feat: encase static method

Author: Jack Ellis

changelog.md

@@ -4,6 +4,7 @@ Change Log
 - if an option in the `properties` config is null, jpex will no longer throw an error
 - Passing `$options` into a `Jpex as a Service` service now works
 - `Jpex.register.service().bindToInstance()` allows you to bind dependencies to a service instance
+- `Jpex.$encase` method allos you to wrap a function with a number of dependencies
 
 ## 2.0.0  
 ### Features  

package.json

@@ -1,6 +1,6 @@
 {
   "name": "jpex",
-  "version": "2.0.0",
+  "version": "2.1.0",
   "description": "Javascript Prototype Extension",
   "main": "src/index.js",
   "directories": {

spec/class/encase.spec.js

@@ -0,0 +1,24 @@
+describe('encase', function(){
+  var Jpex;
+  beforeEach(function () {
+    Jpex = require('../../src').extend();
+  });
+
+  it('should encase a method with specified dependencies', function () {
+    Jpex.register.constant('FOO', 'injected');
+    const fn = Jpex.$encase([ 'FOO' ], (foo) => (bah) => (foo + bah));
+
+    const result = fn('provided');
+
+    expect(result).toBe('injectedprovided');
+  });
+
+  it('infers dependencies from function arguments', function () {
+    Jpex.register.constant('FOO', 'injected');
+    const fn = Jpex.$encase((FOO) => (bah) => (FOO + bah));
+
+    const result = fn('provided');
+
+    expect(result).toBe('injectedprovided');
+  });
+});

src/class/privates.js

@@ -61,6 +61,20 @@ function resolve(name, namedParameters) {
     resolver.resolve(this, name, namedParameters);
 }
 
+function encase(dependencies, fn) {
+  var self = this;
+  if (typeof dependencies === 'function') {
+    fn = dependencies;
+    dependencies = resolver.extractParameters(fn);
+  }
+  return function () {
+    var context = this;
+    var args = Array.prototype.slice.call(arguments);
+    var deps = self.$resolve(dependencies);
+    return fn.apply(context, deps).apply(context, args);
+  };
+}
+
 function clearCache(names) {
   names = names ? [].concat(names) : [];
   var key;
@@ -85,6 +99,9 @@ module.exports = function (Parent, Class, options) {
     $resolve : {
       value : resolve
     },
+    $encase: {
+      value: encase,
+    },
     $clearCache : {
       value : clearCache
     },