add tests for kray util

Author: mauk81

test/index.html

@@ -72,6 +72,8 @@
     <script src="kpoint.js"></script>
     <script src="../utils/kline.js"></script>
     <script src="kline.js"></script>
+    <script src="../utils/kray.js"></script>
+    <script src="kray.js"></script>
     <script src="../utils/answer-types.js"></script>
     <script src="answer-types.js"></script>
     <script src="../utils/rational-expressions.js"></script>

test/kray.js

@@ -0,0 +1,30 @@
+(function() {
+    module("kray");
+
+    var ray = KhanUtil.kray;
+
+    asyncTest('two identical rays should be equal', 1, function() {
+        var result = ray.equal([[0, 0], [1, 0]], [[0, 0], [2, 0]]);
+        strictEqual(result, true);
+        start();
+    });
+
+    asyncTest('two rays with different directions should not be equal', 1, function() {
+        var result = ray.equal([[0, 0], [1, 0]], [[0, 0], [0, 1]]);
+        strictEqual(result, false);
+        start();
+    });
+
+    asyncTest('two parallel rays should not be equal', 1, function() {
+        var result = ray.equal([[0, 0], [1, 0]], [[0, 1], [1, 1]]);
+        strictEqual(result, false);
+        start();
+    });
+
+    asyncTest('two rays with different endpoint should not be equal', 1, function() {
+        var result = ray.equal([[0, 0], [2, 0]], [[1, 0], [2, 0]]);
+        strictEqual(result, false);
+        start();
+    });
+
+})();