neovim: correctly concat single line configs

The changes introduced in https://github.com/NixOS/nixpkgs/pull/184364#discussion_r945772144
didn't concat correctly the plugin configs when they were a single
string see: https://github.com/nix-community/home-manager/pull/3147

This adds a test for it.

pkgs/applications/editors/neovim/tests/default.nix

@@ -2,6 +2,7 @@
 , lib, fetchFromGitHub, neovimUtils, wrapNeovimUnstable
 , neovim-unwrapped
 , fetchFromGitLab
+, runCommandLocal
 , pkgs
 }:
 let
@@ -19,6 +20,24 @@ let
     }
   ];
 
+  packagesWithSingleLineConfigs = with vimPlugins; [
+    {
+      plugin = vim-obsession;
+      config = ''map <Leader>$ <Cmd>Obsession<CR>'';
+    }
+    {
+      plugin = trouble-nvim;
+      config = ''" placeholder config'';
+    }
+  ];
+
+  nvimConfSingleLines = makeNeovimConfig {
+    plugins = packagesWithSingleLineConfigs;
+    customRC = ''
+      " just a comment
+    '';
+  };
+
   nvimConfNix = makeNeovimConfig {
     inherit plugins;
     customRC = ''
@@ -47,8 +66,9 @@ let
     sha256 = "1ykcvyx82nhdq167kbnpgwkgjib8ii7c92y3427v986n2s5lsskc";
   };
 
+  # neovim-drv must be a wrapped neovim
   runTest = neovim-drv: buildCommand:
-    pkgs.runCommandLocal "test-${neovim-drv.name}" ({
+    runCommandLocal "test-${neovim-drv.name}" ({
       nativeBuildInputs = [ ];
       meta.platforms = neovim-drv.meta.platforms;
     }) (''
@@ -68,6 +88,12 @@ rec {
   ##################
   nvim_with_plugins = wrapNeovim2 "-with-plugins" nvimConfNix;
 
+  singlelinesconfig = runTest (wrapNeovim2 "-single-lines" nvimConfSingleLines) ''
+      assertFileContent \
+        "$vimrcGeneric" \
+        "${./init-single-lines.vim}"
+  '';
+
   nvim_via_override = neovim.override {
     extraName = "-via-override";
     configure = {
@@ -131,7 +157,7 @@ rec {
   nvim_via_override-test = runTest nvim_via_override ''
       assertFileContent \
         "$vimrcGeneric" \
-        "${./neovim-override.vim}"
+        "${./init-override.vim}"
   '';
 
 

pkgs/applications/editors/neovim/tests/init-single-lines.vim

@@ -0,0 +1,3 @@
+map <Leader>$ <Cmd>Obsession<CR>
+" placeholder config
+" just a comment

pkgs/applications/editors/neovim/utils.nix

@@ -49,12 +49,17 @@ let
       };
 
       # transform all plugins into an attrset
-      # { optional = bool; plugin = package; dest = filename; }
-      pluginsNormalized = map (x: if x ? plugin then { dest = "init.vim"; optional = false; } // x else { plugin = x; optional = false;}) plugins;
+      # { optional = bool; plugin = package; }
+      pluginsNormalized = let
+        defaultPlugin = {
+          plugin = null;
+          config = null;
+          optional = false;
+        };
+      in
+        map (x: defaultPlugin // (if (x ? plugin) then x else { plugin = x; })) plugins;
 
-
-
-      pluginRC = lib.concatMapStrings (p: p.config or "") pluginsNormalized;
+      pluginRC = lib.foldl (acc: p: if p.config != null then acc ++ [p.config] else acc) []  pluginsNormalized;
 
       pluginsPartitioned = lib.partition (x: x.optional == true) pluginsNormalized;
       requiredPlugins = vimUtils.requiredPluginsForPackage myVimPackage;
@@ -116,7 +121,11 @@ let
 
       manifestRc = vimUtils.vimrcContent ({ customRC = ""; }) ;
       # we call vimrcContent without 'packages' to avoid the init.vim generation
-      neovimRcContent = vimUtils.vimrcContent ({ beforePlugins = ""; customRC = pluginRC + customRC; packages = null; });
+      neovimRcContent = vimUtils.vimrcContent ({
+        beforePlugins = "";
+        customRC = lib.concatStringsSep "\n" (pluginRC ++ [customRC]);
+        packages = null;
+      });
     in
 
     builtins.removeAttrs args ["plugins"] // {

pkgs/applications/editors/neovim/wrapper.nix

@@ -123,7 +123,7 @@ let
       unwrapped = neovim;
       initRc = neovimRcContent;
 
-      tests = callPackage ./tests.nix {
+      tests = callPackage ./tests {
       };
     };