Add pre-commit hooks for formatting and dead code

.gitignore

@@ -6,3 +6,4 @@ result*
 output
 todo
 
+/.pre-commit-config.yaml

flake.lock

@@ -18,6 +18,64 @@
         "type": "github"
       }
     },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1696426674,
+        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "git-hooks": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "gitignore": "gitignore",
+        "nixpkgs": "nixpkgs_2",
+        "nixpkgs-stable": "nixpkgs-stable"
+      },
+      "locked": {
+        "lastModified": 1730814269,
+        "narHash": "sha256-fWPHyhYE6xvMI1eGY3pwBTq85wcy1YXqdzTZF+06nOg=",
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "d70155fdc00df4628446352fc58adc640cd705c2",
+        "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": 1725194671,
@@ -49,7 +107,39 @@
         "type": "github"
       }
     },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1730741070,
+        "narHash": "sha256-edm8WG19kWozJ/GqyYx2VjW99EdhjKwbY3ZwdlPAAlo=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d063c1dd113c91ab27959ba540c0d9753409edf3",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-24.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1730768919,
+        "narHash": "sha256-8AKquNnnSaJRXZxc5YmF/WfmxiHX6MMZZasRP6RRQkE=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "a04d33c0c3f1a59a2c1cb0c6e34cd24500e5a1dc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_3": {
       "locked": {
         "lastModified": 1730137230,
         "narHash": "sha256-0kW6v0alzWIc/Dc/DoVZ7A9qNScv77bj/zYTKI67HZM=",
@@ -85,7 +175,8 @@
     "root": {
       "inputs": {
         "disko": "disko",
-        "nixpkgs": "nixpkgs_2",
+        "git-hooks": "git-hooks",
+        "nixpkgs": "nixpkgs_3",
         "nixpkgs-latest": "nixpkgs-latest",
         "pixelfed": "pixelfed"
       }

flake.nix

@@ -2,6 +2,8 @@
   inputs = {
     nixpkgs.url = "github:radvendii/nixpkgs/nixos_rebuild_tests";
     nixpkgs-latest.url = "github:nixos/nixpkgs";
+    git-hooks.url = "github:cachix/git-hooks.nix";
+
     pixelfed = {
       url = "github:pixelfed/pixelfed?ref=v0.12.3";
       flake = false;
@@ -14,6 +16,7 @@
       self,
       nixpkgs,
       nixpkgs-latest,
+      git-hooks,
       pixelfed,
       disko,
     }:
@@ -120,12 +123,21 @@
       checks.${system} = {
         mastodon-garage = import ./tests/mastodon-garage.nix { inherit pkgs self; };
         pixelfed-garage = import ./tests/pixelfed-garage.nix { inherit pkgs self; };
+
+        pre-commit = git-hooks.lib.${system}.run {
+          src = ./.;
+          hooks = {
+            nixfmt-rfc-style.enable = true;
+            deadnix.enable = true;
+          };
+        };
       };
 
       devShells.${system}.default = pkgs.mkShell {
         inputs = with pkgs; [
           nil
         ];
+        shellHook = self.checks.${system}.pre-commit.shellHook;
       };
     };
 }