add utils test

test/utils-test.js

@@ -0,0 +1,62 @@
+var chai = require('chai');
+var expect = chai.expect;
+
+var utils = require('../src/utils');
+
+describe('utils', function() {
+  describe('tupleLessOrEqual', function() {
+    var lessEqual = utils.tupleLessOrEqual;
+
+    it('should work on 1-tuples', function() {
+      expect(lessEqual([0], [1])).to.be.true;
+      expect(lessEqual([1], [0])).to.be.false;
+      expect(lessEqual([0], [0])).to.be.true;
+    });
+
+    it('should work on 2-tuples', function() {
+      expect(lessEqual([0, 1], [0, 2])).to.be.true;
+      expect(lessEqual([0, 1], [0, 0])).to.be.false;
+      expect(lessEqual([0, 1], [1, 0])).to.be.true;
+    });
+  });
+
+  describe('tupleRangeOverlaps', function() {
+    var overlap = utils.tupleRangeOverlaps;
+    it('should work on 1-tuples', function() {
+      var ivs = [
+          [[0], [10]],
+          [[5], [15]],
+          [[-5], [5]],
+          [[-5], [4]]
+      ];
+      var empty = [[4], [3]];
+      expect(overlap(ivs[0], ivs[1])).to.be.true;
+      expect(overlap(ivs[0], ivs[2])).to.be.true
+      expect(overlap(ivs[1], ivs[3])).to.be.false
+
+      expect(overlap(ivs[0], empty)).to.be.false
+      expect(overlap(ivs[1], empty)).to.be.false
+      expect(overlap(ivs[2], empty)).to.be.false
+      expect(overlap(ivs[3], empty)).to.be.false
+    });
+
+    it('should work on 2-tuples', function() {
+      expect(overlap([[0, 0], [0, 10]],
+                     [[0, 5], [0, 15]])).to.be.true;
+      expect(overlap([[0, 0], [0, 10]],
+                     [[-1, 15], [0, 0]])).to.be.true;
+      expect(overlap([[0, 0], [0, 10]],
+                     [[-1, 15], [1, -15]])).to.be.true;
+      expect(overlap([[0, 0], [0, 10]],
+                     [[-1, 15], [0, -1]])).to.be.false;
+      expect(overlap([[0, 0], [0, 10]],
+                     [[-1, 15], [0, 0]])).to.be.true;
+      expect(overlap([[0, 0], [0, 10]],
+                     [[0, 10], [0, 11]])).to.be.true;
+      expect(overlap([[1, 0], [3, 10]],
+                     [[-1, 10], [2, 1]])).to.be.true;
+      expect(overlap([[3, 0], [3, 10]],
+                     [[-1, 10], [2, 1]])).to.be.false;
+    });
+  });
+});