treewide: avoid passing pkgs to our lib

In the two places where our "helpers" lib is exclusively internal
(flake module args and building the docs), we no longer supply `pkgs`.

In the other 4 locations, we now note why we still do in a comment.

docs/default.nix

@@ -7,7 +7,7 @@ let
   # We overlay a few tweaks into pkgs, for use in the docs
   pkgs = import ./pkgs.nix { inherit system nixpkgs; };
   inherit (pkgs) lib;
-  helpers = import ../lib { inherit lib pkgs; };
+  helpers = import ../lib { inherit lib; };
 
   nixvimPath = toString ./..;
 
@@ -34,7 +34,9 @@ let
     };
 
   evaledModules = lib.evalModules {
-    inherit (helpers.modules) specialArgs;
+    specialArgs = helpers.modules.specialArgsWith {
+      defaultPkgs = pkgs;
+    };
     modules = [
       ../modules/top-level
       { isDocs = true; }

flake-modules/legacy-packages.nix

@@ -1,8 +1,8 @@
+{ helpers, ... }:
 {
   perSystem =
     {
       pkgs,
-      helpers,
       makeNixvimWithModule,
       ...
     }:

flake-modules/lib.nix

@@ -5,11 +5,7 @@
   ...
 }:
 {
-  perSystem =
+  _module.args.helpers = import ../lib { inherit lib; };
-    { pkgs, ... }:
-    {
-      _module.args.helpers = import ../lib { inherit lib pkgs; };
-    };
 
   # TODO: output lib without pkgs at the top-level
   flake.lib = lib.genAttrs config.systems (
@@ -18,6 +14,7 @@
       {
         # NOTE: this is the publicly documented flake output we've had for a while
         check = import ../lib/tests.nix { inherit lib pkgs; };
+        # NOTE: user-facing so we must include the legacy `pkgs` argument
         helpers = import ../lib { inherit lib pkgs; };
       }
     )

flake-modules/tests.nix

@@ -1,11 +1,10 @@
-{ self, ... }:
+{ self, helpers, ... }:
 {
   perSystem =
     {
       pkgs,
       pkgsUnfree,
       system,
-      helpers,
       makeNixvimWithModule,
       self',
       ...

lib/tests.nix

@@ -45,6 +45,7 @@ let
     }@args:
     let
       helpers = import ../lib {
+        # NOTE: must match the user-facing functions, so we still include the `pkgs` argument
         inherit pkgs lib;
         # TODO: deprecate helpers.enableExceptInTests,
         # add a context option e.g. `config.isTest`?

wrappers/_shared.nix

@@ -46,6 +46,7 @@ in
   config = mkMerge [
     {
       # Make our lib available to the host modules
+      # NOTE: user-facing so we must include the legacy `pkgs` argument
       lib.nixvim = lib.mkDefault (import ../lib { inherit pkgs lib; });
 
       # Make nixvim's "extended" lib available to the host's module args

wrappers/standalone.nix

@@ -7,6 +7,7 @@ default_pkgs: self:
   module,
 }:
 let
+  # NOTE: user-facing so we must include the legacy `pkgs` argument
   helpers = import ../lib { inherit pkgs lib _nixvimTests; };
 
   inherit (helpers.modules) evalNixvim;