add base optional object observe transformer

lib/6to5/file.js

@@ -37,12 +37,22 @@ File.helpers = [
   "typeof",
   "exports-wildcard",
   "extends",
-  "get"
+  "get",
+  "observe-delete",
+  "observe-get",
+  "observe-update",
+  "observe-notify",
+  "observe-create"
 ];
 
 File.excludeHelpersFromRuntime = [
   "async-to-generator",
-  "typeof"
+  "typeof",
+  "observe-delete",
+  "observe-get",
+  "observe-update",
+  "observe-notify",
+  "observe-create"
 ];
 
 File.normaliseOptions = function (opts) {

lib/6to5/transformation/templates/observe-create.js

@@ -0,0 +1,4 @@
+(function (obj, callback) {
+  global._6to5Obsevers = global._6to5Obsevers || [];
+  global._6to5Obsevers.push([obj, callback]);
+});

lib/6to5/transformation/templates/observe-delete.js

@@ -0,0 +1,3 @@
+(function () {
+
+})

lib/6to5/transformation/templates/observe-get.js

@@ -0,0 +1,3 @@
+(function () {
+
+})

lib/6to5/transformation/templates/observe-notify.js

@@ -0,0 +1,3 @@
+(function () {
+
+})

lib/6to5/transformation/templates/observe-update.js

@@ -0,0 +1,3 @@
+(function () {
+
+})

lib/6to5/transformation/transform.js

@@ -80,6 +80,7 @@ _.each({
   generators:                require("./transformers/es6-generators"),
   restParameters:            require("./transformers/es6-rest-parameters"),
 
+  objectObserve:             require("./transformers/optional-object-observe"),
   protoToAssign:             require("./transformers/optional-proto-to-assign"),
 
   _declarations:             require("./transformers/_declarations"),

lib/6to5/transformation/transformers/optional-object-observe.js

@@ -0,0 +1 @@
+exports.optional = true;

test/fixtures/transformation/optional-object-observe/options.json

@@ -0,0 +1,3 @@
+{
+  "optional": ["objectObserve"]
+}