Don't include undocumented commands in the manual

Author: edolstra

src/libcmd/include/nix/cmd/command.hh

@@ -24,7 +24,6 @@ static constexpr Command::Category catHelp = -1;
 static constexpr Command::Category catSecondary = 100;
 static constexpr Command::Category catUtility = 101;
 static constexpr Command::Category catNixInstallation = 102;
-static constexpr Command::Category catUndocumented = 103;
 
 static constexpr auto installablesCategory =
     "Options that change the interpretation of [installables](@docroot@/command-ref/new-cli/nix.md#installables)";

src/libutil/args.cc

@@ -671,6 +671,8 @@ nlohmann::json MultiCommand::toJSON()
         auto command = commandFun();
         auto j = command->toJSON();
         auto cat = nlohmann::json::object();
+        if (command->category() == Command::catUndocumented)
+            continue;
         cat["id"] = command->category();
         cat["description"] = trim(categories[command->category()]);
         cat["experimental-feature"] = command->experimentalFeature();

src/libutil/include/nix/util/args.hh

@@ -374,6 +374,7 @@ struct Command : virtual public Args
     using Category = int;
 
     static constexpr Category catDefault = 0;
+    static constexpr Category catUndocumented = 1;
 
     virtual std::optional<ExperimentalFeature> experimentalFeature();
 

src/nix/main.cc

@@ -121,10 +121,10 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs, virtual RootArgs
         categories.clear();
         categories[catHelp] = "Help commands";
         categories[Command::catDefault] = "Main commands";
+        categories[Command::catUndocumented] = "Undocumented commands";
         categories[catSecondary] = "Infrequently used commands";
         categories[catUtility] = "Utility/scripting commands";
         categories[catNixInstallation] = "Commands for upgrading or troubleshooting your Nix installation";
-        categories[catUndocumented] = "Undocumented commands";
 
         addFlag({
             .longName = "help",