fix: handle empty checks in tech-insights scorecard

Show a warning about missing data instead of crashing if checks return empty.

Signed-off-by: Jacob Wejendorp <jwe@tradeshift.com>

plugins/tech-insights/src/components/ScorecardsOverview/ChecksOverview.tsx

@@ -21,6 +21,7 @@ import { Content, Page, InfoCard } from '@backstage/core-components';
 import { CheckResult } from '@backstage/plugin-tech-insights-common';
 import { techInsightsApiRef } from '../../api/TechInsightsApi';
 import { BackstageTheme } from '@backstage/theme';
+import { Alert } from '@material-ui/lab';
 
 const useStyles = makeStyles((theme: BackstageTheme) => ({
   contentScorecards: {
@@ -40,6 +41,9 @@ type Checks = {
 export const ChecksOverview = ({ checks }: Checks) => {
   const classes = useStyles();
   const api = useApi(techInsightsApiRef);
+  if (!checks.length) {
+    return <Alert severity="warning">No checks have any data yet.</Alert>;
+  }
   const checkRenderType = api.getScorecardsDefinition(
     checks[0].check.type,
     checks,