Add a shareable pre-commit hook

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -0,0 +1,8 @@
+# direnv cache
+/.direnv
+
+# "nix build" default output link
+result
+
+# nix pre-commit autogenerated by devShell
+/.pre-commit-config.yaml

flake.lock

@@ -0,0 +1,102 @@
+{
+  "nodes": {
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1767039857,
+        "narHash": "sha256-vNpUSpF5Nuw8xvDLj2KCwwksIbjua2LZCqhV1LNRDns=",
+        "owner": "NixOS",
+        "repo": "flake-compat",
+        "rev": "5edf11c44bc78a0d334f6334cdaf7d60d732daab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "git-hooks": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1774104215,
+        "narHash": "sha256-EAtviqz0sEAxdHS4crqu7JGR5oI3BwaqG0mw7CmXkO8=",
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "f799ae951fde0627157f40aec28dec27b22076d0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "git-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1709087332,
+        "narHash": "sha256-HG2cCnktfHsKV0s4XW83gU3F57gaTljL9KNSuG6bnQs=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1774623183,
+        "narHash": "sha256-Oi8z/LMdeGaBBhe1v4P3wRcwbfJjjq1hjpF5EVgnxyA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "73e3cc5c77627ac9037a197e196ae88f5b209121",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "git-hooks": "git-hooks",
+        "nixpkgs": "nixpkgs",
+        "systems": "systems"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -1,11 +1,54 @@
 {
   description = "Shared Nix settings (NixOS, Home Manager etc)";
 
-  outputs = { self }: {
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs";
+    systems.url = "github:nix-systems/default";
+    git-hooks = {
+      url = "github:cachix/git-hooks.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      systems,
+      git-hooks,
+      ...
+    }:
+    let
+      eachSystem = nixpkgs.lib.genAttrs (import systems);
+    in
+    {
       nixosModules = {
         nix-settings = import ./modules/nix-settings.nix;
         nix-gc = import ./modules/nix-gc.nix;
         futureware = import ./modules/futureware.nix;
       };
+
+      lib.pre-commit = import ./pre-commit.nix;
+
+      checks = eachSystem (system: {
+        pre-commit-check = git-hooks.lib.${system}.run {
+          src = ./.;
+          inherit (self.lib.pre-commit) hooks;
+        };
+      });
+
+      devShells = eachSystem (
+        system:
+        let
+          pkgs = import nixpkgs { inherit system; };
+          inherit (self.checks.${system}.pre-commit-check) shellHook enabledPackages;
+        in
+        {
+          default = pkgs.mkShell {
+            packages = enabledPackages;
+            inherit shellHook;
+          };
+        }
+      );
     };
 }

pre-commit.nix

@@ -0,0 +1,21 @@
+{
+  hooks = {
+    check-added-large-files.enable = true;
+    check-case-conflicts.enable = true;
+    check-executables-have-shebangs.enable = true;
+    check-merge-conflicts.enable = true;
+    check-symlinks.enable = true;
+    check-vcs-permalinks.enable = true;
+    check-yaml.enable = true;
+    end-of-file-fixer.enable = true;
+    trim-trailing-whitespace.enable = true;
+    ripsecrets.enable = true;
+
+    # Nix
+    flake-checker.enable = true;
+    nixfmt-rfc-style.enable = true;
+    deadnix.enable = true;
+    nil.enable = true;
+    statix.enable = true; # Use: statix fix
+  };
+}