diffsitter

Summary

diffsitter performs diffs on text files using the AST to compute the diff instead of using a naive text-based diff. This can give you more semantically meaningful diff information, which will prevent diffs from getting polluted by formatting differences, for example.

diffstter uses the parsers from the tree-sitter project to parse source code. As such, the languages supported by this tool are limited by the languages supported by the tree-sitter project.

Examples

Take the following files:

a.rs:

fn main() {
    let x = 1;
}

b.rs

fn



main

()

{
}

fn addition() {
}

fn add_two() {
}

The standard output from diff will get you:

1,2c1,12
< fn main() {
<     let x = 1;
---
> fn
>
>
>
> main
>
> ()
>
> {
> }
>
> fn addition() {
5c15
< fn add_one {
---
> fn add_two() {

You can see that it picks up the formatting differences for the main function, even though they aren't semantically different.

Check out the output from diffsitter:

-     let x = 1;
- fn add_one {
+ }
+ fn addition() {
+ fn add_two() {

Since it uses the AST to calculate the difference, it knows that the formatting differences in main between the two files isn't a meaningful difference, so it doesn't show up in the diff.

diffsitter has some nice (terminal aware) formatting too:

Installation

Published binaries

This project uses Github actions to build and publish binaries for each tagged release. You can download binaries from there if your platform is listed.

Cargo

You can install using cargo the standard way with cargo install diffsitter.

Homebrew

You can use my tap to install diffsitter:

brew tap afnanenayet/tap
brew install diffsitter
# brew install afnanenayet/tap/diffsitter

Usage

For detailed help you can run diffsitter --help (diffsitter -h provides brief help messages).

You can configure file associations and formatting options for diffsitter using a config file. If a config is not supplied, the app will use the default config, which you can see with diffsitter --cmd dump_default_config. It will look for a config at $XDG_HOME/.config on macOS and Linux, and the standard directory for Windows. You can also refer to the sample config.

Note: the tests for this crate check to make sure the provided sample config is a valid config.

Development

In order to develop for this project, you need to clone the project and initialize all submodules (each tree-sitter grammar is added as a subdirectory).

git clone
git submodule --init --recursive

This uses cargo with the cc crate, so you need to install rust and have a working C and C++ compiler.

This project targets the latest stable version of rustc, it may work on older versions, but I only guarantee support for the latest stable release.