modules/dependencies: introduce top-level (internal) __depPackages option

modules/dependencies.nix

@@ -5,68 +5,9 @@
   ...
 }:
 let
-  cfg = config.dependencies;
+  inherit (lib) types;
 
-  packages = {
+  cfg = config.dependencies;
-    bat.default = "bat";
-    codeium.default = "codeium";
-    coreutils = {
-      default = "coreutils";
-      example = "uutils-coreutils";
-    };
-    cornelis.default = "cornelis";
-    ctags.default = "ctags";
-    curl.default = "curl";
-    direnv.default = "direnv";
-    distant.default = "distant";
-    fish.default = "fish";
-    flutter.default = "flutter";
-    fzf = {
-      default = "fzf";
-      example = "skim";
-    };
-    gcc.default = "gcc";
-    gh.default = "gh";
-    git = {
-      default = "git";
-      example = "gitMinimal";
-    };
-    glow.default = "glow";
-    go.default = "go";
-    godot.default = "godot_4";
-    gzip.default = "gzip";
-    lazygit.default = "lazygit";
-    lean.default = "lean4";
-    ledger.default = "ledger";
-    llm-ls.default = "llm-ls";
-    manix.default = "manix";
-    nodejs = {
-      default = "nodejs";
-      example = "nodejs_22";
-    };
-    plantuml.default = "plantuml";
-    ripgrep.default = "ripgrep";
-    rust-analyzer.default = "rust-analyzer";
-    sd.default = "sd";
-    sed.default = "gnused";
-    texpresso.default = "texpresso";
-    tinymist.default = "tinymist";
-    tmux.default = "tmux";
-    tree-sitter.default = "tree-sitter";
-    typst.default = "typst";
-    ueberzug.default = "ueberzugpp";
-    util-linux.default = "util-linux";
-    websocat.default = "websocat";
-    wezterm.default = "wezterm";
-    which.default = "which";
-    xxd.default = [
-      "unixtools"
-      "xxd"
-    ];
-    yazi.default = "yazi";
-    yq.default = "yq";
-    zk.default = "zk";
-  };
 
   mkDependencyOption = name: properties: {
     enable = lib.mkEnableOption "Add ${name} to dependencies.";
@@ -75,7 +16,7 @@ let
       lib.mkPackageOption pkgs name properties
       # Handle example manually so that we can embed the original attr-path within
       # the literalExpression object. This simplifies testing the examples.
-      // lib.optionalAttrs (properties ? example) {
+      // lib.optionalAttrs (properties.example != null) {
         example =
           if properties.example._type or null == "literalExpression" then
             properties.example
@@ -89,7 +30,37 @@ let
   };
 in
 {
-  options.dependencies = lib.mapAttrs mkDependencyOption packages;
+  options = {
+    __depPackages = lib.mkOption {
+      type = types.attrsOf (
+        types.submodule {
+          options = {
+            default = lib.mkOption {
+              type = with types; either str (listOf str);
+              description = ''
+                Default name (or path) for this package.
+              '';
+              example = "git";
+            };
+
+            example = lib.mkOption {
+              type = with types; nullOr str;
+              description = ''
+                Example of another package to use instead of the default.
+              '';
+              example = "gitMinimal";
+              default = null;
+            };
+          };
+        }
+      );
+      default = { };
+      internal = true;
+      visible = false;
+    };
+
+    dependencies = lib.mapAttrs mkDependencyOption config.__depPackages;
+  };
 
   config = {
     extraPackages = lib.pipe cfg [
@@ -97,5 +68,66 @@ in
       (builtins.filter (p: p.enable))
       (builtins.map (p: p.package))
     ];
+
+    __depPackages = {
+      bat.default = "bat";
+      codeium.default = "codeium";
+      coreutils = {
+        default = "coreutils";
+        example = "uutils-coreutils";
+      };
+      cornelis.default = "cornelis";
+      ctags.default = "ctags";
+      curl.default = "curl";
+      direnv.default = "direnv";
+      distant.default = "distant";
+      fish.default = "fish";
+      flutter.default = "flutter";
+      fzf = {
+        default = "fzf";
+        example = "skim";
+      };
+      gcc.default = "gcc";
+      gh.default = "gh";
+      git = {
+        default = "git";
+        example = "gitMinimal";
+      };
+      glow.default = "glow";
+      go.default = "go";
+      godot.default = "godot_4";
+      gzip.default = "gzip";
+      lazygit.default = "lazygit";
+      lean.default = "lean4";
+      ledger.default = "ledger";
+      llm-ls.default = "llm-ls";
+      manix.default = "manix";
+      nodejs = {
+        default = "nodejs";
+        example = "nodejs_22";
+      };
+      plantuml.default = "plantuml";
+      ripgrep.default = "ripgrep";
+      rust-analyzer.default = "rust-analyzer";
+      sd.default = "sd";
+      sed.default = "gnused";
+      texpresso.default = "texpresso";
+      tinymist.default = "tinymist";
+      tmux.default = "tmux";
+      tree-sitter.default = "tree-sitter";
+      typst.default = "typst";
+      ueberzug.default = "ueberzugpp";
+      util-linux.default = "util-linux";
+      websocat.default = "websocat";
+      wezterm.default = "wezterm";
+      which.default = "which";
+      xxd.default = [
+        "unixtools"
+        "xxd"
+      ];
+      yazi.default = "yazi";
+      yq.default = "yq";
+      zk.default = "zk";
+    };
   };
 }