wimlib: add more comprehensive test

Closes Homebrew/homebrew#38275.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Formula/wimlib.rb

@@ -31,6 +31,16 @@ class Wimlib < Formula
   end
 
   test do
-    system bin/"wiminfo", "--help"
+    # make a directory containing a dummy 1M file
+    mkdir("foo")
+    system "dd", "if=/dev/random", "of=foo/bar", "bs=1m", "count=1"
+
+    # capture an image
+    ENV.append "WIMLIB_IMAGEX_USE_UTF8", "1"
+    system "#{bin}/wimcapture", "foo", "bar.wim"
+    assert File.exist?("bar.wim")
+
+    # get info on the image
+    system "#{bin}/wiminfo", "bar.wim"
   end
 end