Move checks to its own file

checks.nix

@@ -0,0 +1,23 @@
+{ system }:
+{ self, nixpkgs, emacs-overlay, ... }@inputs:
+
+let
+  pkgs = import nixpkgs {
+    inherit system;
+    # we are not using emacs-overlay's flake.nix here,
+    # to avoid unnecessary inputs to be added to flake.lock;
+    # this means we need to import the overlay in a hack-ish way
+    overlays = [ (import emacs-overlay) ];
+  };
+in
+{
+  init-example-el = self.outputs.package.${system} {
+    doomPrivateDir = ./test/doom.d;
+    dependencyOverrides = inputs;
+  };
+  init-example-el-emacsGit = self.outputs.package.${system} {
+    doomPrivateDir = ./test/doom.d;
+    dependencyOverrides = inputs;
+    emacsPackages = with pkgs; emacsPackagesFor emacsGit;
+  };
+}

flake.nix

@@ -99,28 +99,7 @@
         package = { dependencyOverrides ? { }, ... }@args:
           pkgs.callPackage self
           (args // { dependencyOverrides = (inputs // dependencyOverrides); });
-      }) // eachSystem [ "x86_64-linux" "aarch64-darwin" ] (system: {
+        checks = import ./checks.nix { inherit system; } inputs;
-        checks =
-          let
-            pkgs = import nixpkgs {
-              inherit system;
-              # we are not using emacs-overlay's flake.nix here,
-              # to avoid unnecessary inputs to be added to flake.lock;
-              # this means we need to import the overlay in a hack-ish way
-              overlays = [ (import emacs-overlay) ];
-            };
-          in
-            {
-              init-example-el = self.outputs.package.${system} {
-                doomPrivateDir = ./test/doom.d;
-                dependencyOverrides = inputs;
-              };
-              init-example-el-emacsGit = self.outputs.package.${system} {
-                doomPrivateDir = ./test/doom.d;
-                dependencyOverrides = inputs;
-                emacsPackages = with pkgs; emacsPackagesFor emacsGit;
-              };
-            };
       }) // {
         hmModule = import ./modules/home-manager.nix inputs;
       };