fix: skip 304 short-circuit when get bypasses cache

[cursor]

Bug and impact

Returning null or undefined from .get() is a documented cache bypass. After #138 fixed the null crash, a follow-up request with a matching If-None-Match header (browser refresh, CDN, API client) still returned 304 with an empty body instead of calling send(). Bypass routes silently lost their response body.

Root cause

When .get() bypasses the cache, memoize returns raw = undefined. The handler falls back to {} for etag computation, producing a deterministic ETag. The 304 branch only checked !forceExpiration && !isModified, so a matching If-None-Match skipped send() even though nothing was cached.

Fix

Only return 304 when memoize produced a stored value (raw is truthy). Cache revalidation after a cleared cache still works because get() re-fetches and returns a truthy raw.

Validation

• Added regression test: MISS for null data value with If-None-Match
• Full suite: 28/28 tests pass
• Manual repro confirmed: bypass + If-None-Match now returns 200 with body instead of empty 304

  

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Note

Low Risk
Single guard on the 304 branch in the HTTP cache handler; behavior change is limited to documented cache-bypass paths and is covered by a new test.

Overview
Fixes empty 304 responses on cache-bypass routes when clients send If-None-Match.

When .get() returns null/undefined (documented bypass), memoize does not store a payload, but the handler could still treat a matching ETag as “not modified” and return 304 without calling send(), so refreshes/CDN revalidation got an empty body.

The 304 path now requires hasValue (a real memoized entry) in addition to !forceExpiration and a matching ETag, so bypass requests always fall through to send() with 200 and the body. Normal cached revalidation is unchanged when get() returns a stored object.

Adds regression coverage in test/status.js for null .get() plus If-None-Match.

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