Use clean.layers to determine types

This allows removing the types middleware and simplifies some code.

controller/search.js

@@ -11,7 +11,6 @@ function setup( backend, query ){
     // do not run controller when a request
     // validation error has occurred.
     if( req.errors && req.errors.length ){
-      delete req.clean.type; //to declutter output
       return next();
     }
 
@@ -25,12 +24,9 @@ function setup( backend, query ){
       body: query( req.clean )
     };
 
-    // set the Elasticsearch types to filter by,
-    // and remove the property from clean so the API
-    // response output is cleaner
-    if( req.clean.hasOwnProperty('type') ){
-      cmd.type = req.clean.type;
-      delete req.clean.type;
+    // use layers field for filtering by type
+    if( req.clean.hasOwnProperty('layers') ){
+      cmd.type = req.clean.layers;
     }
 
     logger.debug( '[ES req]', JSON.stringify(cmd) );

middleware/_types.js

@@ -1,18 +0,0 @@
-/**
- * Take the layers specified by the layers parameter and use them to set the
- * list of Elasticsearch types to filter.
- *
- * This has to be done outside the layers sanitizer since it doesn't know that
- * the layers property is eventualy used to choose the _type.
- */
-function middleware(req, res, next) {
-  req.clean = req.clean || {};
-
-  if (req.clean.hasOwnProperty('layers')) {
-    req.clean.type = req.clean.layers;
-  }
-
-  next();
-}
-
-module.exports = middleware;

routes/v1.js

@@ -12,7 +12,6 @@ var sanitisers = {
 
 /** ----------------------- middleware ------------------------ **/
 var middleware = {
-  types: require('../middleware/_types'),
   calcSize: require('../middleware/sizeCalculator')
 };
 
@@ -59,7 +58,6 @@ function addRoutes(app, peliasConfig) {
     ]),
     search: createRouter([
       sanitisers.search.middleware,
-      middleware.types,
       middleware.calcSize(),
       controllers.search(),
       postProc.distances('focus.point.'),
@@ -72,7 +70,6 @@ function addRoutes(app, peliasConfig) {
     ]),
     autocomplete: createRouter([
       sanitisers.autocomplete.middleware,
-      middleware.types,
       controllers.search(null, require('../query/autocomplete')),
       postProc.distances('focus.point.'),
       postProc.confidenceScores(peliasConfig),
@@ -84,7 +81,6 @@ function addRoutes(app, peliasConfig) {
     ]),
     reverse: createRouter([
       sanitisers.reverse.middleware,
-      middleware.types,
       middleware.calcSize(),
       controllers.search(undefined, reverseQuery),
       postProc.distances('point.'),