Expose specialArgs.modulesPath and specialArgs.extraModulesPath to flake module consumers

.github/workflows/nix.yml

@@ -41,7 +41,15 @@ jobs:
           name: numtide
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
       - run: nix flake check
-      - run: nix develop -c echo OK
+      - name: Run devshell entry sanity checks
+        run: |
+          nix develop -c echo OK
+          for tmpl in ./templates/*; do
+            if ! [ -d "$tmpl" ]; then
+              continue
+            fi
+            nix develop --override-input devshell . "$tmpl" -c echo OK
+          done
       - name: Run nix flake archive
         run: nix flake archive
   docs:

default.nix

@@ -26,13 +26,13 @@ let
 in
 rec {
   # Folder that contains all the extra modules
-  extraModulesDir = toString ./extra;
+  extraModulesPath = toString ./extra;
 
   # Get the modules documentation from an empty evaluation
   modules-docs = (eval {
     configuration = {
       # Load all of the extra modules so they appear in the docs
-      imports = importTree extraModulesDir;
+      imports = importTree extraModulesPath;
     };
   }).config.modules-docs;
 

docs/src/extending.md

@@ -31,7 +31,9 @@ lang = "en_US.UTF-8"
 From a nix flake you would import it like
 
 ```nix
-imports = ["${devshell}/extra/locale.nix"];
+devshell.mkShell ({ extraModulesPath, ... }: {
+  imports = ["${extraModulesPath}/extra/locale.nix"];
+})
 ```
 
 ## Building your own modules

flake-module.nix

@@ -18,9 +18,7 @@ in
           Used to define devshells. not to be confused with `devShells`
         '';
 
-        type = types.lazyAttrsOf (types.submoduleWith {
-          modules = import ./modules/modules.nix { inherit pkgs lib; };
-        });
+        type = types.lazyAttrsOf (types.submoduleWith (import ./modules/eval-args.nix { inherit pkgs lib; }));
         default = { };
       };
       config.devShells = lib.mapAttrs (_name: devshell: devshell.devshell.shell) config.devshells;

modules/default.nix

@@ -5,18 +5,11 @@ nixpkgs:
 , extraSpecialArgs ? { }
 }:
 let
-  devenvModules = import ./modules.nix {
+  module = lib.evalModules (import ./eval-args.nix {
+    inherit lib extraSpecialArgs;
     pkgs = nixpkgs;
-    inherit lib;
-  };
-
-  module = lib.evalModules {
-    modules = [ configuration ] ++ devenvModules;
-    specialArgs = {
-      modulesPath = builtins.toString ./.;
-      extraModulesPath = builtins.toString ../extra;
-    } // extraSpecialArgs;
-  };
+    modules = [ configuration ];
+  });
 in
 {
   inherit (module) config options;

modules/eval-args.nix

@@ -0,0 +1,18 @@
+# Arguments for `lib.evalModules` or `types.submoduleWith`.
+{ pkgs
+, lib
+, modules ? [ ]
+, extraSpecialArgs ? { }
+}:
+let
+  devenvModules = import ./modules.nix {
+    inherit lib pkgs;
+  };
+in
+{
+  modules = (lib.toList modules) ++ devenvModules;
+  specialArgs = {
+    modulesPath = builtins.toString ./.;
+    extraModulesPath = builtins.toString ../extra;
+  } // extraSpecialArgs;
+}

nix/importTOML.nix

@@ -6,14 +6,14 @@ let
       dir = toString (builtins.dirOf file);
       data = builtins.fromTOML (builtins.readFile file);
 
-      extraModulesDir = toString ../extra;
-      extraModules = builtins.readDir extraModulesDir;
+      extraModulesPath = toString ../extra;
+      extraModules = builtins.readDir extraModulesPath;
 
       importModule = str:
         let
           repoFile = "${dir}/${str}";
           extraFile =
-            "${extraModulesDir}/${builtins.replaceStrings [ "." ] [ "/" ] str}.nix";
+            "${extraModulesPath}/${builtins.replaceStrings [ "." ] [ "/" ] str}.nix";
         in
         # First try to import from the user's repository
         if lib.hasPrefix "./" str || lib.hasSuffix ".nix" str || lib.hasSuffix ".toml" str

templates/flake-parts/flake.nix

@@ -19,7 +19,24 @@
       ];
 
       perSystem = { pkgs, ... }: {
-        devshells.default = { };
+        devshells.default = ({ extraModulesPath, ... } @ args: {
+          # `extraModulesPath` provides access to additional modules that are
+          # not included in the standard devshell modules list.
+          #
+          # Please see https://numtide.github.io/devshell/extending.html for
+          # documentation on consuming extra modules, and see
+          # https://github.com/numtide/devshell/tree/main/extra for the
+          # extra modules that are currently available.
+          imports = [
+            "${extraModulesPath}/git/hooks.nix"
+          ];
+
+          git.hooks.enable = false;
+          git.hooks.pre-commit.text = ''
+            echo 1>&2 'time to implement a pre-commit hook!'
+            exit 1
+          '';
+        });
       };
     };
 }