[!CAUTION]

1. This project is now hosted at tangled.
2. A significant fork by Molybdenum Software exists.
3. The source for the Nixpkgs statix package is the Molybdenum Software fork
4. The maintainer of the Molybdenum Software fork is eager to merge back.

#statix

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.).

#Examples

$ 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

#Installation

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

Install from nixpkgs:

nix run nixpkgs#statix -- help

Install with brew/linuxbrew

brew install statix

#Usage

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

# ignore more than one file
statix check /path/to/dir -i a.nix b.nix c.nix

# ignore an entire directory
statix check /path/to/dir -i .direnv

# statix respects your .gitignore if it exists
# run statix in "unrestricted" mode, to disable that
statix check /path/to/dir -u

# 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

#Configuration

Ignore lints and fixes by creating a statix.toml file at your project root:

# within statix.toml
disabled = [
  "empty_pattern"
]

statix automatically discovers the configuration file by traversing parents of the current directory and looking for a statix.toml file. Alternatively, you can pass the path to the statix.toml file on the command line with the --config flag (available on statix check and statix fix).

The available lints are (see statix list for an updated list):

bool_comparison
empty_let_in
manual_inherit
manual_inherit_from
legacy_let_syntax
collapsible_let_in
eta_reduction
useless_parens
empty_pattern
redundant_pattern_bind
unquoted_uri
empty_inherit
deprecated_to_path
bool_simplification
useless_has_attr

All lints are enabled by default. Generate a minimal config with statix dump > statix.toml.