?

Although, yes, git add already has a --patch flag for staging smaller blocks of the file and edit the patches, and yes, you can do stage individual blocks in VSCode as well. However, none of these are as powerful and as elegant as treating the staged version of the file as an editable file, where you can see the full file context and benefit from most of the existing features of your editor.

Install

You can find this extension in the following places:

• Visual Studio Marketplace: https://marketplace.visualstudio.com/items?itemName=ErnWong.icantbelievegit

• Open VSX Registry: https://open-vsx.org/extension/ErnWong/icantbelievegit

• You can also download the latest pre-release .vsix file and install it manually (Extensions -> Views and More Actions... -> Install from VSIX...) or via command line:

  code --install-extension icantbelievegit-0.0.1.vsix
  

• Nix flakes via Home Manager

  # In your flake.nix file
  inputs.icantbelievegit = {
    url = "github:ErnWong/i-cant-believe-gits-not-a-file";
    inputs.nixpkgs.follows = "nixpkgs";
  };
  
  # ... later in your home manager config:
  programs.vscode = {
    enable = true;
    profiles.default.extensions = [
      icantbelievegit.packages.${system}.default
    ];
  };
  

Usage

But, why? Here are some usecases

I personally use this feature of vim-fugitive all the time. Here are some typical situations I end up in where I find this useful.

• I regularly have a lot of local temporary changes that are only there to help debugging. E.g. extra logging, etc. These changes may be intertwined with legitimate changes I wish to commit.
• I may try to do a full rough prototype of some larger changes first, before going back and commiting the changes as a series of piecemeal/incremental commits.

In these cases, git add -p and friends would not be able to provide the level of granularity and ease of editing what I want to commit, and oftentimes I would reach outside of VS Code and open up Vim just so I can make the change I want.

Disclaimer: Not fully tested

The following areas haven't been looked at nor tested:

• Windows support
• Using this extension during a merge conflict resolution
• File mode changes
• Git clean/smudge filters
• Line-ending handling
• Remote files - only local files supported at the moment.
• Watching the index for changes and automatically updating the editor.

How it works

Using Git Plumbing commands, we have all the tools needed to:

1. Read the objects (git cat-file) pointed to by the index (git ls-files --cached) so we can present it to the user as a virtual file.
2. Generate our own objects (git hash-object -w) when the user saves our virtual file.
3. Update the index with our new object (git update-index).

Inspiration Credits

Thank you to Tim Pope's legendary fugitive vim plugin from which I discovered this feature, and from which led me to appreciate how git works.

Thank you to bers for asking this question on Stack Overflow: https://stackoverflow.com/questions/62810963/why-cant-i-directly-edit-staged-changes-in-the-git-index-with-vs-code which motivated me to go ahead and make this extension.

Do you have a VS Code extension that does something similar? Or perhaps a different tool or a different plugin for a different editor? I'd love to know! Feel free to raise an issue or a PR and I'd be happy to include it here.