[evgeny, pawel] compareProperty function

Author: Evgeny Poberezkin

README.md

@@ -135,4 +135,5 @@ Functions
   * [result](http://mailonline.github.io/proto/proto_util.js.html#result)
   * [identity](http://mailonline.github.io/proto/proto_util.js.html#identity)
   * [property](http://mailonline.github.io/proto/proto_util.js.html#property)
+  * [compareProperty](http://mailonline.github.io/proto/proto_util.js.html#compareProperty)
   * [noop](http://mailonline.github.io/proto_util.js.html#noop)

bower.json

@@ -1,6 +1,6 @@
 {
   "name": "proto",
-  "version": "0.1.10",
+  "version": "0.1.11",
   "homepage": "https://github.com/MailOnline/proto",
   "authors": [
     "MOL Technical <[email protected]>"

lib/proto.js

@@ -118,6 +118,7 @@ var numberMethods = require('./proto_number');
  * - [result](proto_util.js.html#result)
  * - [identity](proto_util.js.html#identity)
  * - [property](proto_util.js.html#property)
+ * - [compareProperty](proto_util.js.html#compareProperty)
  * - [noop](proto_util.js.html#noop)
  */
 var utilMethods = require('./proto_util');

lib/proto_util.js

@@ -7,6 +7,7 @@
  * - [result](#result)
  * - [identity](#identity)
  * - [property](#property)
+ * - [compareProperty](#compareProperty)
  * - [noop](#noop)
  */
 var utilMethods = module.exports = {
@@ -16,6 +17,7 @@ var utilMethods = module.exports = {
     result: result,
     identity: identity,
     property: property,
+    compareProperty: compareProperty,
     noop: noop
 };
 
@@ -104,6 +106,24 @@ function property() {
 }
 
 
+/**
+ * Returns function that can be used in array sort to sort by a given property
+ *
+ * @param {String} self
+ * @return {Function}
+ */
+function compareProperty() {
+    var key = this;
+    return function(a, b) {
+        return a[key] < b[key]
+            ? -1
+            : a[key] > b[key]
+                ? 1
+                : 0;
+    };
+}
+
+
 /**
  * Function that does nothing
  */

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mol-proto",
-  "version": "0.1.10",
+  "version": "0.1.11",
   "description": "ES5 object manipulation library for node and modern browsers",
   "main": "lib/proto.js",
   "scripts": {

test/proto_util_test.js

@@ -70,4 +70,30 @@ describe('Utility functions', function() {
         assert.equal(p1(obj), 1);
         assert.equal(p2(obj), 2);
     });
+
+
+    it('should define compareProperty function', function() {
+        var arr = [
+            { value: 1, label: 'a'},
+            { value: 4, label: 'c'},
+            { value: 3, label: 'd'},
+            { value: 2, label: 'b'}
+        ];
+
+        arr.sort(_.compareProperty('value'));
+        assert.deepEqual(arr, [
+            { value: 1, label: 'a'},
+            { value: 2, label: 'b'},
+            { value: 3, label: 'd'},
+            { value: 4, label: 'c'}
+        ]);
+
+        arr.sort(_.compareProperty('label'));
+        assert.deepEqual(arr, [
+            { value: 1, label: 'a'},
+            { value: 2, label: 'b'},
+            { value: 4, label: 'c'},
+            { value: 3, label: 'd'}
+        ]);
+    });
 });