add assertions isDivisibleByFive and containsFive

README.md

@@ -147,6 +147,12 @@ five.base(3); // 12
 ##### Assertion
 ```javascript
 five.isFive(10); // false
+five.isDivisibleByFive(8); // false
+five.isDivisibleByFive(15); // true
+five.containsFive(154); // true
+five.containsFive('this string contains 5, or not?'); // true
+five.containsFive([ 2, 5, 17 ]); // true
+five.containsFive([ 8, 14, 53 ]); // true
 ```
 
 ##### Filter, Map and Reduce

five.js

@@ -135,6 +135,21 @@
   five.high = function() { return "o/"; };
 
   five.isFive = function(a) { return a === five(); };
+
+  five.isDivisibleByFive = function(number) {
+    if (typeof number !== 'number') return false;
+    return number % five() === 0;
+  };
+
+  five.containsFive = function(candidate) {
+    if (!candidate) return false;
+
+    if (Object.prototype.toString.call(candidate) === '[object Array]') {
+      candidate = candidate.map(function(item) { return item.toString();}).join(' ');
+    }
+
+    return candidate.toString().indexOf('5') !== -1;
+  }
 
   five.map = function(array) { return array.map(five); };
   five.filter = function(array) { return array.filter(five.isFive); };

test.js

@@ -132,6 +132,22 @@ assert.equal(five.funk(), '5 bad boys with the power to rock you', 'A funked fiv
 assert.equal(true, five.isFive(five()));
 assert.equal(false, five.isFive(10));
 
+assert.equal(false, five.isDivisibleByFive('foo'));
+assert.equal(true, five.isDivisibleByFive(five()));
+assert.equal(true, five.isDivisibleByFive(10));
+assert.equal(false, five.isDivisibleByFive(42));
+
+assert.equal(true, five.containsFive(153));
+assert.equal(true, five.containsFive('this string contains number 5, for sure!'));
+assert.equal(true, five.containsFive([1, 6, 15, 3]));
+assert.equal(false, five.containsFive());
+assert.equal(false, five.containsFive(null));
+assert.equal(false, five.containsFive(''));
+assert.equal(false, five.containsFive(false));
+assert.equal(false, five.containsFive(143));
+assert.equal(false, five.containsFive('this string does not contain...'));
+assert.equal(false, five.containsFive([1, 6, 8, 3]));
+
 assert.equal(JSON.stringify([5, 5]), JSON.stringify(five.filter([5, true, 5])));
 assert.equal(JSON.stringify([5, 5, 5]), JSON.stringify(five.map([1, 2, 3])));
 assert.equal(5, five.reduce([1, 2, 3]));