fix(http): merge default options when partial opts are provided

[oritwoen]

defineCachedHandler used a default parameter value instead of merging defaults into the function body. This meant passing partial options silently dropped all unspecified defaults.

defineCachedFunction already does this correctly (cache.ts line 28):

opts = { ...defaultCacheOptions(), ...opts };

But defineCachedHandler relied on the parameter default, which only applies when no argument is passed at all:

opts: CachedEventHandlerOptions<E> = defaultCacheOptions() // only when opts is undefined

The practical effect: defineCachedHandler(handler, { maxAge: 60 }) left swr as undefined, so the cache-control header logic fell into the non-SWR branch and produced max-age=60 instead of s-maxage=60, stale-while-revalidate. The cache layer itself worked fine (because cachedFunction merges defaults internally), but the HTTP-specific header logic read from the un-merged opts.

I noticed this while reading through the codebase - the inconsistency between how the two functions handle defaults stood out. PLAN.md already had it listed as issue #4.

The fix applies the same spread pattern from defineCachedFunction, plus a regression test that confirms SWR headers are produced when only maxAge is passed.

Summary by CodeRabbit

• Bug Fixes

  • Ensure default caching options are always merged with user-provided settings so partial configs produce correct cache behavior.

• Tests

  • Added tests confirming defaults are merged when partial caching options are supplied.

• Documentation

  • Updated the displayed API signature for the cached handler to reflect the new options behavior.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: e869878e-0993-417a-a11b-88f83405db8a

📥 Commits

Reviewing files that changed from the base of the PR and between 4888786 and 7e5e534.

📒 Files selected for processing (1)

• README.md

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📝 Walkthrough

Walkthrough

Refactored defineCachedHandler to apply default cache options by merging defaults with provided opts inside the function body; added tests verifying partial opts are merged; updated README snippet of the function signature.

Changes

Cohort / File(s)	Summary
Default Options Merging src/http.ts	Changed defineCachedHandler parameter default from defaultCacheOptions() as CachedEventHandlerOptions<E> to {} and now unconditionally merges defaults via opts = { ...defaultCacheOptions(), ...opts } at function start.
Test Coverage test/index.test.ts	Added two tests ensuring partial options (e.g., maxAge) are merged with defaults and produce expected cache-control headers.
Docs Snippet README.md	Updated the documented TypeScript snippet for defineCachedHandler, removing the explicit default initializer and the trailing return-type/closure in the snippet.

Sequence Diagram(s)

(omitted)

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• fix(http): merge default options when partial opts are provided #2 — Makes the same change in src/http.ts to merge default cache options with provided opts using object spread.

Poem

🐰 I hopped through code with gentle flair,
I spread the defaults everywhere,
No casts, just merges — tidy, neat,
Tests applaud my little feat,
A caching carrot, safe to share.

🚥 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 title clearly and specifically describes the main change: fixing how default options are merged when partial options are provided to defineCachedHandler.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

📝 Coding Plan

• Generate coding plan for human review comments

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[pi0]

thnx!