René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Feature]: Guaranteed hydration correctness — graduate mismatch handling past dev-only warnings","articleBody":"**Pre-flight checklist**\n- [x] I searched existing issues and did not find a duplicate request.\n- [x] I explained the problem or use case, not just the desired API.\n\n**Problem or use case**\nHydration-mismatch detection currently lives in `verifyHydration` as **dev-only warnings**. In production a mismatch silently yields a wrong or broken UI with no recovery path, which is exactly the failure mode teams need guarantees against before trusting SSR. \"Dev-only warnings\" is not a stability contract, so this blocks `ssr` Stable (#127).\n\n**Proposed solution**\nAdd a production hydration-mismatch strategy: detect mismatches at hydrate time and offer configurable recovery — `warn` (dev default), `repair` (re-render the affected boundary from client state), or `error` (surface to an error boundary). Provide a stable, documented definition of what constitutes a mismatch and ensure detection covers the directives made SSR-capable in #128. Keep the production path lightweight (boundary-scoped, not whole-document).\n\n**Possible API or UX shape**\n```ts\nimport { hydrate } from \"@bquery/bquery/ssr\";\n\nhydrate(root, {\n  onMismatch: \"repair\",          // \"warn\" | \"repair\" | \"error\"\n  onError: (err, boundary) =\u003e reportToDevtools(err, boundary)\n});\n```\n\n**Alternatives considered**\nRelying on authors to keep server and client output identical by discipline — fragile, and undermined today by the directive subset in #128. Whole-document re-render on any mismatch — rejected as a performance cliff; boundary-scoped repair is the React/Svelte-aligned approach.\n\n**Relevant area**\n`ssr`\n\n**Additional context**\nReact 19 and Svelte both treat hydration mismatches as first-class with defined recovery; matching that is table stakes for production SSR. Wire the `onError` hook into the devtools bridge (#146) so mismatches are inspectable.\n","author":{"url":"https://github.com/JosunLP","@type":"Person","name":"JosunLP"},"datePublished":"2026-06-26T21:25:03.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/130/bQuery/issues/130"}