Which Karma configuration strategy minimizes file-loading overhead for large test suites?

Karma serves as a transport layer that launches real browsers and pipes results back to a Node.js process. In large-scale JavaScript projects, the files array in karma.conf.js can become a performance bottleneck during the initial browser load phase.

When managing hundreds of test files, there is a trade-off between loading individual files to maintain granular tracking and using a single bundled file to reduce HTTP requests and browser parsing overhead. This is particularly relevant when integrating with bundlers like Webpack or Rollup.

Does Karma provide a native mechanism to optimize the delivery of these assets to the browser without relying entirely on external bundling tools? What is the impact on test execution speed when switching from a glob-pattern file list to a single bundled entry point?