modbus-webserial / for-devs

The project has a fairly extensive automated test suite using vitest. However, browser testing is still required because the runtime environment is fundamentally different. In particular, the library interacts with browser APIs such as WebSerial, which cannot be fully simulated in the Node test environment.

For this reason, a set of simple browser examples is provided in the examples/ directory. These can be used to test the library directly against real hardware in a real browser environment.

How examples load the library

All example pages load modbus-webserial dynamically via an import map that can be overridden through a query parameter.

Because of this mechanism, the library source can be changed simply by adding a query parameter:

?src=<url>

Example:

http://localhost:3000/simple-test/?src=https://unpkg.com/modbus-webserial@latest/dist/index.js

Testing local builds

For development, a small test server is included which serves the example pages and the locally built library.

node scripts/dev-server.mjs 3000

This will:

• Serve examples/ at http://localhost:3000
• Expose the build output at http://localhost:3000/dist
• Automatically reload the browser when files change

Loading the local build

The server supports a convenience parameter ?local which redirects the page to load the locally built library.

Example:

http://localhost:3000/simple-test/?local

which resolves to:

http://localhost:3000/simple-test/?src=http://localhost:3000/dist/index.js

This allows testing local changes against the example pages without modifying any example files.