wdiff: add test

Closes #28382.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/Library/Formula/wdiff.rb b/Library/Formula/wdiff.rb
index 9e6106eae..80874a4ab 100644
--- a/Library/Formula/wdiff.rb
+++ b/Library/Formula/wdiff.rb
@@ -14,4 +14,16 @@ class Wdiff < Formula
                           "--enable-experimental"
     system "make install"
   end
+
+  test do
+    a = testpath/"a.txt"
+    a.write "The missing package manager for OS X"
+
+    b = testpath/"b.txt"
+    b.write "The package manager for OS X"
+
+    out = `#{bin}/wdiff #{a} #{b}`
+    assert_equal "The [-missing-] package manager for OS X", out
+    assert_equal 1, $?.exitstatus
+  end
 end