fix(testrunner): attribute unhandle promise reject to a single worker (#1491)
fix(testrunner): attribute unhandle promise reject to a single worker (#1491)

When there is a single worker, we are almost sure the error originated in that worker. Attributing it helps with context by showing last run tests.
microsoft/playwright,microsoft/playwright,microsoft/playwright,microsoft/playwright,microsoft/playwright,microsoft/playwright,microsoft/playwright,microsoft/playwright,microsoft/playwright