test: updating path separator for mochaEvents (#28265)

.circleci/workflows.yml

@@ -85,6 +85,7 @@ windowsWorkflowFilters: &windows-workflow-filters
     - equal: [ 'chore/update_webpack_deps_to_latest_webpack4_compat', << pipeline.git.branch >> ]
     - equal: [ 'lerna-optimize-tasks', << pipeline.git.branch >> ]
     - equal: [ 'em/shallow-checkout', << pipeline.git.branch >> ]
+    - equal: [ 'mschile/mochaEvents_win_sep', << pipeline.git.branch >> ]
     - matches:
         pattern: /^release\/\d+\.\d+\.\d+$/
         value: << pipeline.git.branch >>

packages/app/cypress/e2e/runner/support/mochaEventsUtils.ts

@@ -204,5 +204,8 @@ function sanitizeMochaEvents (args: CypressInCypressMochaEvent[]) {
 }
 
 function getCallerFilename () {
-  return (new Error()).stack!.split('\n')[1].split('/').slice(-1)[0].split(':')[0]
+  const line = (new Error()).stack!.split('\n')[1]
+  const pathSep = line.includes('\\') ? '\\' : '/'
+
+  return line.split(pathSep).slice(-1)[0].split(':')[0]
 }