fastjar: add passthru tests

pkgs/by-name/fa/fastjar/package.nix

@@ -1,5 +1,6 @@
 {
   lib,
+  callPackage,
   fetchzip,
   stdenv,
   zlib,
@@ -28,6 +29,13 @@ stdenv.mkDerivation (finalAttrs: {
 
   doCheck = true;
 
+  passthru = {
+    tests = lib.packagesFromDirectoryRecursive {
+      inherit callPackage;
+      directory = ./tests;
+    };
+  };
+
   meta = {
     homepage = "https://savannah.nongnu.org/projects/fastjar/";
     description = "Fast Java archiver written in C";

pkgs/by-name/fa/fastjar/tests/version-fastjar.nix

@@ -0,0 +1,6 @@
+{ fastjar, testers }:
+
+testers.testVersion {
+  package = fastjar;
+  command = "fastjar --version";
+}

pkgs/by-name/fa/fastjar/tests/version-grepjar.nix

@@ -0,0 +1,6 @@
+{ fastjar, testers }:
+
+testers.testVersion {
+  package = fastjar;
+  command = "grepjar --version";
+}