GC root for fetched nixpkgs/lib content

tests/modules/functionTo/list-order.nix

@@ -0,0 +1,25 @@
+
+{ lib, config, ... }:
+let
+  inherit (lib) types;
+in {
+  options = {
+    fun = lib.mkOption {
+      type = types.functionTo (types.listOf types.str);
+    };
+
+    result = lib.mkOption {
+      type = types.str;
+      default = toString (config.fun {
+        a = "a";
+        b = "b";
+        c = "c";
+      });
+    };
+  };
+
+  config.fun = lib.mkMerge [
+    (input: lib.mkAfter [ input.a ])
+    (input: [ input.b ])
+  ];
+}

tests/modules/functionTo/merging-attrs.nix

@@ -0,0 +1,27 @@
+{ lib, config, ... }:
+let
+  inherit (lib) types;
+in {
+  options = {
+    fun = lib.mkOption {
+      type = types.functionTo (types.attrsOf types.str);
+    };
+
+    result = lib.mkOption {
+      type = types.str;
+      default = toString (lib.attrValues (config.fun {
+        a = "a";
+        b = "b";
+        c = "c";
+      }));
+    };
+  };
+
+  config.fun = lib.mkMerge [
+    (input: { inherit (input) a; })
+    (input: { inherit (input) b; })
+    (input: {
+      b = lib.mkForce input.c;
+    })
+  ];
+}

tests/modules/functionTo/merging-list.nix

@@ -0,0 +1,24 @@
+{ lib, config, ... }:
+let
+  inherit (lib) types;
+in {
+  options = {
+    fun = lib.mkOption {
+      type = types.functionTo (types.listOf types.str);
+    };
+
+    result = lib.mkOption {
+      type = types.str;
+      default = toString (config.fun {
+        a = "a";
+        b = "b";
+        c = "c";
+      });
+    };
+  };
+
+  config.fun = lib.mkMerge [
+    (input: [ input.a ])
+    (input: [ input.b ])
+  ];
+}

tests/modules/functionTo/submodule-options.nix

@@ -0,0 +1,61 @@
+{ lib, config, options, ... }:
+let
+  inherit (lib) types;
+in
+{
+  imports = [
+
+    # fun.<function-body>.a
+    ({ ... }: {
+      options = {
+        fun = lib.mkOption {
+          type = types.functionTo (types.submodule {
+            options.a = lib.mkOption { default = "a"; };
+          });
+        };
+      };
+    })
+
+    # fun.<function-body>.b
+    ({ ... }: {
+      options = {
+        fun = lib.mkOption {
+          type = types.functionTo (types.submodule {
+            options.b = lib.mkOption { default = "b"; };
+          });
+        };
+      };
+    })
+  ];
+
+  options = {
+    result = lib.mkOption
+      {
+        type = types.str;
+        default = lib.concatStringsSep " " (lib.attrValues (config.fun (throw "shouldn't use input param")));
+      };
+
+    optionsResult = lib.mkOption
+      {
+        type = types.str;
+        default = lib.concatStringsSep " "
+          (lib.concatLists
+            (lib.mapAttrsToList
+              (k: v:
+                if k == "_module"
+                then [ ]
+                else [ (lib.showOption v.loc) ]
+              )
+              (
+                (options.fun.type.getSubOptions [ "fun" ])
+              )
+            )
+          );
+      };
+  };
+
+  config.fun = lib.mkMerge
+    [
+      (input: { b = "bee"; })
+    ];
+}

tests/modules/functionTo/trivial.nix

@@ -0,0 +1,17 @@
+{ lib, config, ... }:
+let
+  inherit (lib) types;
+in {
+  options = {
+    fun = lib.mkOption {
+      type = types.functionTo types.str;
+    };
+
+    result = lib.mkOption {
+      type = types.str;
+      default = config.fun "input";
+    };
+  };
+
+  config.fun = input: "input is ${input}";
+}

tests/modules/functionTo/wrong-type.nix

@@ -0,0 +1,18 @@
+
+{ lib, config, ... }:
+let
+  inherit (lib) types;
+in {
+  options = {
+    fun = lib.mkOption {
+      type = types.functionTo types.str;
+    };
+
+    result = lib.mkOption {
+      type = types.str;
+      default = config.fun 0;
+    };
+  };
+
+  config.fun = input: input + 1;
+}