summercms/.planning/phases/06-http-routing-auth-groups-and-rate-limiting/06-09-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
06-http-routing-auth-groups-and-rate-limiting	09	http	surf panic-recovery response-buffering raw-routes security	phase provides 06-http-routing-auth-groups-and-rate-limiting raw/house route separation, bare and opaque panic recovery contracts, and wire.WriteOpaque500	Transactional response buffering shared by house and raw panic recovery Partial-status, header, and body disclosure regressions for both route kinds Successful explicit-status and implicit-200 buffered response coverage	phase-08-oauth phase-12-api-routes phase-14-api-routes	added patterns Route output is buffered privately and committed only after successful handler return Panic recovery discards route-owned status, headers, and body before writing the contract fallback	created modified surf/router.go surf/router_test.go	Use one unexported bufferedResponse for house and raw recovery so panic-before-write and panic-after-write have identical fallback behavior Implement http.Flusher as a no-op without exposing the destination writer, preserving the discard-on-panic guarantee Replace only buffered header keys during success commit so outer response headers such as path-scoped CORS remain intact	Transactional HTTP recovery: handler output crosses the client boundary only after a normal return Buffered writers preserve net/http first-WriteHeader and implicit-200 semantics	HTTP-06	4 min	2026-09-20

Phase 6 Plan 09: Transactional Panic Recovery Summary

Shared transactional response buffering now prevents house and raw routes from leaking partial status, headers, or body bytes when a handler panics.

Performance

• Duration: 4 min
• Started: 2026-09-20T19:02:14Z
• Completed: 2026-09-20T19:06:12Z
• Tasks: 1 TDD task
• Files modified: 2

Accomplishments

• Added a private bufferedResponse that records headers, the first status, and body bytes without touching the destination writer.
• Changed recoverJSON and recoverBare to discard all buffered route output on panic and emit only their locked opaque JSON or bare 500 contracts.
• Added adversarial real-route tests that write 202, a secret header, and secret body bytes before panicking, plus success coverage for explicit status, repeated WriteHeader, and implicit 200 behavior.

Task Commits

TDD commits were created atomically:

1. RED: Add failing partial-write panic and successful-buffer regressions - f6ba67a (test)
2. GREEN: Buffer route responses before panic recovery - 93d63c3 (fix)

Plan metadata: this summary commit

Files Created/Modified

• surf/router.go - Shared buffered response writer and transactional house/raw recovery wrappers.
• surf/router_test.go - Partial-write disclosure regressions and successful buffered response semantics.

Decisions Made

• Both recovery wrappers use the same buffer implementation so raw and house routes differ only in their panic fallback body contract.
• Flush is intentionally a no-op; exposing or flushing the destination before handler completion would invalidate the security boundary.
• Success commits defensively copy buffered header slices and replace only the keys written by the route, retaining unrelated outer-wrapper headers.

Deviations from Plan

None - plan executed exactly as written.

Issues Encountered

The sandbox's default Go build cache was read-only, so verification used the task-local GOCACHE=/tmp/summercms-06-09-gocache. This did not affect source or test behavior.

Verification

• go test ./surf -run 'Test.*(Recover|Panic|BufferedResponse|RawGroup)' -count=1 -race -short - pass
• go vet ./surf - pass
• go test ./surf -count=1 -race -short - pass
• Source inspection confirms both wrappers pass only bufferedResponse to next; the destination is written only by success commit or the panic fallback.
• House panic response is exactly {"error":true,"message":"Internal server error"} with no secret header/body; raw panic response is status 500 with zero body and empty Content-Type.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• HTTP-06's opaque/bare panic boundary is now safe even after handlers attempt partial writes.
• Raw OAuth routes in Phase 8 and remaining house routes in Phases 12-14 can rely on the same transactional recovery contract.
• No blockers.

Known Stubs

None.

Self-Check: PASSED

• FOUND: surf/router.go, surf/router_test.go
• FOUND: commits f6ba67a, 93d63c3
• PASS: targeted race regressions, go vet ./surf, and full surf race suite

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Phase: 06-http-routing-auth-groups-and-rate-limiting Completed: 2026-09-20