Merge pull request #134 from Medium/kyle-inject-ctor

Modify .ctor to inject params

lib/NodeDefinition.js

@@ -576,6 +576,8 @@ NodeDefinition.prototype.fn = function (fn) {
  * @param {function(new:Object, ...)} Ctor
  */
 NodeDefinition.prototype.ctor = function (Ctor) {
+  this._setArgsFromFunction(Ctor)
+
   /** @constructor */
   function SubCtor(argList) {
     Ctor.apply(this, argList)
@@ -596,17 +598,28 @@ NodeDefinition.prototype.ctor = function (Ctor) {
  * @param {!Function} fn
  */
 NodeDefinition.prototype.inject = function (fn) {
+  this._setArgsFromFunction(fn)
+  return this.fn(fn)
+}
+
+/**
+ * Re-arrange the node params from the function definition
+ *
+ * If the parameters can't be found, this will throw an error.
+ *
+ * @param {!Function} fn
+ */
+NodeDefinition.prototype._setArgsFromFunction = function (fn) {
   var paramNames = utils.parseFnParams(fn)
 
-  var shortArgsNames = []
-  var i = 0
-  for (i = 0; i < this._args.length; i++) {
-    shortArgsNames.push(utils.getNodeInjectorName(this._args[i].aliasRealName))
-  }
+  var shortArgsNames = this._args.map(function (arg) {
+    return utils.getNodeInjectorName(arg.aliasRealName)
+  })
 
-  // Sort the arguments  so that the parameters get injected in the
+  // Sort the arguments so that the parameters get injected in the
   // right order.
   var newArgs = []
+  var i
   for (i = 0; i < paramNames.length; i++) {
     var idx = shortArgsNames.indexOf(paramNames[i])
     if (idx === -1) {
@@ -621,8 +634,6 @@ NodeDefinition.prototype.inject = function (fn) {
   // Push any args that are not included.
   newArgs.push.apply(newArgs, this._args)
   this._args = newArgs
-
-  return this.fn(fn)
 }
 
 /**

package.json

@@ -1,7 +1,7 @@
 {
   "name": "shepherd",
   "description": "asynchronous dependency injection for node.js",
-  "version": "2.4.2",
+  "version": "2.5.0",
   "homepage": "https://github.com/Medium/shepherd",
   "authors": [
     "Jeremy Stanley <[email protected]> (https://github.com/azulus)",

test/builder.js

@@ -463,3 +463,26 @@ builder.add(function testContructor(test) {
     test.equal(2, myType.b)
   })
 })
+
+
+builder.add(function testContructorInjects(test) {
+  function MyType(a, b) {
+    this.a = a
+    this.b = b
+  }
+
+  graph.add('myType')
+    .args('b', 'c', 'a')
+    .ctor(MyType)
+
+  return graph.newBuilder()
+      .builds('myType')
+        .using({'a': graph.literal(1)}, {'b': graph.literal(2)}, {'c': graph.literal(3)})
+      .run()
+  .then(function (data) {
+    var myType = data['myType']
+    test.ok(myType instanceof MyType)
+    test.equal(1, myType.a)
+    test.equal(2, myType.b)
+  })
+})