Enhance middleware documentation with error handling details

[Bryson14]

Added explanation for error handling in middleware and provided an example of authentication middleware. I had to find this information from this discussion and not from the middleware documentation page:

#2887

Added:

• example of using middlware for auth, throwing 500 errors, throwing 4XX errors, and passing context along
• more explicit details about what middlware can do

Summary by CodeRabbit

• Documentation
  • Expanded middleware docs with practical TypeScript examples showing how middleware can short‑circuit by throwing errors or returning controlled JSON responses (e.g., 401) and how to pass context to downstream middleware/server functions. Clarifies default error behavior, contrasts throwing vs. controlled responses, and augments the middleware request-flow guidance to improve real-world error-handling patterns.

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[coderabbitai]

📝 Walkthrough

Walkthrough

Added documentation explaining middleware error behavior: thrown errors default to a 500 with Error data; shows using json(...) to return a custom HTTP status (e.g., 401) and demonstrates passing context to downstream handlers via next().

Changes

Cohort / File(s)	Summary
Middleware Error Handling Documentation docs/start/framework/react/guide/middleware.md	Inserted a block clarifying that thrown errors produce a 500 by default, showed how to use json(...) to customize status codes (example: 401), and added a TSX example demonstrating throwing vs returning json(...) and returning context to next()

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Poem

🐰 I hop through docs where code and thoughts align,
Errors now speak with a clearer sign.
Throw or send json — the path is bright,
Context carried onward in morning light.
🥕✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title directly and clearly describes the main change: enhancing middleware documentation with error handling details, which matches the actual addition of a documentation block explaining error handling in middleware.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@docs/start/framework/react/guide/middleware.md`:
- Line 82: Fix the typo "middlware" to "middleware" in the paragraph that reads
"If you want to return another error code, like with an authentication
middlware, you can throw the `json` helper." Locate the sentence in
docs/start/framework/react/guide/middleware.md (the line referencing throwing
the `json` helper) and correct the spelling to "authentication middleware".
- Around line 87-100: The TSX example has mismatched braces and a missing
closing parenthesis/semicolon causing unreachable code; update the
authMiddleware created by createMiddleware().server so the async callback
properly closes its if blocks and the server call: ensure the null-check for
client and the user-not-found json response both close their braces, then place
the return await next({ context: { user } }) inside the async function before
closing the server(...) call and terminate with the final `);` so the
authMiddleware, createMiddleware().server, and the async function scopes
(references: authMiddleware, createMiddleware().server, getMyDb, next, request)
are balanced and reachable.