write `expect` macro for ease of testing. first test passes

rover.fnl

@@ -1,9 +1,42 @@
 (local { : view } (require :fennel))
 
+(macro expect [text actual expected]
+  `(let [actual# ,actual]
+     (or (match actual#
+           ,expected true
+           _# false)
+         (assert false (view {
+                         :text ,text
+                         :expected ,expected
+                         :actual actual#
+                         })))))
+
+(fn command [rover commands]
+  {:x 0 :y 1 :direction :n})
+
 (fn rover [x y direction]
-  {})
+  {: x
+   : y
+   : direction
+   : command
+   })
 
 (let [r (rover 0 0 :n)]
-  (match r
-    {:x 0 :y 0 :direction :n} true
-    _ (assert false (view r))))
+  (expect
+   "rover knows (x,y) and the direction (N,S,E,W) it is facing"
+   r
+   {:x 0 :y 0 :direction :n}))
+
+(let [r (rover 0 0 :n)]
+  (expect "The rover receives a character array of commands"
+          (r:command [:f :f :f])
+          {}))
+
+(let [r (rover 0 0 :n)]
+  (expect
+   "Moves north when pointing north and asked to move forward"
+   (r:command [:f])
+   {:x 0 :y 1 :direction :n}))
+
+
+(print "OK")