add length, minLength, maxLength to array

README.md

@@ -87,7 +87,7 @@ A string validator that matches a regex (regex can optionally be passed in as a
 s.String({ regex: /h[ae]llo world/ });
 ```
 
-### s.Array { opt: false }
+### s.Array { opt: false, length: null, minLength: null, maxLength: null }
 
 An array validator which can only contain Dates.
 ```javascript

test/array.js

@@ -57,4 +57,42 @@ describe("Array validator", function() {
         assert.deepEqual(schema.validate(messyArray), messyArray);
     });
 
+    it("should accept length option", function() {
+
+        var schema = s.Array({ length: 5 }, [ s.Number() ]);
+
+        assert.throws(function() {
+            schema.validate([ 1, 2, 3, 4 ]);
+        });
+
+        assert.deepEqual(schema.validate([ 1, 2, 3, 4, 5 ]), [ 1, 2, 3, 4, 5 ]);
+
+    });
+
+    it("should accept minLength option", function() {
+
+        var schema = s.Array({ minLength: 3 }, [ s.Number() ]);
+
+        assert.throws(function() {
+            schema.validate([ 1, 2 ]);
+        });
+
+        assert.deepEqual(schema.validate([ 1, 2, 3 ]), [ 1, 2, 3 ]);
+        assert.deepEqual(schema.validate([ 1, 2, 3, 4, 5, 6, 7 ]), [ 1, 2, 3, 4, 5, 6, 7 ]);
+
+    });
+
+    it("should accept maxLength option", function() {
+
+        var schema = s.Array({ maxLength: 3 }, [ s.Number() ]);
+
+        assert.throws(function() {
+            schema.validate([ 1, 2, 3, 4 ]);
+        });
+
+        assert.deepEqual(schema.validate([ 1 ]), [ 1 ]);
+        assert.deepEqual(schema.validate([ 1, 2, 3 ]), [ 1, 2, 3 ]);
+
+    });
+
 });

validators/array.js

@@ -14,6 +14,18 @@ function arrayParser(args, childValidators, data, key) {
         throw new Error("required Array");
     }
 
+    if(typeof args.length == 'number' && data.length !== args.length) {
+        throw new Error("required array with " + args.length + " items, got: " + data.length);
+    }
+
+    if(typeof args.minLength == 'number' && data.length < args.minLength) {
+        throw new Error("required array wtith minimum " + args.length + " items, got: " + data.length);
+    }
+
+    if(typeof args.maxLength == 'number' && data.length > args.maxLength) {
+        throw new Error("required array with maximum " + args.length + " items, got: " + data.length);
+    }
+
     for(var i = 0; i < data.length; i++) {
 
         var val     = data[i];