chore: initial commit

lib/modules/lefthook.nix

@@ -0,0 +1,152 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}: let
+  inherit (lib) concatStringsSep concatMapStringsSep subtractLists mkEnableOption mkOption types mkIf;
+  cfg = config.lefthook;
+
+  allHookNames = [
+    "applypatch-msg"
+    "pre-applypatch"
+    "post-applypatch"
+    "pre-commit"
+    "prepare-commit-msg"
+    "commit-msg"
+    "post-commit"
+    "pre-rebase"
+    "post-rewrite"
+    "post-checkout"
+    "post-merge"
+    "pre-push"
+    "pre-auto-gc"
+    "post-update"
+    "sendemail-validate"
+    "fsmonitor-watchman"
+    "p4-changelist"
+    "p4-prepare-changelist"
+    "p4-post-changelist"
+    "p4-pre-submit"
+    "post-index-change"
+    "pre-receive"
+    "update"
+    "proc-receive"
+    "reference-transaction"
+    "push-to-checkout"
+    "pre-merge-commit"
+  ];
+  currentHookNames = builtins.filter (h: builtins.elem h allHookNames) (builtins.attrNames cfg.config);
+  unusedNixHookNames = subtractLists allHookNames currentHookNames;
+  unusedNixHookNamesStr = concatStringsSep " " unusedNixHookNames;
+
+  hookContent = hookName:
+    pkgs.writeShellScript hookName ''
+      if [ "$LEFTHOOK" = "0" ]; then
+        exit 0
+      fi
+
+      ${lefthookAlias}/bin/${cfg.alias} run "${hookName}" "$@"
+    '';
+
+  lefthookConfig = (pkgs.formats.yaml {}).generate "lefthook.yaml" cfg.config;
+  lefthookAlias = pkgs.writeShellScriptBin cfg.alias ''
+    if [ "$1" = "install" ]; then
+      echo "Warning, using 'lefthook install' should not be used, use the shellHook instead"
+    fi
+    if [ "$1" = "install" ]; then
+      echo "Warning, using 'lefthook install' should not be used, use the shellHook instead"
+    fi
+    if [ "$1" = "install" ]; then
+      echo "Warning, using 'lefthook install' should not be used, use the shellHook instead"
+    fi
+    LEFTHOOK_CONFIG="${lefthookConfig}" ${pkgs.lefthook}/bin/lefthook ''${@:1}
+  '';
+in {
+  options.lefthook = {
+    enable =
+      mkEnableOption "Lefthook"
+      // {
+        default = cfg.config != {};
+      };
+    shellHook = mkOption {
+      type = types.bool;
+      default = true;
+      description = ''
+        Whether to add a shell hook which automatically installs the git hooks.
+      '';
+    };
+    alias = mkOption {
+      type = types.str;
+      default = "lefthook";
+      example = "hooks";
+      description = ''
+        Alias for the lefthook command.
+      '';
+    };
+    config = mkOption {
+      type = types.attrs;
+      default = {};
+      description = ''
+        Config for lefthook. See https://lefthook.dev/configuration/.
+      '';
+      example = {
+        pre-commit = {
+          parallel = true;
+          jobs = [
+            {
+              name = "hello";
+              run = "echo world";
+            }
+          ];
+        };
+      };
+    };
+
+    outputs = {
+      shellHook = mkOption {
+        type = types.str;
+        readOnly = true;
+        description = ''
+          The script to run on shell activation.
+          It automatically installs the git hooks and removes unused/previously used ones.
+        '';
+      };
+    };
+  };
+  config = {
+    lefthook.outputs.shellHook =
+      # sh
+      ''
+        ${builtins.readFile ./lefthook_helpers.sh}
+
+        # ensure git is available and we are in a Git repository
+        if ! command -v git &> /dev/null; then
+          __log ERROR "Git command not found. Cannot manage Git hooks." >&2
+          return 1
+        fi
+
+        local GIT_REAL_DIR
+        GIT_REAL_DIR=$(git rev-parse --git-dir 2>/dev/null)
+        if [ $? -ne 0 ]; then
+          __log INFO "Not inside a Git repository. Skipping Git hook setup." >&2
+          return 0
+        fi
+        # Use realpath to handle .git file for worktrees, and resolve relative path
+        GIT_REAL_DIR=$(realpath "$GIT_REAL_DIR")
+
+        # clean up unused hooks
+        cleanup_git_hooks "${unusedNixHookNamesStr}"
+
+        ${concatMapStringsSep "\n" (hook: ''
+            setup_git_hook "${hook}" "${hookContent hook}"
+          '')
+          currentHookNames}
+      '';
+    packages = mkIf cfg.enable [lefthookAlias];
+    enterShellCommands."lefthook" = mkIf (cfg.enable && cfg.shellHook) {
+      text = cfg.outputs.shellHook;
+      deps = ["env"];
+    };
+  };
+}