Merge pull request #2473 from cfpb/2472-only-save-failing-test-runs

## Changes

- delete videos that don't contain a test failure, as [per the docs](https://docs.cypress.io/app/guides/screenshots-and-videos#Delete-videos-for-specs-without-failing-or-retried-tests)

## Testing

1. Does the test suite run normally?
2. Do tests that pass not have saved videos?
![Screenshot 2025-04-07 at 6 05 00 PM](https://github.com/user-attachments/assets/de1f5eb2-8b07-497f-9701-96a36a97e9bf)
3. Do tests that fail still have saved videos?
![Screenshot 2025-04-07 at 6 07 28 PM](https://github.com/user-attachments/assets/25973d4c-0f31-45fd-98f5-6d9f0028c322)

Closes: #2472

Author: billhimmelsbach

cypress.config.js

@@ -1,4 +1,5 @@
 const { defineConfig } = require('cypress')
+const fs = require('fs')
 
 module.exports = defineConfig({
   chromeWebSecurity: false,
@@ -41,6 +42,24 @@ module.exports = defineConfig({
       runMode: 2,
       openMode: 0
     },
+    // Delete videos for specs without failing or retried tests, see docs:
+    // https://docs.cypress.io/app/guides/screenshots-and-videos#Delete-videos-for-specs-without-failing-or-retried-tests
+    setupNodeEvents(on, config) {
+      on('after:spec', (spec, results) => {
+        if (results && results.video) {
+          // Do we have failures for any retry attempts?
+          const failures = results.tests.some((test) =>
+            test.attempts.some((attempt) => attempt.state === 'failed')
+          )
+          // Check to make sure the video file exists before deleting, see https://stackoverflow.com/a/76113045
+          if (!failures && fs.existsSync(results.video)) {
+            // delete the video if the spec passed and no tests retried
+            fs.unlinkSync(results.video)
+            console.log(`All tests passed, deleting video file: ${results.video}`)
+          }
+        }
+      })
+    },
   },
 
   component: {