Create a custom error middleware to augment error info

lib/cartodb/controllers/map.js

@@ -56,28 +56,42 @@ MapController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.createGet.bind(this)
+        this.createGet.bind(this),
+        mapErrorMiddleware({
+            label: 'ANONYMOUS LAYERGROUP',
+            augmentError: true
+        })
     );
     app.post(
         app.base_url_mapconfig,
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.createPost.bind(this)
+        this.createPost.bind(this),
+        mapErrorMiddleware({
+            label: 'ANONYMOUS LAYERGROUP',
+            augmentError: true
+        })
     );
     app.get(
         app.base_url_templated + '/:template_id/jsonp',
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.jsonp.bind(this)
+        this.jsonp.bind(this),
+        mapErrorMiddleware({
+            label: 'NAMED MAP LAYERGROUP'
+        })
     );
     app.post(
         app.base_url_templated + '/:template_id',
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.instantiate.bind(this)
+        this.instantiate.bind(this),
+        mapErrorMiddleware({
+            label: 'NAMED MAP LAYERGROUP'
+        })
     );
     app.options(app.base_url_mapconfig, cors('Content-Type'));
 };
@@ -170,7 +184,7 @@ MapController.prototype.create = function(req, res, prepareConfigFn, next) {
         function createLayergroup(err, requestMapConfig) {
             assert.ifError(err);
             var datasource = context.datasource || Datasource.EmptyDatasource();
-            mapConfig = new MapConfig(requestMapConfig, datasource);
+            res.locals.mapconfig = mapConfig = new MapConfig(requestMapConfig, datasource);
             self.mapBackend.createLayergroup(
                 mapConfig,
                 res.locals,
@@ -181,7 +195,6 @@ MapController.prototype.create = function(req, res, prepareConfigFn, next) {
         function afterLayergroupCreate(err, layergroup) {
             assert.ifError(err);
 
-            res.locals.mapconfig = mapConfig;
             res.locals.analysesResults = context.analysesResults;
             res.locals.layergroup = layergroup;
             res.locals.context = context;
@@ -194,8 +207,6 @@ MapController.prototype.create = function(req, res, prepareConfigFn, next) {
         },
         function finish(err) {
             if (err) {
-                err = Number.isFinite(err.layerIndex) ? populateError(err, mapConfig) : err;
-                err.label = 'ANONYMOUS LAYERGROUP';
                 return next(err);
             }
 
@@ -212,25 +223,6 @@ MapController.prototype.create = function(req, res, prepareConfigFn, next) {
     );
 };
 
-function populateError(err, mapConfig) {
-    var error = new Error(err.message);
-    error.http_status = err.http_status;
-
-    if (!err.http_status && err.message.indexOf('column "the_geom_webmercator" does not exist') >= 0) {
-        error.http_status = 400;
-    }
-
-    error.type = 'layer';
-    error.subtype = err.message.indexOf('Postgis Plugin') >= 0 ? 'query' : undefined;
-    error.layer = {
-        id: mapConfig.getLayerId(err.layerIndex),
-        index: err.layerIndex,
-        type: mapConfig.layerType(err.layerIndex)
-    };
-
-    return error;
-}
-
 MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn, next) {
     var self = this;
 
@@ -260,7 +252,7 @@ MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn
         },
         function createLayergroup(err, mapConfig_, rendererParams) {
             assert.ifError(err);
-            mapConfig = mapConfig_;
+            res.locals.mapconfig = mapConfig = mapConfig_;
             self.mapBackend.createLayergroup(
                 mapConfig, rendererParams,
                 new CreateLayergroupMapConfigProvider(mapConfig, cdbuser, self.userLimitsApi, rendererParams),
@@ -270,7 +262,6 @@ MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn
         function afterLayergroupCreate(err, layergroup) {
             assert.ifError(err);
 
-            res.locals.mapconfig = mapConfig;
             res.locals.analysesResults = mapConfigProvider.analysesResults;
             res.locals.layergroup = layergroup;
             res.locals.template = mapConfigProvider.template;
@@ -285,7 +276,6 @@ MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn
         },
         function finishTemplateInstantiation(err) {
             if (err) {
-                err.label = 'NAMED MAP LAYERGROUP';
                 return next(err);
             }
 
@@ -640,3 +630,38 @@ MapController.prototype.addWidgetsUrl = function(username, layergroup, mapConfig
         }.bind(this));
     }
 };
+
+function mapErrorMiddleware (options) {
+    const { augmentError = false, label = 'MAPS CONTROLLER' } = options;
+
+    return function mapError (err, req, res, next) {
+        const { mapconfig } = res.locals;
+
+        if (augmentError) {
+            err = Number.isFinite(err.layerIndex) ? populateError(err, mapconfig) : err;
+        }
+
+        err.label = label;
+
+        next(err);
+    };
+}
+
+function populateError(err, mapConfig) {
+    var error = new Error(err.message);
+    error.http_status = err.http_status;
+
+    if (!err.http_status && err.message.indexOf('column "the_geom_webmercator" does not exist') >= 0) {
+        error.http_status = 400;
+    }
+
+    error.type = 'layer';
+    error.subtype = err.message.indexOf('Postgis Plugin') >= 0 ? 'query' : undefined;
+    error.layer = {
+        id: mapConfig.getLayerId(err.layerIndex),
+        index: err.layerIndex,
+        type: mapConfig.layerType(err.layerIndex)
+    };
+
+    return error;
+}