Avoid NaN percentage passed when nothing ran (#363)

Author: davidjgoss

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 ### Fixed
+- Avoid NaN percentage passed when nothing ran ([#363](https://github.com/cucumber/react-components/pull/363))
 - Don't render hook steps with no content ([#361](https://github.com/cucumber/react-components/pull/361))
 
 ## [22.3.0] - 2024-08-02

src/components/app/ExecutionSummary.spec.tsx

@@ -102,6 +102,7 @@ describe('ExecutionSummary', () => {
       [5, 45, '11%'],
       [45, 45, '100%'],
       [0, 45, '0%'],
+      [0, 0, '0%'],
     ]
 
     for (const [passed, total, percentage] of examples) {

src/components/app/ExecutionSummary.stories.tsx

@@ -83,3 +83,14 @@ WithCi.args = {
   testRunFinished,
   meta: metaWithCi,
 } as IExecutionSummaryProps
+
+export const NoTestCases = Template.bind({})
+NoTestCases.args = {
+  scenarioCountByStatus: {
+    ...makeEmptyScenarioCountsByStatus(),
+  },
+  totalScenarioCount: 0,
+  testRunStarted,
+  testRunFinished,
+  meta: metaMinimal,
+}

src/components/app/ExecutionSummary.tsx

@@ -48,7 +48,11 @@ export const ExecutionSummary: React.FunctionComponent<IExecutionSummaryProps> =
   const percentagePassed: string =
     new Intl.NumberFormat(undefined, {
       style: 'percent',
-    }).format(scenarioCountByStatus[TestStepResultStatus.PASSED] / totalScenarioCount) + ' passed'
+    }).format(
+      totalScenarioCount > 0
+        ? scenarioCountByStatus[TestStepResultStatus.PASSED] / totalScenarioCount
+        : 0
+    ) + ' passed'
   const startDate = testRunStarted?.timestamp
     ? new Date(TimeConversion.timestampToMillisecondsSinceEpoch(testRunStarted.timestamp))
     : undefined