Add Oolong.property.

Author: moll

CHANGELOG.md

@@ -1,3 +1,8 @@
+## Unreleased
+- Adds [`Oolong.property`][property].
+
+[property]: https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.property
+
 ## 1.12.0 (Jun 26, 2015)
 - Adds [`Oolong.setPrototypeOf`][setPrototypeOf].
 

README.md

@@ -65,6 +65,7 @@ For extended documentation on all functions, please see the
 - [.mapKeys](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.mapKeys)(object, callback, [thisArg])
 - [.merge](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.merge)(target, source...)
 - [.ownKeys](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.ownKeys)(object)
+- [.property](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.property)(key)
 - [.reject](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.reject)(object, callback, [thisArg])
 - [.setPrototypeOf](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.setPrototypeOf)(object, prototype)
 - [.values](https://github.com/moll/js-oolong/blob/master/doc/API.md#Oolong.values)(object)

doc/API.md

@@ -28,6 +28,7 @@ Oolong.js API Documentation
 - [.mapKeys](#Oolong.mapKeys)(object, callback, [thisArg])
 - [.merge](#Oolong.merge)(target, source...)
 - [.ownKeys](#Oolong.ownKeys)(object)
+- [.property](#Oolong.property)(key)
 - [.reject](#Oolong.reject)(object, callback, [thisArg])
 - [.setPrototypeOf](#Oolong.setPrototypeOf)(object, prototype)
 - [.values](#Oolong.values)(object)
@@ -407,6 +408,16 @@ person.age = 42
 Oolong.ownKeys(person) // => ["age"]
 ```
 
+<a name="Oolong.property" />
+### Oolong.property(key)
+Returns a function that returns the given property of an object.
+
+**Examples**:
+```javascript
+var getName = Oolong.property("name")
+getName({name: "John"}) // => "John
+```
+
 <a name="Oolong.reject" />
 ### Oolong.reject(object, callback, [thisArg])
 Rejects all enumerable properties and returns a new object without those

index.js

@@ -593,6 +593,21 @@ exports.merge = function merge(target) {
  */
 exports.ownKeys = Object.keys
 
+/**
+ * Returns a function that returns the given property of an object.
+ *
+ * @example
+ * var getName = Oolong.property("name")
+ * getName({name: "John"}) // => "John
+ *
+ * @static
+ * @method property
+ * @param key
+ */
+exports.property = function(key) {
+  return function(obj) { return obj[key] }
+}
+
 /**
  * Rejects all enumerable properties and returns a new object without those
  * properties for which the given function returned truthy for.  

test/oolong/property_test.js

@@ -0,0 +1,13 @@
+var $ = require("../..")
+
+describe("Oolong.property", function() {
+  it("must return a function that returns the given property", function() {
+    var obj = {name: "John"}
+    $.property("name")(obj).must.equal("John")
+  })
+
+  it("must return inherited properties", function() {
+    var obj = Object.create({name: "John"})
+    $.property("name")(obj).must.equal("John")
+  })
+})