Changed null logic for range value mappings after PR comments

packages/grafana-ui/src/components/Gauge/Gauge.test.tsx

@@ -148,22 +148,9 @@ describe('Format value with value mappings', () => {
     expect(result.text).toEqual('<NULL>');
   });
 
-  it('should return if value is null and range to text mapping from is null', () => {
+  it('should return if value is null and range to text mapping from and to is null', () => {
     const valueMappings: ValueMapping[] = [
-      { id: 0, operator: '', text: '<NULL>', type: MappingType.RangeToText, from: 'null', to: '10' },
-      { id: 1, operator: '', text: 'elva', type: MappingType.ValueToText, value: '11' },
-    ];
-    const value = null;
-    const { instance } = setup({ valueMappings });
-
-    const result = instance.getFirstFormattedValueMapping(valueMappings, value);
-
-    expect(result.text).toEqual('<NULL>');
-  });
-
-  it('should return if value is null and range to text mapping to is null', () => {
-    const valueMappings: ValueMapping[] = [
-      { id: 0, operator: '', text: '<NULL>', type: MappingType.RangeToText, from: '1', to: 'null' },
+      { id: 0, operator: '', text: '<NULL>', type: MappingType.RangeToText, from: 'null', to: 'null' },
       { id: 1, operator: '', text: 'elva', type: MappingType.ValueToText, value: '11' },
     ];
     const value = null;

packages/grafana-ui/src/components/Gauge/Gauge.tsx

@@ -91,7 +91,8 @@ export class Gauge extends PureComponent<Props> {
       value === null &&
       rangeToTextMapping.from &&
       rangeToTextMapping.to &&
-      (rangeToTextMapping.from.toLowerCase() === 'null' || rangeToTextMapping.to.toLowerCase() === 'null')
+      rangeToTextMapping.from.toLowerCase() === 'null' &&
+      rangeToTextMapping.to.toLowerCase() === 'null'
     ) {
       return allValueMappings.concat(rangeToTextMapping);
     }