From f6214eb786bffd05a17941bfe68cdecb0c0438af Mon Sep 17 00:00:00 2001
From: Johannes Kirschbauer <hsjobeki@gmail.com>
Date: Sun, 19 Jan 2025 16:22:24 +0100
Subject: [PATCH] lib/types: types.functionTo deprecate functor.wrapped in
 favor of functor.payload.elemType

---
 doc/release-notes/rl-2505.section.md     |  1 +
 lib/tests/modules.sh                     |  6 ++++++
 lib/tests/modules/deprecated-wrapped.nix | 11 +++++++++++
 lib/types.nix                            |  4 +++-
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/doc/release-notes/rl-2505.section.md b/doc/release-notes/rl-2505.section.md
index c71ac169d78b..240cda17b1eb 100644
--- a/doc/release-notes/rl-2505.section.md
+++ b/doc/release-notes/rl-2505.section.md
@@ -77,6 +77,7 @@
     - `lib.types.listOf`
     - `lib.types.unique` and `lib.types.uniq`
     - `lib.types.nullOr`
+    - `lib.types.functionTo`
 
 - Plasma 5 and Qt 5 based versions of associated software are deprecated in NixOS 25.05, and will be removed in NixOS 25.11. Users are encouraged to upgrade to Plasma 6.
 
diff --git a/lib/tests/modules.sh b/lib/tests/modules.sh
index 5bdc6e983501..ffdc1505f06d 100755
--- a/lib/tests/modules.sh
+++ b/lib/tests/modules.sh
@@ -427,6 +427,12 @@ NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribu
 
 NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribute .*is accessed, use `.*nestedTypes.elemType` instead.' options.nullOr.type.nestedTypes.elemType.functor.wrapped ./deprecated-wrapped.nix
 NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribute .*is accessed, use `.*nestedTypes.elemType` instead.' options.mergedNullOr.type.nestedTypes.elemType.functor.wrapped ./deprecated-wrapped.nix
+# functionTo
+NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribute .*is accessed, use `.*nestedTypes.elemType` instead.' options.functionTo.type.functor.wrapped ./deprecated-wrapped.nix
+NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribute .*is accessed, use `.*nestedTypes.elemType` instead.' options.mergedFunctionTo.type.functor.wrapped ./deprecated-wrapped.nix
+
+NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribute .*is accessed, use `.*nestedTypes.elemType` instead.' options.functionTo.type.nestedTypes.elemType.functor.wrapped ./deprecated-wrapped.nix
+NIX_ABORT_ON_WARN=1 checkConfigError 'The deprecated `.*functor.wrapped` attribute .*is accessed, use `.*nestedTypes.elemType` instead.' options.mergedFunctionTo.type.nestedTypes.elemType.functor.wrapped ./deprecated-wrapped.nix
 
 # Even with multiple assignments, a type error should be thrown if any of them aren't valid
 checkConfigError 'A definition for option .* is not of type .*' \
diff --git a/lib/tests/modules/deprecated-wrapped.nix b/lib/tests/modules/deprecated-wrapped.nix
index fcdfef7dea71..7db64edfcce3 100644
--- a/lib/tests/modules/deprecated-wrapped.nix
+++ b/lib/tests/modules/deprecated-wrapped.nix
@@ -8,6 +8,7 @@ let
     listOf
     unique
     nullOr
+    functionTo
     ;
 in
 {
@@ -42,6 +43,13 @@ in
         options.mergedNullOr = mkOption {
           type = nullOr (listOf types.str);
         };
+        # nullOr
+        options.functionTo = mkOption {
+          type = functionTo (listOf types.str);
+        };
+        options.mergedFunctionTo = mkOption {
+          type = functionTo (listOf types.str);
+        };
       }
     )
     # Module B
@@ -60,6 +68,9 @@ in
         options.mergedNullOr = mkOption {
           type = nullOr (listOf types.str);
         };
+        options.mergedFunctionTo = mkOption {
+          type = functionTo (listOf types.str);
+        };
       }
     )
   ];
diff --git a/lib/types.nix b/lib/types.nix
index f38f96c33786..24d5192225a3 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -887,7 +887,9 @@ rec {
       getSubOptions = prefix: elemType.getSubOptions (prefix ++ [ "<function body>" ]);
       getSubModules = elemType.getSubModules;
       substSubModules = m: functionTo (elemType.substSubModules m);
-      functor = (defaultFunctor "functionTo") // { wrapped = elemType; };
+      functor = (elemTypeFunctor "functionTo" { inherit elemType; }) // {
+        type = payload: types.functionTo payload.elemType;
+      };
       nestedTypes.elemType = elemType;
     };