Fix possible division by zero in calculateAverage function

src/handlers/metricTypes/stats.ts

@@ -1,5 +1,5 @@
 import { MetricSchema, Stats } from "../../types";
-import { calcMedian } from "../../utils";
+import { calcMedian, calculateAverage } from "../../utils";
 
 export class GraphiteStats implements Stats {
   private count = 0;
@@ -11,13 +11,9 @@ export class GraphiteStats implements Stats {
     public readonly tags?: Record<string, string>
   ) {}
 
-  private calculateAverage(values: number[]): number {
-    return values.reduce((a, b) => a + b, 0) / values.length;
-  }
-
   get(): MetricSchema[] {
     const median = calcMedian(this.values);
-    const avg = this.calculateAverage(this.values);
+    const avg = calculateAverage(this.values);
 
     const time = Date.now();
 

src/utils.ts

@@ -8,3 +8,9 @@ export const calcMedian = (arr: number[]): number | undefined => {
   const mid = Math.floor(s.length / 2);
   return s.length % 2 === 0 ? (s[mid - 1] + s[mid]) / 2 : s[mid];
 };
+
+export const calculateAverage = (arr: number[]): number => {
+  return arr.length
+    ? arr.reduce((a, b) => a + b, 0) / arr.length
+    : 0;
+};