nix-index: add module (#1984)

`nix-index` is a tool to quickly locate the package providing a certain
file in `nixpkgs`. It indexes built derivations found in binary caches.

This module adds the shell integration for its `command-not-found`
script for interactive shells.

.github/CODEOWNERS

@@ -113,6 +113,9 @@
 /modules/programs/newsboat.nix                        @sumnerevans
 /tests/modules/programs/newsboat                      @sumnerevans
 
+/modules/programs/nix-index.nix                       @ambroisie
+/tests/modules/programs/nix-index                     @ambroisie
+
 /modules/programs/noti.nix                            @marsam
 
 /modules/programs/nushell.nix                         @Philipp-M

modules/lib/maintainers.nix

@@ -81,4 +81,10 @@
       fingerprint = "8F87 050B 0F9C B841 1515  7399 B784 3F82 3355 E9B9";
     }];
   };
+  ambroisie = {
+    email = "bruno.home-manager@belanyi.fr";
+    github = "ambroisie";
+    githubId = 12465195;
+    name = "Bruno BELANYI";
+  };
 }

modules/misc/news.nix

@@ -1973,6 +1973,13 @@ in
           A new module is available: 'services.etesync-dav'
         '';
       }
+
+      {
+        time = "2021-05-06T11:01:41+00:00";
+        message = ''
+          A new module is available: 'programs.nix-index'.
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -103,6 +103,7 @@ let
     (loadModule ./programs/neomutt.nix { })
     (loadModule ./programs/neovim.nix { })
     (loadModule ./programs/newsboat.nix { })
+    (loadModule ./programs/nix-index.nix { })
     (loadModule ./programs/noti.nix { })
     (loadModule ./programs/notmuch.nix { })
     (loadModule ./programs/nushell.nix { })

modules/programs/nix-index.nix

@@ -0,0 +1,63 @@
+{ config, lib, pkgs, ... }:
+let cfg = config.programs.nix-index;
+in {
+  meta.maintainers = with lib.hm.maintainers; [ ambroisie ];
+
+  options.programs.nix-index = with lib; {
+    enable = mkEnableOption "nix-index, a file database for nixpkgs";
+
+    package = mkOption {
+      type = types.package;
+      default = pkgs.nix-index;
+      defaultText = literalExample "pkgs.nix-index";
+      description = "Package providing the <command>nix-index</command> tool.";
+    };
+
+    enableBashIntegration = mkEnableOption "Bash integration" // {
+      default = true;
+    };
+
+    enableZshIntegration = mkEnableOption "Zsh integration" // {
+      default = true;
+    };
+
+    enableFishIntegration = mkEnableOption "Fish integration" // {
+      default = true;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = let
+      checkOpt = name: {
+        assertion = cfg.${name} -> !config.programs.command-not-found.enable;
+        message = ''
+          The 'programs.command-not-found.enable' option is mutually exclusive
+          with the 'programs.nix-index.${name}' option.
+        '';
+      };
+    in [ (checkOpt "enableBashIntegration") (checkOpt "enableZshIntegration") ];
+
+    home.packages = [ cfg.package ];
+
+    programs.bash.initExtra = lib.mkIf cfg.enableBashIntegration ''
+      source ${cfg.package}/etc/profile.d/command-not-found.sh
+    '';
+
+    programs.zsh.initExtra = lib.mkIf cfg.enableZshIntegration ''
+      source ${cfg.package}/etc/profile.d/command-not-found.sh
+    '';
+
+    # See https://github.com/bennofs/nix-index/issues/126
+    programs.fish.shellInit = let
+      wrapper = pkgs.writeScript "command-not-found" ''
+        #!${pkgs.bash}/bin/bash
+        source ${cfg.package}/etc/profile.d/command-not-found.sh
+        command_not_found_handle "$@"
+      '';
+    in lib.mkIf cfg.enableFishIntegration ''
+      function __fish_command_not_found_handler --on-event fish_command_not_found
+          ${wrapper} $argv
+      end
+    '';
+  };
+}

tests/default.nix

@@ -65,6 +65,7 @@ import nmt {
     ./modules/programs/ne
     ./modules/programs/neomutt
     ./modules/programs/newsboat
+    ./modules/programs/nix-index
     ./modules/programs/nushell
     ./modules/programs/pet
     ./modules/programs/powerline-go

tests/modules/programs/nix-index/assert-on-command-not-found.nix

@@ -0,0 +1,26 @@
+{ pkgs, ... }: {
+  config = {
+    programs.bash.enable = true;
+    programs.fish.enable = true;
+    programs.zsh.enable = true;
+
+    programs.command-not-found.enable = true;
+
+    nixpkgs.overlays =
+      [ (self: super: { zsh = pkgs.writeScriptBin "dummy-zsh" ""; }) ];
+
+    programs.nix-index.enable = true;
+
+    # 'command-not-found' does not have a 'fish' integration
+    test.asserts.assertions.expected = [
+      ''
+        The 'programs.command-not-found.enable' option is mutually exclusive
+        with the 'programs.nix-index.enableBashIntegration' option.
+      ''
+      ''
+        The 'programs.command-not-found.enable' option is mutually exclusive
+        with the 'programs.nix-index.enableZshIntegration' option.
+      ''
+    ];
+  };
+}

tests/modules/programs/nix-index/default.nix

@@ -0,0 +1,4 @@
+{
+  nix-index-integrations = ./integrations.nix;
+  nix-index-assert-on-command-not-found = ./assert-on-command-not-found.nix;
+}

tests/modules/programs/nix-index/integrations.nix

@@ -0,0 +1,38 @@
+{ pkgs, ... }:
+let
+  fishRegex = ''
+    function __fish_command_not_found_handler --on-event fish_command_not_found
+        /nix/store/.*command-not-found $argv
+    end
+  '';
+in {
+  config = {
+    programs.bash.enable = true;
+    programs.fish.enable = true;
+    programs.zsh.enable = true;
+
+    nixpkgs.overlays =
+      [ (self: super: { zsh = pkgs.writeScriptBin "dummy-zsh" ""; }) ];
+
+    programs.nix-index.enable = true;
+
+    nmt.script = ''
+      # Bash integration
+      assertFileExists home-files/.bashrc
+      assertFileRegex \
+        home-files/.bashrc \
+        'source /nix/store/.*nix-index.*/etc/profile.d/command-not-found.sh'
+
+      # Zsh integration
+      assertFileExists home-files/.zshrc
+      assertFileRegex \
+        home-files/.zshrc \
+        'source /nix/store/.*nix-index.*/etc/profile.d/command-not-found.sh'
+
+      # Fish integration
+      assertFileExists home-files/.config/fish/config.fish
+      assertFileRegex \
+        home-files/.config/fish/config.fish '${fishRegex}'
+    '';
+  };
+}