chore: fix flaky tests (net stubbing, websocket, proxy logging, Firefox system tests) (#19159)

system-tests/lib/system-tests.ts

@@ -273,14 +273,15 @@ export const STDOUT_DURATION_IN_TABLES_RE = /(\s+?)(\d+ms|\d+:\d+:?\d+)/g
 const diffRe = /Difference\n-{10}\n([\s\S]*)\n-{19}\nSaved snapshot text/m
 const expectedAddedVideoSnapshotLines = [
   'Warning: We failed processing this video.',
-  'This error will not alter the exit code.', '',
+  'This error will not alter the exit code.',
   'TimeoutError: operation timed out',
-  '[stack trace lines]', '', '',
+  '[stack trace lines]',
 ]
 const expectedDeletedVideoSnapshotLines = [
-  '(Video)', '',
+  '(Video)',
   '-  Started processing:  Compressing to 32 CRF',
 ]
+const sometimesAddedSpacingLine = ''
 const sometimesAddedVideoSnapshotLine = '│ Video:        false                                                                            │'
 const sometimesDeletedVideoSnapshotLine = '│ Video:        true                                                                             │'
 
@@ -303,8 +304,8 @@ const isVideoSnapshotError = (err: Error) => {
     if (line.charAt(0) === '-') deleted.push(line.slice(1).trim())
   }
 
-  _.pull(added, sometimesAddedVideoSnapshotLine)
-  _.pull(deleted, sometimesDeletedVideoSnapshotLine)
+  _.pull(added, sometimesAddedVideoSnapshotLine, sometimesAddedSpacingLine)
+  _.pull(deleted, sometimesDeletedVideoSnapshotLine, sometimesAddedSpacingLine)
 
   return _.isEqual(added, expectedAddedVideoSnapshotLines) && _.isEqual(deleted, expectedDeletedVideoSnapshotLines)
 }

system-tests/projects/e2e/cypress/integration/websockets_spec.js

@@ -24,7 +24,7 @@ describe('websockets', () => {
   it('does not crash', () => {
     cy.visit('http://localhost:3038/foo')
     cy.log('should not crash on ECONNRESET websocket upgrade')
-    cy.window().then((win) => {
+    cy.window().then({ timeout: 10000 }, (win) => {
       // see https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent
       return Cypress.Promise.all([
         shouldCloseUrlWithCode(win, 'ws://localhost:3038/websocket', 1006),