single-src: assert production has the same value as calculatedProduction

Author: kaiosilveira

src/single-source/index.js

@@ -1,10 +1,13 @@
+import assert from 'node:assert';
+
 export class ProductionPlan {
   constructor() {
     this._adjustments = [];
     this._production = 0;
   }
 
   get production() {
+    assert(this._production === this.calculatedProduction);
     return this._production;
   }