lib/tests: Add tests for emptyValue

lib/tests/modules.sh

···
 checkConfigOutput '^"a y z"$' config.resultFooBar ./declare-variants.nix ./define-variant.nix
 checkConfigOutput '^"a b c"$' config.resultFooFoo ./declare-variants.nix ./define-variant.nix
 
+## emptyValue's
+checkConfigOutput "[ ]" config.list.a ./emptyValues.nix
+checkConfigOutput "{ }" config.attrs.a ./emptyValues.nix
+checkConfigOutput "null" config.null.a ./emptyValues.nix
+checkConfigOutput "{ }" config.submodule.a ./emptyValues.nix
+# These types don't have empty values
+checkConfigError 'The option .int.a. is used but not defined' config.int.a ./emptyValues.nix
+checkConfigError 'The option .nonEmptyList.a. is used but not defined' config.nonEmptyList.a ./emptyValues.nix
+
 cat <<EOF
 ====== module tests ======
 $pass Pass

lib/tests/modules/emptyValues.nix

···
+{ lib, ... }:
+let
+  inherit (lib) types;
+in {
+
+  options = {
+    int = lib.mkOption {
+      type = types.lazyAttrsOf types.int;
+    };
+    list = lib.mkOption {
+      type = types.lazyAttrsOf (types.listOf types.int);
+    };
+    nonEmptyList = lib.mkOption {
+      type = types.lazyAttrsOf (types.nonEmptyListOf types.int);
+    };
+    attrs = lib.mkOption {
+      type = types.lazyAttrsOf (types.attrsOf types.int);
+    };
+    null = lib.mkOption {
+      type = types.lazyAttrsOf (types.nullOr types.int);
+    };
+    submodule = lib.mkOption {
+      type = types.lazyAttrsOf (types.submodule {});
+    };
+  };
+
+  config = {
+    int.a = lib.mkIf false null;
+    list.a = lib.mkIf false null;
+    nonEmptyList.a = lib.mkIf false null;
+    attrs.a = lib.mkIf false null;
+    null.a = lib.mkIf false null;
+    submodule.a = lib.mkIf false null;
+  };
+
+}