fix: error on getDataSetByLabel

Author: farfromrefug

src/charting/data/ChartData.ts

@@ -3,6 +3,7 @@ import { AxisDependency } from '../components/YAxis';
 import { IValueFormatter } from '../formatter/IValueFormatter';
 import { Highlight } from '../highlight/Highlight';
 import { IDataSet } from '../interfaces/datasets/IDataSet';
+import { DataSet } from './DataSet';
 
 export abstract class ChartData<U extends Entry, T extends IDataSet<U>> {
     /**
@@ -271,11 +272,12 @@ export abstract class ChartData<U extends Entry, T extends IDataSet<U>> {
      * @param ignorecase if true, the search is not case-sensitive
      * @return
      */
-    protected getDataSetIndexByLabel(dataSets, label, ignorecase) {
+    protected getDataSetIndexByLabel(dataSets: T[], label: string, ignorecase) {
         if (ignorecase) {
-            for (let i = 0; i < dataSets.length; i++) if (label.equalsIgnoreCase(dataSets[i].getLabel())) return i;
+            const toTest = label.toLowerCase();
+            for (let i = 0; i < dataSets.length; i++) if (toTest === dataSets[i].getLabel()?.toLowerCase()) return i;
         } else {
-            for (let i = 0; i < dataSets.length; i++) if (label.equals(dataSets[i].getLabel())) return i;
+            for (let i = 0; i < dataSets.length; i++) if (label === dataSets[i].getLabel()) return i;
         }
 
         return -1;

src/charting/data/PieData.ts

@@ -45,8 +45,8 @@ export class PieData extends ChartData<PieEntry, PieDataSet> {
         return index === 0 ? this.getDataSet() : null;
     }
 
-    public getDataSetByLabel(label, ignoreCase): PieDataSet {
-        return ignoreCase ? (label.equalsIgnoreCase(this.mDataSets[0].getLabel()) ? this.mDataSets[0] : null) : label.equals(this.mDataSets[0].getLabel()) ? this.mDataSets[0] : null;
+    public getDataSetByLabel(label: string, ignoreCase): PieDataSet {
+        return ignoreCase ? (label?.toLowerCase() === this.mDataSets[0].getLabel()?.toLowerCase() ? this.mDataSets[0] : null) : label === this.mDataSets[0].getLabel() ? this.mDataSets[0] : null;
     }
 
     public getEntryForHighlight(highlight: Highlight): Entry {