qa-cache-testing
Cache testing across layers: Redis cache patterns, CDN cache-purge testing (Cloudflare, Fastly, CloudFront), Varnish VTC syntax, browser Cache-Control tests, cache-coherence + stampede + stale-while-revalidate references, and a cache-key collision detector. Covers RFC 9111 HTTP caching and the canonical multi-tier cache discipline (browser to CDN to app to data store).
Install this plugin
/plugin install qa-cache-testing@testland-qaPart of role bundle: qa-role-backend
qa-cache-testing
Cache testing across layers: Redis cache patterns, CDN cache-purge testing (Cloudflare, Fastly, CloudFront) with browser-tier Cache-Control tests in its references, Varnish VTC syntax, a cache-coherence reference (with stampede and stale-while-revalidate deep references), a cache-key discriminator audit, and a cache-key collision detector. Covers RFC 9111 HTTP caching and the canonical multi-tier cache discipline (browser to CDN to app to data store).
Components
| Type | Name | Description |
|---|---|---|
| Skill | cache-coherence-patterns-reference | Pure-reference catalog of cache-coherence patterns across the request path; stampede + stale-while-revalidate deep references in references/. |
| Skill | cdn-cache-purge-tests | Wraps CDN cache-purge testing patterns for Cloudflare / Fastly / CloudFront; client-tier browser Cache-Control tests in references/. |
| Skill | redis-cache-tests | Wraps Redis cache testing patterns: EXPIRE / PEXPIRE / TTL command verification (with the Redis 7+ NX/XX/GT/LT flags), the cache-aside wr... |
| Skill | varnish-test-vtc-syntax | Wraps the varnishtest CLI + VTC (Varnish Test Case) syntax for testing VCL configurations. |
| Skill | cache-key-discriminator-audit | Audits whether a cache key carries every discriminator the response depends on, ranking identity discriminators above presentation ones because a missing tenant is a data leak, not a performance bug. |
| Agent | cache-key-collision-detector | Read-only specialist that scans application code for cache-key collision risks - keys that should be unique per (tenant, user, locale, re... |
Install
/plugin marketplace add testland/qa
/plugin install qa-cache-testing@testland-qaSkills
cache-coherence-patterns-reference
Pure-reference catalog of cache-coherence patterns across the request path. Defines the five-tier cache stack (browser → CDN → reverse-proxy → application → data store), the per-tier cache-writing patterns (cache-aside, write-through, write-back, write-around, refresh-ahead), and the canonical invalidation strategies (TTL-only, event-driven purge, surrogate keys, version-tagged URLs, soft purge), plus an anti-pattern table and a worked multi-tenant coherence-test example. Deep detail lives in references/: RFC 9111 Cache-Control / Vary / ETag directive tables, the cross-tier test surface, cache-stampede (thundering-herd) mitigations incl. the XFetch formula, and RFC 5861 stale-while-revalidate / stale-if-error semantics. Use for pattern selection, Cache-Control header design, coherence audits, stampede-refresh strategy, and SWR/SIE window design; use a cache-key-collision check when the question is whether two concrete requests collide on a key scheme.
cache-key-discriminator-audit
Audits whether a cache key carries every discriminator the cached response actually depends on, so two requests that must not share a slot cannot collide. Ranks identity discriminators (tenant, user, authorization scope, plan tier) above presentation ones (locale, region, currency, feature flag), maps each missing discriminator to the data-exposure or wrong-content consequence it causes, classifies each key-and-value pair into a critical / high / medium severity band (including the Python lru_cache-on-an-instance-method trap), and writes the fix as a namespaced key builder plus the matching HTTP Vary header. Use when a cache key is being designed or changed, when a per-user or per-tenant response is about to be stored in a shared cache or CDN, or when investigating a report that one user or tenant saw another's data.
cdn-cache-purge-tests
Wraps CDN cache-purge testing patterns for Cloudflare (POST /zones/{zone_id}/purge_cache, single-file / everything / cache-tags / hostname / prefix), Fastly (POST purge-by-key / purge-all, surrogate-keys via Surrogate-Key header), and CloudFront (CreateInvalidation API + paths). Covers end-to-end test patterns (write origin → trigger purge → assert edge serves fresh), purge-propagation delay testing (typically 1-30s globally), surrogate-key + cache-tag patterns for group-purge, and Cache-Status header verification (cf-cache-status: HIT/MISS/BYPASS). Also owns the client tier: browser-side Cache-Control verification with Playwright (served-from-cache via CDP, ETag 304 round-trips, Workbox service-worker strategies, reload semantics) in references/browser-cache-control.md. Use when designing or auditing CDN cache-invalidation workflows or browser-tier caching behaviour in E2E tests.
redis-cache-tests
Wraps Redis cache testing: EXPIRE / PEXPIRE / TTL verification (Redis 7+ NX/XX/GT/LT flags), cache-aside write-then-invalidate (write source → DEL key → assert fresh read), eviction under memory pressure (maxmemory + allkeys-lru), pub/sub invalidation across nodes, and tenant key-namespacing. Use when Redis is the app's primary cache. For the CDN/browser HTTP tier use cdn-cache-purge-tests; a runnable test, not the cache-coherence-patterns-reference catalog (which owns the stampede + stale-while-revalidate references).
varnish-test-vtc-syntax
Wraps the varnishtest CLI + VTC (Varnish Test Case) syntax for testing VCL configurations. Covers the VTC test-file format (varnishtest scripts with server { ... } + client { ... } + varnish v1 -vcl+backend { ... } blocks), the grace-mode + saint-mode behaviours (stale-while-revalidate + stale-if-error equivalents in VCL), the PURGE method handler pattern (vcl_purge subroutine + ACL guards), and surrogate-key invalidation via xkey vmod. Use when authoring or testing Varnish-based caching layers.