multiple-srcs: introduce calculatedProduction getter

Author: kaiosilveira

src/multiple-sources/index.js

@@ -9,6 +9,10 @@ export class ProductionPlan {
     return this._initialProduction + this._productionAccumulator;
   }
 
+  get calculatedProduction() {
+    return this._adjustments.reduce((sum, a) => sum + a.amount, 0);
+  }
+
   applyAdjustment(anAdjustment) {
     this._adjustments.push(anAdjustment);
     this._productionAccumulator += anAdjustment.amount;