writing-dev-server-tests

To write tests for Bun dev-server hot module replacement, use bake-harness utilities like devTest and Client to validate live reloads and bundle updates. This approach structures tests to exercise HMR behavior across HTML, CSS, and JS file changes.

A dev-server test harness is a structured testing setup that exercises live reloading and module replacement during development. You need one to ensure reliable hot-reload behavior and reduce manual debugging when updating HTML, CSS, or JS files.

To test that CSS and HTML changes trigger correct reloads in a Bun development environment, structure tests using bake-harness utilities to validate bundle updates and file modifications. This verifies that dev-server behavior responds accurately to frontend changes.

Yes, the bake-harness test structure enforces a consistent test setup for both development and production modes. This allows you to validate bundle behavior and dev-server functionality across different environment configurations.

The best way to organize frontend tests for ES modules and React refresh in Bun is to categorize test suites by scenario. Structure tests to cover bundle, CSS, HTML, React refresh, and ES module updates using a consistent harness.

HMR tests often fail to validate bundle updates when not using a structured test harness. Implementing bake-harness utilities like devTest and Client ensures that dev-server behavior and hot-reloading are properly exercised and validated.