Folders and files

Name		Name	Last commit message	Last commit date
Latest commit History 299 Commits
.github		.github
src		src
.gitignore		.gitignore
.pre-commit-hooks.yaml		.pre-commit-hooks.yaml
Cargo.lock		Cargo.lock
Cargo.toml		Cargo.toml
LICENSE		LICENSE
README.md		README.md
example.nix		example.nix
flake.lock		flake.lock
flake.nix		flake.nix

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deadnix

Scan.nix files for dead code (unused variable bindings).

Usage with Github Actions

Seedeadnix-action

Usage with Nix Flakes

Help

nix run github:astro/deadnix -- --helpFind dead code in .nix filesUsage: deadnix [OPTIONS] [FILE_PATHS]...Arguments:  [FILE_PATHS]...  .nix files, or directories with .nix files inside [default: .]Options:  -l, --no-lambda-arg                  Don't check lambda parameter arguments  -L, --no-lambda-pattern-names        Don't check lambda attrset pattern names (don't break nixpkgs callPackage)  -_, --no-underscore                  Don't check any bindings that start with a _  -q, --quiet                          Don't print dead code report  -e, --edit                           Remove unused code and write to source file  -h, --hidden                         Recurse into hidden subdirectories and process hidden .*.nix files      --help  -f, --fail                           Exit with 1 if unused code has been found  -o, --output-format <OUTPUT_FORMAT>  Output format to use [default: human-readable] [possible values: human-readable, json]      --exclude <EXCLUDES>...          Files to exclude from analysis  -V, --version                        Print version

Reports contain ANSI color escape codes unless the$NO_COLOR environment variable is set.

The--exclude parameter accepts multiple paths. Separate them with-- to pass[FILE_PATHS]....

Scan for unused code

nix run github:astro/deadnix example.nixWarning: Unused declarations were found.    ╭─[example.nix:1:1]  1 │unusedArgs@{ unusedArg, usedArg, ... }:    ·     │           ╰───── Unused lambda pattern: unusedArg    ·     ╰───────────────── Unused lambda pattern: unusedArgs  3 │  inherit (builtins) unused_inherit;    ·                            ╰─────── Unused let binding: unused_inherit  5 │  unused = "fnord";    ·     ╰─── Unused let binding: unused 10 │  shadowed = 42;    ·      ╰──── Unused let binding: shadowed 11 │  _unused = unused: false;    ·     │         ╰─── Unused lambda argument: unused    ·     ╰───────────── Unused let binding: _unused 13 │  x = { unusedArg2, x ? args.y, ... }@args: used1 + x;    ·             ╰───── Unused lambda pattern: unusedArg2

Remove unused code automatically

Do commit your changes into version controlbefore!

nix run github:astro/deadnix -- -eq test.nix

Usage withpre-commit

Add the following to your project's.pre-commit-config.yaml:

repos:  -repo:https://github.com/astro/deadnixrev:ID# frozen: VERSIONhooks:      -id:deadnix#args: [--edit] # Uncomment to automatically modify filesstages:[commit]

ReplaceID andVERSION above with the relevant version tag andcommit ID for reference, for example:

rev:da39a3ee5e6b4b0d3255bfef95601890afd80709# frozen: v1.2.3

Behavior

Renaming of all unused to lambda args to start with`_`

If you disfavor marking them as unused, use option-l/--no-lambda-arg.

nixpkgs`callPackages` with multiple imports

callPackages guesses the packages to inject by the names of apackages' lambda attrset pattern names. Some packages alias these with@args to pass them to anotherimport ...nix args.

As the used args are only named in the imported file they will berecognized as dead in the package source file that is imported bycallPackage, rendering it unable to guess the dependencies to callthe packages with.

Use option-L/--no-lambda-pattern-names in this case.