Reduce complexity by extracting a complex condition to a function

lib/cartodb/backends/cluster.js

@@ -7,7 +7,7 @@ const AggregationMapConfig = require('../models/aggregation/aggregation-mapconfi
 
 module.exports = class ClusterBackend {
     // TODO: reduce complexity
-    // jshint maxcomplexity: 17
+    // jshint maxcomplexity: 16
     getClusterFeatures (mapConfigProvider, params, callback) {
         mapConfigProvider.getMapConfig((err, _mapConfig) => {
             if (err) {
@@ -26,7 +26,7 @@ module.exports = class ClusterBackend {
 
             const layer = mapConfig.getLayer(layerIndex);
 
-            if (layer.options.aggregation === false || !mapConfig.isAggregationLayer(layerIndex)) {
+            if (!hasAggregationLayer(mapConfig, layerIndex)) {
                 const error = new Error(`Map ${token} has no aggregation defined for layer ${layerIndex}`);
                 error.http_status = 400;
                 error.type = 'layer';
@@ -37,6 +37,7 @@ module.exports = class ClusterBackend {
                 };
 
                 debug(error);
+
                 return callback(error);
             }
 
@@ -249,3 +250,14 @@ const aggregationQuery = ctx => `
     FROM (${ctx.query}) __cdb_aggregation
     ${ctx.columns.length ? `GROUP BY ${ctx.columns.join(', ')}` : ''}
 `;
+
+// TODO: update when https://github.com/CartoDB/Windshaft-cartodb/pull/1082 is merged
+function hasAggregationLayer (mapConfig, layerIndex) {
+    const layer = mapConfig.getLayer(layerIndex);
+
+    if (typeof layer.options.aggregation === 'boolean') {
+        return layer.options.aggregation;
+    }
+
+    return mapConfig.isAggregationLayer(layerIndex);
+}