added tests for robot-tick

test/robotwar/exec_test.clj

@@ -1,4 +1,48 @@
 (ns robotwar.exec-test
+  (:refer-clojure :exclude [compile])
   (:require [clojure.test :refer :all]
-            [robotwar.exec :refer :all]))
+            (robotwar [create :refer :all]
+                      [exec :refer :all])))
 
+(def src-code " START 
+                    0 TO A
+                TEST 
+                    IF A > 2 GOTO START 
+                    GOSUB INCREMENT
+                    GOTO TEST 
+                    100 TO A 
+                INCREMENT 
+                    A + 1 TO A 
+                    ENDSUB 
+                    200 TO A ")
+
+(def initial-state (init-robot (compile src-code)))
+(def states (iterate tick-robot initial-state))
+(def nth-state #(nth states %))
+
+(deftest branching-test
+  (testing "comparison statement should cause jump in instr-ptr"
+    (is (= (:instr-ptr (nth-state 4))
+           5))))
+
+(deftest arithmetic-test
+  (testing "addition"
+    (is (= (:acc (nth-state 7))
+           1))))
+
+(deftest gosub-and-call-stack-test
+  (testing "gosub should move instr-ptr and add the return-ptr to the call stack"
+    (is (let [{:keys [instr-ptr call-stack]} (nth-state 5)]
+          (= [instr-ptr call-stack]
+             [9 [6]])))))
+          
+(deftest endsub-test
+  (testing "endsub pops instr-ptr off call stack and goes there"
+    (is (let [{:keys [instr-ptr call-stack]} (nth-state 9)]
+          (= [instr-ptr call-stack]
+             [6 []])))))
+
+(deftest push-test
+  (testing "pushing number to register"
+    (is (= (get-in (nth-state 8) [:registers "A"])
+           1))))