allow facter report to be empty.

This makes our code also more robust, if things in the report are not
present.

Author: Mic92

flake.nix

@@ -62,6 +62,20 @@
         checks = eachSystem (
           { pkgs, ... }:
           {
+            minimal-machine =
+              (pkgs.nixos [
+                publicInputs.self.nixosModules.facter
+                (
+                  { lib, config, ... }:
+                  {
+                    boot.loader.grub.devices = lib.mkForce [ "/dev/sda" ];
+                    fileSystems."/".device = lib.mkDefault "/dev/sda";
+                    users.users.root.initialPassword = "fnord23";
+                    system.stateVersion = config.system.nixos.version;
+                    nixpkgs.pkgs = pkgs;
+                  }
+                )
+              ]).config.system.build.toplevel;
             lib-tests = pkgs.runCommandLocal "lib-tests" { nativeBuildInputs = [ pkgs.nix-unit ]; } ''
               export HOME="$(realpath .)"
               export NIX_CONFIG='

modules/nixos/facter.nix

@@ -1,13 +1,8 @@
 {
   lib,
   config,
-  options,
   ...
 }:
-let
-  cfg = config.facter;
-  modulePath = lib.concatStringsSep "/" (lib.take 4 (lib.splitString [ "/" ] __curPos.file));
-in
 {
   imports = [
     ./bluetooth.nix
@@ -23,12 +18,13 @@ in
   options.facter = with lib; {
     report = mkOption {
       type = types.raw;
-      default = builtins.fromJSON (builtins.readFile config.facter.reportPath);
+      default = if config.facter.reportPath == null then {} else builtins.fromJSON (builtins.readFile config.facter.reportPath);
       description = "An import for the reportPath.";
     };
 
     reportPath = mkOption {
-      type = types.path;
+      type = types.nullOr types.path;
+      default = null;
       description = "Path to a report generated by nixos-facter.";
     };
 

modules/nixos/virtualisation.nix

@@ -25,28 +25,28 @@ in
       defaultText = "hardware dependent";
     };
     oracle.enable = lib.mkEnableOption "Enable the Facter Virtualisation Oracle module" // {
-      default = report.virtualisation == "oracle";
+      default = report.virtualisation or null == "oracle";
       defaultText = "environment dependent";
     };
     parallels.enable = lib.mkEnableOption "Enable the Facter Virtualisation Parallels module" // {
-      default = report.virtualisation == "parallels";
+      default = report.virtualisation or null == "parallels";
       defaultText = "environment dependent";
     };
     qemu.enable = lib.mkEnableOption "Enable the Facter Virtualisation Qemu module" // {
-      default = builtins.elem report.virtualisation [
+      default = builtins.elem (report.virtualisation or null) [
         "qemu"
         "kvm"
         "bochs"
       ];
       defaultText = "environment dependent";
     };
     hyperv.enable = lib.mkEnableOption "Enable the Facter Virtualisation Hyper-V module" // {
-      default = report.virtualisation == "microsoft";
+      default = report.virtualisation or null == "microsoft";
       defaultText = "environment dependent";
     };
     # no virtualisation detected
     none.enable = lib.mkEnableOption "Enable the Facter Virtualisation None module" // {
-      default = report.virtualisation == "none";
+      default = report.virtualisation or null == "none";
       defaultText = "environment dependent";
     };
   };