feat: add nix for formatting

Also adds CI tests!

.editorconfig

@@ -0,0 +1,8 @@
+[*]
+end_of_line = lf
+charset = utf-8
+
+[*.{nix,json,sh}]
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true

.forgejo/workflows/check.yml

@@ -0,0 +1,41 @@
+on:
+  push:
+jobs:
+  check:
+    runs-on: nixos
+    strategy:
+      matrix:
+        check:
+          - treefmt
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - name: Run checks
+        run: |
+          nix --version
+          # shellcheck disable=SC2016
+          nix build --print-build-logs '.#checks.x86_64-linux.${{ matrix.check }}'
+  check-renovaterc:
+    runs-on: nixos
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - name: Validate renovaterc.json
+        run: |
+          nix --version
+          nix shell nixpkgs#renovate --command renovate-config-validator
+  report-size:
+    runs-on: nixos
+    needs: check
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - run: nix --version
+      - name: Create Size Report
+        uses: ./action.yml
+        with:
+          # Create a comment on the associated PR
+          comment-on-pr: ${{ github.ref_name != 'main' }}
+          # Generate artifacts on main (to speed up comparisons)
+          generate-artifact: ${{ github.ref_name == 'main' }}
+          # Generate comparisons to main
+          do-comparison: 'true'
+          # This job's name (so we can find the artifacts)
+          job-name: report-size

README.md

@@ -51,6 +51,7 @@ For more details see the [action.yaml](./action.yml) file.
   - Reduce the `NAR Size` by reducing the size of the build outputs, e.g. don't copy unnecessary data to the $out dir, optimize binaries for size, etc.
   - Reduce the `Size` by reducing the dependencies (e.g. `buildInputs`).
   - Don't worry too much about size, some dependencies are deduplicated, e.g. `glibc` adds ~40MiB to the `Size`, but is generally shared by ~every binary on the system, so, chances are, you are already including it from somewhere else and statically linking with e.g. `musl` is not gonna improve things.
+
 # NixOS Configurations
 
 | Name | Size | Size Change | NAR Size | NAR Size Change |

flake.lock

@@ -0,0 +1,98 @@
+{
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1741352980,
+        "narHash": "sha256-+u2UunDA4Cl5Fci3m7S643HzKmIDAe+fiXrLqYsR2fs=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "f4330d22f1c5d2ba72d3d22df5597d123fdb60a9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1741513245,
+        "narHash": "sha256-7rTAMNTY1xoBwz0h7ZMtEcd8LELk9R5TzBPoHuhNSCk=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e3e32b642a31e6714ec1b712de8c91a3352ce7e1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1740877520,
+        "narHash": "sha256-oiwv/ZK/2FhGxrCkQkB83i7GnWXPPLzoqFHpDD3uYpk=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "147dee35aab2193b174e4c0868bd80ead5ce755c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs",
+        "systems": "systems",
+        "treefmt-nix": "treefmt-nix"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1739829690,
+        "narHash": "sha256-mL1szCeIsjh6Khn3nH2cYtwO5YXG6gBiTw1A30iGeDU=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "3d0579f5cc93436052d94b73925b48973a104204",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,43 @@
+{
+  description = "Description for the project";
+
+  inputs = {
+    flake-parts.url = "github:hercules-ci/flake-parts";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    treefmt-nix = {
+      url = "github:numtide/treefmt-nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    systems.url = "github:nix-systems/default";
+  };
+
+  outputs =
+    inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [ inputs.treefmt-nix.flakeModule ];
+      systems = import inputs.systems;
+
+      perSystem =
+        { pkgs, ... }:
+        {
+          # Export pkgs.hello so we can test this action
+          packages = { inherit (pkgs) hello; };
+
+          # Setup formatters
+          treefmt = {
+            # Ignore images
+            settings.global.excludes = [ "*.png" ];
+            projectRootFile = "flake.nix";
+            programs = {
+              mdformat.enable = true;
+              nixfmt.enable = true;
+              shfmt.enable = true;
+              shellcheck.enable = true;
+              statix.enable = true;
+              typos.enable = true;
+              yamlfmt.enable = true;
+            };
+          };
+        };
+    };
+}

utils.sh

@@ -1,3 +1,5 @@
+#!/bin/sh
+
 log() {
   echo "$@" >&2
 }