dive: add shell completion (#414102)

pkgs/by-name/di/dive/package.nix

@@ -4,6 +4,7 @@
   buildGoModule,
   fetchFromGitHub,
   pkg-config,
+  installShellFiles,
   btrfs-progs,
   gpgme,
   lvm2,
@@ -21,7 +22,10 @@ buildGoModule rec {
 
   vendorHash = "sha256-egsFnnHZMPRTJeFw6uByE9OJH06zqKRTvQi9XhegbDI=";
 
-  nativeBuildInputs = [ pkg-config ];
+  nativeBuildInputs = [
+    pkg-config
+    installShellFiles
+  ];
 
   buildInputs = lib.optionals stdenv.hostPlatform.isLinux [
     btrfs-progs
@@ -35,6 +39,13 @@ buildGoModule rec {
     "-X main.version=${version}"
   ];
 
+  postInstall = lib.optionalString (stdenv.buildPlatform.canExecute stdenv.hostPlatform) ''
+    installShellCompletion --cmd dive \
+      --bash <($out/bin/dive completion bash) \
+      --fish <($out/bin/dive completion fish) \
+      --zsh <($out/bin/dive completion zsh)
+  '';
+
   meta = {
     description = "Tool for exploring each layer in a docker image";
     mainProgram = "dive";