Lints and suggestions for the Nix programming language.

statix check highlights antipatterns in Nix code. statix fix can fix several such occurrences.

For the time-being, statix works only with ASTs produced by the rnix-parser crate and does not evaluate any nix code (imports, attr sets etc.).

$ statix check tests/c.nix
[W04] Warning: Assignment instead of inherit from
   ╭─[tests/c.nix:2:3]
   │
 2 │   mtl = pkgs.haskellPackages.mtl;
   ·   ───────────────┬───────────────
   ·                  ╰───────────────── This assignment is better written with inherit
───╯

$ statix fix --dry-run tests/c.nix
--- tests/c.nix
+++ tests/c.nix [fixed]
@@ -1,6 +1,6 @@
 let
-  mtl = pkgs.haskellPackages.mtl;
+  inherit (pkgs.haskellPackages) mtl;
 in
 null

statix is available via a nix flake:

# build from source
nix build git+https://git.peppe.rs/languages/statix
./result/bin/statix --help

# statix also provides a flake app
nix run git+https://git.peppe.rs/languages/statix -- --help

# save time on builds using cachix
cachix use statix

Basic usage is as simple as:

# recursively finds nix files and raises lints
statix check /path/to/dir

# ignore generated files, such as Cargo.nix
statix check /path/to/dir -i '*Cargo.nix'

# see `statix -h` for a full list of options

Certain lints have suggestions. Apply suggestions back to the source with:

statix fix /path/to/file

# show diff, do not write to file
statix fix --dry-run /path/to/file

statix supports a variety of output formats; standard, json and errfmt:

statix check /path/to/dir -o json   # only when compiled with --all-features
statix check /path/to/dir -o errfmt # singleline, easy to integrate with vim

statix has the following components:

• bin: the CLI/entrypoint
• lib: library of lints and utilities to define these lints
• vfs: virtual filesystem
• macros: procedural macros to help define a lint

This is the main point of interaction between statix and the end user. It's output is human-readable and should also support JSON/errorfmt outputs for external tools to use.

A library of AST-based lints and utilities to help write those lints. It should be easy for newcomers to write lints without being familiar with the rest of the codebase.

VFS is an in-memory filesystem. It provides cheap-to-copy handles (FileIds) to access paths and file contents.

This crate intends to be a helper layer to declare lints and their metadata.

• Offline documentation for each lint
• Test suite for lints and suggestions
• Vim plugin (qf list population, apply suggestions)
• Resolve imports and scopes for better lints
• Add silent flag that exits with status