Heatmap: Improve error messaging if no numeric fields were provided (#113985)

* Heatmap: Improve error messaging if no numeric fields were provided

* update i18n

public/app/features/transformers/calculateHeatmap/heatmap.test.ts

@@ -108,4 +108,17 @@ describe('Heatmap transformer', () => {
       ]
     `);
   });
+
+  it('throws error if no numeric fields are present', async () => {
+    expect(() =>
+      rowsToCellsHeatmap({
+        frame: toDataFrame({
+          fields: [
+            { name: 'time', type: FieldType.time, values: [1, 2, 3, 4] },
+            { name: 'label', type: FieldType.string, values: ['a', 'b', 'c', 'd'] },
+          ],
+        }),
+      })
+    ).toThrowErrorMatchingInlineSnapshot(`"No numeric fields found for heatmap"`);
+  });
 });

public/app/features/transformers/calculateHeatmap/heatmap.ts

@@ -125,6 +125,10 @@ export function rowsToCellsHeatmap(opts: RowsHeatmapOptions): DataFrame {
   const xValues = xField.values;
   const yFields = opts.frame.fields.filter((f, idx) => f.type === FieldType.number && idx > 0);
 
+  if (yFields.length === 0) {
+    throw new Error(t('heatmap.error.no-y-fields', 'No numeric fields found for heatmap'));
+  }
+
   // similar to initBins() below
   const len = xValues.length * yFields.length;
   const xs = new Array(len);

public/app/plugins/panel/heatmap/HeatmapPanel.tsx

@@ -55,6 +55,7 @@ export const HeatmapPanel = (props: HeatmapPanelProps) => {
         timeRange,
       });
     } catch (ex) {
+      console.error(ex);
       return { warning: `${ex}` };
     }
   }, [data.series, data.annotations, options, palette, theme, replaceVariables, timeRange]);

public/locales/en-US/grafana.json

@@ -9153,6 +9153,9 @@
     "category-legend": "Legend",
     "category-tooltip": "Tooltip",
     "category-y-axis": "Y Axis",
+    "error": {
+      "no-y-fields": "No numeric fields found for heatmap"
+    },
     "mode-options": {
       "label-opacity": "Opacity",
       "label-scheme": "Scheme"