rest middleware: clean up context config

Modify `loopback.rest()` to read the configuration for
`loopback.context` from `app.get('remoting')`, which is the approach
used for all other configuration options related to the REST transport.

lib/middleware/rest.js

@@ -22,33 +22,31 @@ module.exports = rest;
  * @header loopback.rest()
  */
 
-function rest(options) {
-  options = options || {};
-  var tokenParser = null;
-  var contextHandler = null;
-  if (options.context) {
-    var contextOptions = options.context;
-    if(typeof contextOptions !== 'object') {
-      contextOptions = {};
-    }
-    contextHandler = loopback.context(contextOptions);
-  }
+function rest() {
   return function restApiHandler(req, res, next) {
     var app = req.app;
-    var handler = app.handler('rest');
+    var restHandler = app.handler('rest');
 
     if (req.url === '/routes') {
-      return res.send(handler.adapter.allRoutes());
+      return res.send(restHandler.adapter.allRoutes());
     } else if (req.url === '/models') {
       return res.send(app.remotes().toJSON());
     }
 
-    var handlers = [];
-    if (options.context) {
-      handlers.push(contextHandler);
+    var preHandlers;
+
+    if (!preHandlers) {
+      preHandlers = [];
+      var remotingOptions = app.get('remoting') || {};
+
+      var contextOptions = remotingOptions.context;
+      if (contextOptions !== false) {
+        if (typeof contextOptions !== 'object')
+          contextOptions = {};
+        preHandlers.push(loopback.context(contextOptions));
       }
+
       if (app.isAuthEnabled) {
-      if (!tokenParser) {
         // NOTE(bajtos) It would be better to search app.models for a model
         // of type AccessToken instead of searching all loopback models.
         // Unfortunately that's not supported now.
@@ -56,12 +54,11 @@ function rest(options) {
         // https://github.com/strongloop/loopback/pull/167
         // https://github.com/strongloop/loopback/commit/f07446a
         var AccessToken = loopback.getModelByType(loopback.AccessToken);
-        tokenParser = loopback.token({ model: AccessToken });
-        handlers.push(tokenParser);
+        preHandlers.push(loopback.token({ model: AccessToken }));
       }
     }
-    handlers.push(handler);
-    async.eachSeries(handlers, function(handler, done) {
+
+    async.eachSeries(preHandlers.concat(restHandler), function(handler, done) {
       handler(req, res, done);
     }, next);
   };

test/rest.middleware.test.js

@@ -187,7 +187,8 @@ describe('loopback.rest', function() {
 
     it('should enable context with loopback.rest', function(done) {
       app.enableAuth();
-      app.use(loopback.rest({context: {enableHttpContext: true}}));
+      app.set('remoting', { context: { enableHttpContext: true } });
+      app.use(loopback.rest());
 
       invokeGetToken(done);
     });