fix(api): add response caching to /insurance/:slab [BUG-106]

[Morenikeoa]

Problem

GET /insurance/:slab is wrapped by neither cacheMiddleware nor withDbCacheFallback — every single request, concurrent or not, runs two sequential un-batched Supabase queries (market_stats then insurance_history) with zero protection. Its sibling /open-interest/:slab (same query shape, same data source) already has cacheMiddleware(15).

Impact

A burst of concurrent clients hitting this endpoint (e.g. a dashboard polling insurance data for multiple markets) directly multiplies into 2N concurrent Postgres queries with no caching layer to absorb repeat/concurrent traffic, unlike every comparable route.

Fix

Applied the identical cacheMiddleware(15) already used by /open-interest/:slab.

Test fix needed alongside this

The existing test file didn't call clearCache() between tests. Several tests reuse the same slab address across different mock setups (expecting different DB responses each time) — once caching was added, the second+ test using the same path started getting the first test's cached response instead of hitting its own mock, breaking 4 unrelated tests. Added clearCache() to beforeEach, matching the convention already used in open-interest.test.ts.

Proof of Fix

New test: two requests for the same slab — the second is served from cache (X-Cache: HIT header) with no additional Supabase calls.

Verified this is a genuine regression test: reverted just the source change and reran — failed because X-Cache was never set (no caching existed). Restored the fix and it passes.

• All existing tests pass — output attached.
• New regression test passes against the fix, fails against pre-fix code (verified locally).
• tsc --noEmit clean (no separate lint script in this repo).

Test Output

✓ tests/routes/insurance.test.ts (11 tests) 64ms

Full suite: 295/296 passed (294 baseline + 1 new). The 1 failure (tests/sdk-smoke.test.ts) is pre-existing and unrelated — it asserts on an exact @percolatorct/sdk error-message string that has drifted from the locally-resolved SDK version in this environment.

Related

Found during a broader API audit; no existing open issue/PR covers this.

Summary by CodeRabbit

• New Features
  • Added response caching for insurance slab requests, helping repeated lookups return faster.
• Tests
  • Added coverage to verify cached responses are served on repeat requests.
  • Updated test setup to clear cached data between cases for reliable results.

[vercel]

@Princessdada is attempting to deploy a commit to the Khubair Nasir's projects Team on Vercel.

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[coderabbitai]

📝 Walkthrough

Walkthrough

GET /insurance/:slab now uses cache middleware, and the insurance route tests reset cache state before each test and verify repeated requests return a cache hit without another Supabase query.

Changes

Insurance route caching

Layer / File(s)	Summary
Route caching middleware src/routes/insurance.ts	GET /insurance/:slab now imports cacheMiddleware and applies cacheMiddleware(15) before validateSlab.
Cache test coverage tests/routes/insurance.test.ts	The test suite imports clearCache, resets cached responses in beforeEach, and adds a cache-hit test that checks X-Cache: HIT and no extra Supabase from(...) call.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

A bunny hopped by, ears up high,
“Cache the slab and let it fly!”
One hop says “miss,” the next says “hit,”
No extra fetches—just a fit. 🐇

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main change: adding response caching to the insurance slab route.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/routes/insurance.ts`:
- Line 35: The current cacheMiddleware(15) usage on app.get("/insurance/:slab")
only caches completed responses and still allows concurrent requests to trigger
duplicate Supabase work on a cold miss. Update the cache layer itself, not just
the route, to add in-flight request coalescing for the same cache key so the
first request runs the handler and others await its result before hitting the
two Supabase queries. Use the cacheMiddleware contract and its underlying
storage/next flow to locate the fix, ensuring concurrent burst protection is
handled centrally.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a5fcd924-02ff-487f-ab48-40b995cd771a

📥 Commits

Reviewing files that changed from the base of the PR and between b2751f4 and 63b35ba.

📒 Files selected for processing (2)

• src/routes/insurance.ts
• tests/routes/insurance.test.ts

[coderabbitai]

🚀 Performance & Scalability | 🟠 Major | 🏗️ Heavy lift

cacheMiddleware(15) does not prevent concurrent cold-miss stampedes.

At Line 35, this only helps once a response is already cached. The current cache contract checks storage before next() and writes after the handler finishes, so two same-key requests arriving together will still both run the two Supabase queries. If concurrent burst protection is part of this fix, it needs in-flight request coalescing in the cache layer, not just TTL caching.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/routes/insurance.ts` at line 35, The current cacheMiddleware(15) usage on
app.get("/insurance/:slab") only caches completed responses and still allows
concurrent requests to trigger duplicate Supabase work on a cold miss. Update
the cache layer itself, not just the route, to add in-flight request coalescing
for the same cache key so the first request runs the handler and others await
its result before hitting the two Supabase queries. Use the cacheMiddleware
contract and its underlying storage/next flow to locate the fix, ensuring
concurrent burst protection is handled centrally.