From 89b2e110837ae3d61478d8bf06ae538116f74332 Mon Sep 17 00:00:00 2001
From: nymkappa <vialjoris@hotmail.com>
Date: Tue, 12 Jul 2022 09:03:39 +0200
Subject: [PATCH] [Hashrate chart] Fix javascript error if difficulty array is
 empty

---
 .../hashrate-chart/hashrate-chart.component.ts     | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/frontend/src/app/components/hashrate-chart/hashrate-chart.component.ts b/frontend/src/app/components/hashrate-chart/hashrate-chart.component.ts
index 385be0669..2a7cc07f2 100644
--- a/frontend/src/app/components/hashrate-chart/hashrate-chart.component.ts
+++ b/frontend/src/app/components/hashrate-chart/hashrate-chart.component.ts
@@ -109,7 +109,7 @@ export class HashrateChartComponent implements OnInit {
                     while (hashIndex < data.hashrates.length) {
                       diffFixed.push({
                         timestamp: data.hashrates[hashIndex].timestamp,
-                        difficulty: data.difficulty[data.difficulty.length - 1].difficulty
+                        difficulty: data.difficulty.length > 0 ?  data.difficulty[data.difficulty.length - 1].difficulty : null
                       });
                       ++hashIndex;
                     }
@@ -231,11 +231,15 @@ export class HashrateChartComponent implements OnInit {
             } else if (tick.seriesIndex === 1) { // Difficulty
               let difficultyPowerOfTen = hashratePowerOfTen;
               let difficulty = tick.data[1];
-              if (this.isMobile()) {
-                difficultyPowerOfTen = selectPowerOfTen(tick.data[1]);
-                difficulty = Math.round(tick.data[1] / difficultyPowerOfTen.divider);
+              if (difficulty === null) {
+                difficultyString = `${tick.marker} ${tick.seriesName}: No data<br>`;  
+              } else {
+                if (this.isMobile()) {
+                  difficultyPowerOfTen = selectPowerOfTen(tick.data[1]);
+                  difficulty = Math.round(tick.data[1] / difficultyPowerOfTen.divider);
+                }
+                difficultyString = `${tick.marker} ${tick.seriesName}: ${formatNumber(difficulty, this.locale, '1.2-2')} ${difficultyPowerOfTen.unit}<br>`;
               }
-              difficultyString = `${tick.marker} ${tick.seriesName}: ${formatNumber(difficulty, this.locale, '1.2-2')} ${difficultyPowerOfTen.unit}<br>`;
             } else if (tick.seriesIndex === 2) { // Hashrate MA
               let hashrate = tick.data[1];
               if (this.isMobile()) {