From 37b3fc8b4fdf1e4225c31c41f7205108f5f4bf6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Silas=20Sch=C3=B6ffel?= <sils@sils.li>
Date: Wed, 8 May 2024 20:51:09 +0200
Subject: [PATCH] build(flake): add pre-commit-hooks

This enforces formatting rules.
---
 .gitignore |  3 +++
 flake.lock | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 flake.nix  | 25 +++++++++++++++++++++++++
 3 files changed, 82 insertions(+)

diff --git a/.gitignore b/.gitignore
index d168be3..e00d9d7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,9 @@ plugin.txt
 .idea
 .direnv
 
+# Pre Commit hooks
+.pre-commit-config.yaml
+
 # LS
 ## lua
 .luarc.json
diff --git a/flake.lock b/flake.lock
index ca7d44c..b9a4316 100644
--- a/flake.lock
+++ b/flake.lock
@@ -56,6 +56,58 @@
         "type": "github"
       }
     },
+    "git-hooks": {
+      "inputs": {
+        "flake-compat": [
+          "flake-compat"
+        ],
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "gitignore": [
+          "gitignore"
+        ],
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "nixpkgs-stable": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1714478972,
+        "narHash": "sha256-q//cgb52vv81uOuwz1LaXElp3XAe1TqrABXODAEF6Sk=",
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "2849da033884f54822af194400f8dff435ada242",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "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": 1714656196,
@@ -77,6 +129,8 @@
         "crane": "crane",
         "flake-compat": "flake-compat",
         "flake-utils": "flake-utils",
+        "git-hooks": "git-hooks",
+        "gitignore": "gitignore",
         "nixpkgs": "nixpkgs",
         "rust-overlay": "rust-overlay",
         "systems": "systems",
diff --git a/flake.nix b/flake.nix
index 38fd3d7..684d49e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -34,6 +34,16 @@
         nixpkgs.follows = "nixpkgs";
       };
     };
+    git-hooks = {
+      url = "github:cachix/git-hooks.nix";
+      inputs = {
+        flake-compat.follows = "flake-compat";
+        flake-utils.follows = "flake-utils";
+        gitignore.follows = "gitignore";
+        nixpkgs.follows = "nixpkgs";
+        nixpkgs-stable.follows = "nixpkgs";
+      };
+    };
     rust-overlay = {
       url = "github:oxalica/rust-overlay";
       inputs = {
@@ -43,6 +53,12 @@
     };
 
     # inputs for following
+    gitignore = {
+      url = "github:hercules-ci/gitignore.nix";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
     systems = {
       url = "github:nix-systems/x86_64-linux"; # only evaluate for this system
     };
@@ -62,6 +78,7 @@
     self,
     nixpkgs,
     flake-utils,
+    git-hooks,
     treefmt-nix,
     crane,
     rust-overlay,
@@ -141,11 +158,19 @@
       checks = {
         inherit craneBuild;
         formatting = treefmtEval.config.build.check self;
+        pre-commit = git-hooks.lib.${system}.run {
+          src = ./.;
+          hooks.treefmt = {
+            enable = true;
+            package = treefmtEval.config.build.wrapper;
+          };
+        };
       };
 
       formatter = treefmtEval.config.build.wrapper;
 
       devShells.default = pkgs.mkShell {
+        inherit (self.checks.${system}.pre-commit) shellHook;
         packages = with pkgs; [
           cocogitto