Add test system

Write a test for the `write-xfdf` function.

Worked out how to create the test system from:

- https://lispcookbook.github.io/cl-cookbook/testing.html
- https://github.com/sjl/cl-digraph/blob/master/cl-digraph.test.asd
- https://github.com/fukamachi/dexador/blob/master/dexador-test.asd

Add the test string to the `write-xfdf` function to pass the test and
check that the test runner is set up correctly.

1 files changed, 17 insertions, 0 deletions

diff --git a/xfdf-test.asd b/xfdf-test.asd
new file mode 100644
index 0000000..9a5b0ab
--- /dev/null
+++ b/xfdf-test.asd
@@ -0,0 +1,17 @@
+(asdf:defsystem xfdf-test
+  :description "Test suite for xfdf"
+  :version "0.0.1"
+  :license "GPL-3.0-or-later"
+  :author "Teddy Wing"
+
+  :depends-on (:1am
+               :xfdf)
+
+  :components ((:module "test"
+                :serial t
+                :components ((:file "xfdf"))))
+
+  :perform (test-op
+             (op system)
+             ; (symbol-call :xfdf-test :run)
+             (symbol-call :1am :run)))