- add a very few simple test for sum.
  The very first is currently broken
diff --git a/testsuite/sum.tests b/testsuite/sum.tests
new file mode 100755
index 0000000..0993f03
--- /dev/null
+++ b/testsuite/sum.tests
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# unit test for sum.
+# Copyright 2007 by Bernhard Fischer
+# Licensed under GPL v2 or later, see file LICENSE for details.
+
+# AUDIT: Unit tests for sum
+
+. testing.sh
+
+# testing "test name" "options" "expected result" "file input" "stdin"
+#   file input will be file called "input"
+#   test can create a file "actual" instead of writing to stdout
+
+testing "sum -r file doesn't print file's name" \
+        "sum -r $0 | grep -c $0 && echo wrongly_printed_filename || echo yes" \
+	"0\nyes\n" "" ""
+testing "sum -r file file does print both names" \
+        "sum -r $0 $0 | grep -c $0 && echo yes || echo wrongly_omitted_filename" \
+	"2\nyes\n" "" ""
+testing "sum -s file does print file's name" \
+        "sum -s $0 | grep -c $0 && echo yes || echo wrongly_omitted_filename" \
+	"1\nyes\n" "" ""
+exit $FAILCOUNT