René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Bundler-injected defaults override explicit `ClientEventBus` config","articleBody":"### TanStack Devtools version\n\n@tanstack/devtools-event-bus: 0.4.2 | @tanstack/devtools-vite: 0.8.3\n\n### Framework/Library version\n\n@tanstack/svelte-devtools: 0.1.3\n\n### Describe the bug and the steps to reproduce it\n\n`ClientEventBus` accepts explicit `port`, `host`, and `protocol` options, but a Vite or Rspack connection transform can override them. The constructor passes each explicit option through `getDefault*()` after destructuring [client.ts#L91-L105](https://github.com/TanStack/devtools/blob/53805408af7e6010e209f21a073204411bc1267f/packages/event-bus/src/client/client.ts#L91-L105).\n\nThe Vite connection-injection plugin replaces every `__TANSTACK_DEVTOOLS_*__` placeholder with the bundler's connection value [plugin.ts#L576-L608](https://github.com/TanStack/devtools/blob/53805408af7e6010e209f21a073204411bc1267f/packages/devtools-vite/src/plugin.ts#L576-L608). After that transform, each `getDefault*()` helper always returns the injected value, even when the caller supplied a different runtime value. For example, `new ClientEventBus({ host: 'devtools.example.com', port: 443, protocol: 'https' })` can still connect to the injected `localhost` HTTP endpoint.\n\nThis prevents applications behind a development proxy from directing the browser event bus through the public HTTPS origin. The client instead attempts to connect to the bundler's internal host, port, and protocol.\n\n### Expected behavior\n\nExplicit `ClientEventBus` options should take precedence over bundler-injected defaults. Bundler-injected values should apply when an option is omitted, and the built-in `localhost:4206` HTTP values should remain the final fallback.\n\nThe constructor can preserve that precedence by resolving each injected default in the parameter default and assigning an explicitly supplied value directly.\n\n### Your Minimal, Reproducible Example - (Sandbox Highly Recommended)\n\nhttps://stackblitz.com/edit/vitejs-vite-nz7smy9p?file=package.json,index.html,vite.config.ts,src%2Fmain.ts\n\n### Do you intend to try to help solve this bug with your own PR?\n\nYes, I am also opening a PR that solves the problem along side this issue\n\n### Terms & Code of Conduct\n\n- [x] I agree to follow this project's Code of Conduct\n- [x] I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.","author":{"url":"https://github.com/kolaworld","@type":"Person","name":"kolaworld"},"datePublished":"2026-08-15T22:13:53Z","url":"https://github.com/TanStack/devtools/issues/499"}