refactor(nix): move style app wiring into dotfiles

docs/TODO.md

@@ -99,6 +99,7 @@
 # tech debt
 
 - better remote deployment
+- expose remote deployment as a flake app, replacing the Fish-only `deploy-to` workflow
 - centralize shared system group names, starting with the `storage` group
 
 ## nix refactor

flake.nix

@@ -75,42 +75,10 @@
   };
 
   outputs =
-    {
+    { self, nixpkgs, ... }@inputs:
-      self,
+    import ./src/dotfiles {
-      nixpkgs,
+      inherit inputs self;
-      treefmt-nix,
+      lib = nixpkgs.lib;
-      ...
+      root = ./configs/nixos;
-    }@inputs:
-    let
-      system = "x86_64-linux";
-      pkgs = nixpkgs.legacyPackages.${system};
-      treefmtEval = treefmt-nix.lib.evalModule pkgs ./treefmt.nix;
-      nixStyleCheck = pkgs.writeShellApplication {
-        name = "nix-style-check";
-        runtimeInputs = [
-          treefmtEval.config.build.wrapper
-          pkgs.statix
-          pkgs.deadnix
-        ];
-        text = ''
-          treefmt --fail-on-change
-          statix check .
-          deadnix --fail --no-lambda-pattern-names --no-underscore .
-        '';
-      };
-    in
-    {
-      formatter.${system} = treefmtEval.config.build.wrapper;
-
-      apps.${system}.nix-style-check = {
-        type = "app";
-        program = "${nixStyleCheck}/bin/nix-style-check";
-      };
-
-      nixosConfigurations = (import ./src/dotfiles {
-        inherit inputs self;
-        lib = nixpkgs.lib;
-        root = ./configs/nixos;
-      }).nixosConfigurations;
     };
 }

src/dotfiles/apps.nix

@@ -0,0 +1,40 @@
+{
+  inputs,
+  lib,
+}:
+let
+  system = "x86_64-linux";
+  pkgs = inputs.nixpkgs.legacyPackages.${system};
+
+  treefmtEval = inputs.treefmt-nix.lib.evalModule pkgs {
+    projectRootFile = "flake.nix";
+
+    programs.nixfmt.enable = true;
+
+    settings.formatter.nixfmt.excludes = [
+      "configs/nixos/hosts/*/hardware-configuration.nix"
+    ];
+  };
+
+  styleCheck = pkgs.writeShellApplication {
+    name = "style-check";
+    runtimeInputs = [
+      treefmtEval.config.build.wrapper
+      pkgs.statix
+      pkgs.deadnix
+    ];
+    text = ''
+      treefmt --fail-on-change
+      statix check .
+      deadnix --fail --no-lambda-pattern-names --no-underscore .
+    '';
+  };
+in
+{
+  formatter.${system} = treefmtEval.config.build.wrapper;
+
+  apps.${system}.style-check = {
+    type = "app";
+    program = lib.getExe styleCheck;
+  };
+}

src/dotfiles/default.nix

@@ -38,6 +38,13 @@ let
       ;
     registry = registry.collected;
   };
+
+  flakeApps = import ./apps.nix {
+    inherit
+      inputs
+      lib
+      ;
+  };
 in
 {
   nixosConfigurations = import ./hosts.nix {
@@ -52,3 +59,4 @@ in
     root = root + "/hosts";
   };
 }
+// flakeApps

treefmt.nix

@@ -1,9 +0,0 @@
-{
-  projectRootFile = "flake.nix";
-
-  programs.nixfmt.enable = true;
-
-  settings.formatter.nixfmt.excludes = [
-    "configs/nixos/hosts/*/hardware-configuration.nix"
-  ];
-}