neovim: add 'autowrapRuntimeDeps' to append (#358587)

plugin runtime dependencies. A recurrent question is how to make LSP
work on nix, with users wanting to install masons etc. I think it makes
sense for neovim to install neovim plugins in a way that they work out
of the box. That's one of the strengths of nix and a shortcoming of the
neovim infrastructure.
We suffix the PATH instead of prepend such that project versions of the
software takes precedence.
It's opt-in for now to but worth revisiting later for the previous
reasons.

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

@@ -170,12 +170,24 @@ in
   '';
 
   nvim_with_autoconfigure = pkgs.neovim.overrideAttrs(oa: {
-    plugins = [ vimPlugins.unicode-vim ];
+    plugins = [
+      vimPlugins.unicode-vim
+      vimPlugins.fzf-hoogle-vim
+    ];
     autoconfigure = true;
     # legacy wrapper sets it to false
     wrapRc = true;
   });
 
+  nvim_with_runtimeDeps = pkgs.neovim.overrideAttrs({
+    plugins = [
+      pkgs.vimPlugins.hex-nvim
+    ];
+    autowrapRuntimeDeps = true;
+    # legacy wrapper sets it to false
+    wrapRc = true;
+  });
+
   nvim_with_ftplugin = let
     # this plugin checks that it's ftplugin/vim.tex is loaded before $VIMRUNTIME/ftplugin/vim.tex
     # $VIMRUNTIME/ftplugin/vim.tex sources $VIMRUNTIME/ftplugin/initex.vim which sets b:did_ftplugin
@@ -334,7 +346,6 @@ in
     ${nvim_with_opt_plugin}/bin/nvim -i NONE +quit! -e
   '';
 
-  inherit nvim-with-luasnip;
 
   autoconfigure = runTest nvim_with_autoconfigure ''
       assertFileContains \
@@ -342,11 +353,18 @@ in
         '${vimPlugins.unicode-vim.passthru.initLua}'
   '';
 
+  autowrap_runtime_deps = runTest nvim_with_runtimeDeps ''
+      assertFileContains \
+        "${nvim_with_runtimeDeps}/bin/nvim" \
+        '${pkgs.xxd}/bin'
+  '';
+
+  inherit nvim-with-luasnip;
   # check that bringing in one plugin with lua deps makes those deps visible from wrapper
   # for instance luasnip has a dependency on jsregexp
   can_require_transitive_deps =
     runTest nvim-with-luasnip ''
-    cat ${nvim-with-luasnip}/bin/nvim
+    cat ${nvim-with-luasnip}/nvim
     ${nvim-with-luasnip}/bin/nvim -i NONE --cmd "lua require'jsregexp'" -e +quitall!
   '';
 

pkgs/applications/editors/neovim/wrapper.nix

@@ -24,6 +24,10 @@ let
     # to work with nix.
     # if true, the wrapper automatically appends those snippets when necessary
     , autoconfigure ? false
+
+    # append to PATH runtime deps of plugins
+    , autowrapRuntimeDeps ? false
+
     # should contain all args but the binary. Can be either a string or list
     , wrapperArgs ? []
     , withPython2 ? false
@@ -120,7 +124,15 @@ let
     wrapperArgsStr = if lib.isString wrapperArgs then wrapperArgs else lib.escapeShellArgs wrapperArgs;
 
     generatedWrapperArgs = let
-      binPath = lib.makeBinPath (lib.optional finalAttrs.withRuby rubyEnv ++ lib.optional finalAttrs.withNodeJs nodejs);
+      op = acc: normalizedPlugin: acc ++ normalizedPlugin.plugin.runtimeDeps or [];
+
+      runtimeDeps = lib.foldl' op [] pluginsNormalized;
+
+      binPath = lib.makeBinPath (
+           lib.optional finalAttrs.withRuby rubyEnv
+        ++ lib.optional finalAttrs.withNodeJs nodejs
+        ++ lib.optionals finalAttrs.autowrapRuntimeDeps runtimeDeps
+        );
     in
 
       # vim accepts a limited number of commands so we join them all
@@ -167,7 +179,7 @@ let
       __structuredAttrs = true;
       dontUnpack = true;
       inherit viAlias vimAlias withNodeJs withPython3 withPerl withRuby;
-      inherit autoconfigure wrapRc providerLuaRc packpathDirs;
+      inherit autoconfigure autowrapRuntimeDeps wrapRc providerLuaRc packpathDirs;
       inherit python3Env rubyEnv;
       inherit wrapperArgs generatedWrapperArgs;
       luaRcContent = rcContent;

pkgs/applications/editors/vim/plugins/overrides.nix

@@ -1285,9 +1285,7 @@ in
   };
 
   hex-nvim = super.hex-nvim.overrideAttrs {
-    postPatch = ''
+    runtimeDeps = [ xxd ];
-      substituteInPlace lua/hex.lua --replace xxd ${xxd}/bin/xxd
-    '';
     nvimRequireCheck = "hex";
   };