feat: adds function for generating lefthook configuration files

.gitignore

@@ -1,5 +1,5 @@
 .direnv/
 .justfile
-.pre-commit-config.yaml
 .prettierignore
 site/
+lefthook.yml

flake.nix

@@ -44,9 +44,9 @@
         tools = mkTools [
           pkgs.cue
           pkgs.just
+          pkgs.lefthook
           pkgs.mkdocs
           pkgs.nixpkgs-fmt
-          pkgs.pre-commit
           pkgs.nodePackages.prettier
         ];
 
@@ -64,7 +64,7 @@
             tasks = {
               check = [
                 "@${tools.nixpkgs-fmt.exe} --check flake.nix $(git ls-files '**/*.nix')"
-                "@${tools.prettier.exe} -c ."
+                "@${tools.prettier.exe} --check ."
                 "@nix flake check"
                 "@mkdocs build --strict && rm -rf site"
               ];
@@ -77,18 +77,26 @@
               ];
             };
           };
-          # Pre-commit configuration
-          "pre-commit.mkLocalConfig" = {
-            nixpkgs-fmt = {
-              entry = tools.nixpkgs-fmt.exe;
-              language = "system";
-              files = "\\.nix";
+          # Lefthook configuration
+          "lefthook.mkConfig" = {
+            pre-commit = {
+              commands = {
+                nixpkgs-fmt = {
+                  run = "${tools.nixpkgs-fmt.exe} --check {staged_files}";
+                  glob = "*.nix";
+                };
+                prettier = {
+                  run = "${tools.prettier.exe} --check {staged_files}";
+                  glob = "*.{yaml,yml,md}";
+                };
+              };
             };
           };
           # Prettier
           "prettier.mkIgnoreConfig" = [
             ".direnv"
             "tests"
+            "lefthook.yml"
           ];
         };
       in
@@ -102,18 +110,15 @@
         # Local tests
         checks = {
           just = pkgs.callPackage ./tests/just { inherit pkgs plugins; };
+          lefthook = pkgs.callPackage ./tests/lefthook { inherit pkgs plugins; };
           pre-commit = pkgs.callPackage ./tests/pre-commit { inherit pkgs plugins; };
           prettier = pkgs.callPackage ./tests/prettier { inherit pkgs plugins; };
         };
 
-        # Local shell for development.
-        # The shell does not currently build on i686-linux machines due to a
-        # downstream dependency of pkgs.pre-commit.
-        # See: https://github.com/NixOS/nixpkgs/issues/174847
-        # The shell also does not currently work on x86_64-darwin due to a
+        # The shell does not currently work on x86_64-darwin due to a
         # downstream dependency of mkdocs.
         # See: https://github.com/NixOS/nixpkgs/pull/171388
-        devShells = nixpkgs.lib.optionalAttrs (!builtins.elem system [ "i686-linux" "x86_64-darwin" ]) {
+        devShells = nixpkgs.lib.optionalAttrs (!builtins.elem system [ "x86_64-darwin" ]) {
           default = pkgs.mkShell {
             shellHook = (lib.mkAll configurations).shellHook;
             packages = tools.all ++ deps;

plugins/default.nix

@@ -4,6 +4,10 @@
   */
   just = import ./just { inherit pkgs lib; };
 
+  /* https://github.com/evilmartians/lefthook
+  */
+  lefthook = import ./lefthook { inherit pkgs lib; };
+
   /* https://github.com/pre-commit/pre-commit
   */
   pre-commit = import ./pre-commit { inherit pkgs lib; };

plugins/lefthook/default.nix

@@ -0,0 +1,6 @@
+{ pkgs, lib }:
+{
+  /* Creates a lefthook.yml file for configuring lefthook.
+  */
+  mkConfig = import ./mkConfig.nix { inherit pkgs lib; };
+}

plugins/lefthook/mkConfig.nix

@@ -0,0 +1,33 @@
+{ pkgs, lib }:
+data:
+with pkgs.lib;
+let
+  files = [ ./template.cue ];
+  output = "lefthook.yml";
+  lefthook = pkgs.lefthook;
+
+  # Add an extra hook for adding required stages whenever the file changes
+  skip_attrs = [
+    "colors"
+    "extends"
+    "skip_output"
+    "source_dir"
+    "source_dir_local"
+  ];
+  stages = builtins.attrNames (builtins.removeAttrs data skip_attrs);
+  stagesStr = builtins.concatStringsSep " " stages;
+  shellHookExtra = ''
+    # Install configured hooks
+    for stage in ${stagesStr}; do
+      ${lefthook}/bin/lefthook add -a "$stage"
+    done
+  '';
+
+  # Generate the module
+  result = lib.mkTemplate {
+    inherit data files output shellHookExtra;
+  };
+in
+{
+  inherit (result) configFile shellHook;
+}

plugins/lefthook/template.cue

@@ -0,0 +1,38 @@
+#Config: {
+    [string]: #Hook
+    colors?: bool | *true
+    extends?: [...string]
+    skip_output?: [...string]
+    source_dir?: string
+    source_dir_local?: string
+    ...
+}
+
+#Hook: {
+    commands?: [string]: #Command
+    exclude_tags?: [...string]
+    parallel?: bool | *false
+    piped?: bool | *false
+    scripts?: [string]: #Script
+    ...
+}
+
+#Command: {
+    exclude?: string
+    files?: string
+    glob?: string
+    root?: string
+    run: string
+    skip?: bool | [...string]
+    tags?: string
+    ...
+}
+
+#Script: {
+    runner: string
+    ...
+}
+
+{
+    #Config
+}

tests/lefthook/default.nix

@@ -0,0 +1,36 @@
+{ pkgs, plugins }:
+let
+  output = plugins.lefthook.mkConfig {
+    commit-msg = {
+      scripts = {
+        template_checker = { runner = "bash"; };
+      };
+    };
+    pre-commit = {
+      commands = {
+        stylelint = {
+          tags = "frontend style";
+          glob = "*.js";
+          run = "yarn stylelint {staged_files}";
+        };
+        rubocop = {
+          tags = "backend style";
+          glob = "*.rb";
+          exclude = "application.rb|routes.rb";
+          run = "bundle exec rubocop --force-exclusion {all_files}";
+        };
+      };
+      scripts = {
+        "good_job.js" = { runner = "node"; };
+      };
+    };
+  };
+
+  result = pkgs.runCommand "test.lefthook"
+    { }
+    ''
+      cmp "${./expected.yml}" "${output.configFile}"
+      touch $out
+    '';
+in
+result

tests/lefthook/expected.yml

@@ -0,0 +1,18 @@
+commit-msg:
+  scripts:
+    template_checker:
+      runner: bash
+pre-commit:
+  commands:
+    rubocop:
+      exclude: application.rb|routes.rb
+      glob: '*.rb'
+      run: bundle exec rubocop --force-exclusion {all_files}
+      tags: backend style
+    stylelint:
+      glob: '*.js'
+      run: yarn stylelint {staged_files}
+      tags: frontend style
+  scripts:
+    good_job.js:
+      runner: node