sil: clean up a bit and add a test

- Add meta.mainProgram to be able to use nix run
- Run preInstall and postInstall hooks
- Test creation of the save directory in passthru.tests
- Fix some typos and misformatting
- Change prePatch to postPatch (as in the suggestion I got when adding
  sil-q)

pkgs/games/sil/default.nix

@@ -1,4 +1,6 @@
-{ lib, stdenv, fetchzip, ncurses, libX11, libXaw, libXt, libXext, libXmu, makeWrapper, writeScript, ... }:
+{ pkgs, lib, stdenv, fetchzip, ncurses, libX11, libXaw, libXt, libXext, libXmu
+, makeWrapper, writeScript }:
+
 let
   setup = writeScript "setup" ''
     mkdir -p "$ANGBAND_PATH"
@@ -25,7 +27,7 @@ stdenv.mkDerivation rec {
 
   makefile = "Makefile.std";
 
-  prePatch = ''
+  postPatch = ''
     # Allow usage of ANGBAND_PATH
     substituteInPlace config.h --replace "#define FIXED_PATHS" ""
   '';
@@ -41,30 +43,42 @@ stdenv.mkDerivation rec {
   NIX_CFLAGS_COMPILE = "-fcommon";
 
   installPhase = ''
-    # the makefile doesn't have a sensible install target, so we hav to do it ourselves
+    runHook preInstall
+
+    # the makefile doesn't have a sensible install target, so we have to do it ourselves
     mkdir -p $out/bin
     cp sil $out/bin/sil
-    # Wrap the program to set a user-local ANGBAND_PATH, and run the setup script to copy files into place
+
+    # Wrap the program to set a user-local ANGBAND_PATH, and run the setup script to copy files into place.
     # We could just use the options for a user-local save and scores dir, but it tried to write to the
     # lib directory anyway, so we might as well give everyone a copy
     wrapProgram $out/bin/sil \
-      --run "set -u" \
       --run "export ANGBAND_PATH=\$HOME/.sil" \
       --run "${setup} ${src}/Sil/lib"
+
+    runHook postInstall
   '';
 
+  passthru.tests = {
+    saveDirCreation = pkgs.runCommand "save-dir-creation" {} ''
+      HOME=$(pwd) ${lib.getExe pkgs.sil} --help
+      test -d .sil && touch $out
+    '';
+  };
+
   meta = {
-    description = "A rouge-like game set in the first age of Middle-earth";
+    description = "A rogue-like game set in the First Age of Middle-earth";
     longDescription = ''
-      A game of adventure set in the first age of Middle-earth, when the world still
-      rang with elven song and gleamed with dwarven mail.
+      A game of adventure set in the First Age of Middle-earth, when the world still
+      rang with Elven song and gleamed with Dwarven mail.
 
       Walk the dark halls of Angband.  Slay creatures black and fell.  Wrest a shining
       Silmaril from Morgoth’s iron crown.
     '';
     homepage = "http://www.amirrorclear.net/flowers/game/sil/index.html";
     license = lib.licenses.gpl2;
-    maintainers = [ lib.maintainers.michaelpj ];
+    maintainers = with lib.maintainers; [ michaelpj kenran ];
     platforms = lib.platforms.linux;
+    mainProgram = "sil";
   };
 }