git-prole: add shell completions

pkgs/by-name/gi/git-prole/package.nix

@@ -1,12 +1,16 @@
 {
   lib,
+  stdenv,
+  buildPackages,
   fetchFromGitHub,
   rustPlatform,
   git,
-  bash,
   nix-update-script,
+  installShellFiles,
 }:
 let
+  emulatorAvailable = stdenv.hostPlatform.emulatorAvailable buildPackages;
+  emulator = stdenv.hostPlatform.emulator buildPackages;
   version = "0.5.3";
 in
 rustPlatform.buildRustPackage {
@@ -20,14 +24,32 @@ rustPlatform.buildRustPackage {
     hash = "sha256-QwLkByC8gdAnt6geZS285ErdH8nfV3vsWjMF4hTzq9Y=";
   };
 
+  buildFeatures = [ "clap_mangen" ];
+
   useFetchCargoVendor = true;
   cargoHash = "sha256-qghc8HtJfpTYXAwC2xjq8lLlCu419Ttnu/AYapkAulI=";
 
   nativeCheckInputs = [
     git
-    bash
   ];
 
+  nativeBuildInputs = [
+    installShellFiles
+  ];
+
+  postInstall = lib.optionalString emulatorAvailable ''
+    manpages=$(mktemp -d)
+    ${emulator} $out/bin/git-prole manpages "$manpages"
+    for manpage in "$manpages"/*; do
+      installManPage "$manpage"
+    done
+
+    installShellCompletion --cmd git-prole \
+      --bash <(${emulator} $out/bin/git-prole completions bash) \
+      --fish <(${emulator} $out/bin/git-prole completions fish) \
+      --zsh <(${emulator} $out/bin/git-prole completions zsh)
+  '';
+
   meta = {
     homepage = "https://github.com/9999years/git-prole";
     changelog = "https://github.com/9999years/git-prole/releases/tag/v${version}";