browserNoActivityTimeout Configuration for Slow CI Environments

Browser Activity Monitoring

Karma uses the browserNoActivityTimeout setting to monitor the socket connection between the test runner and the captured browser. If the browser fails to signal activity within this window, Karma disconnects the browser and marks the run as failed to prevent silent stalls.

CI Performance Constraints

In heavily loaded CI environments or projects with large bundles, legitimate test execution or bundling phases may exceed the default 30-second timeout. While increasing this global value prevents false failures, a high threshold delays the detection of genuine deadlocks or browser crashes.

Because Karma applies this timeout globally across the entire suite, there is a tension between accommodating the slowest legitimate test and maintaining a responsive failure signal for true hangs.

• How can the browserNoActivityTimeout be tuned to balance CI stability against the need for rapid stall detection?
• Is there a documented method to apply different activity timeouts for specific test suites within a single configuration?