Migrate utility layer to HTTP types (PR 11)

[prk-Jr]

Summary

• Migrate the PR11 utility layer off direct fastly::Request/fastly::Response usage so core helpers can operate on http::{Request, Response} and edgezero_core::Body.
• Add a temporary compat bridge at Fastly boundaries so handlers and integrations can keep working while later migration PRs move the remaining call stack.
• Lock in the migration with focused compat tests and a guard test that prevents the migrated utility modules from drifting back to Fastly request/response types.

Changes

File	Change
Cargo.toml	Add the workspace mime dependency used by migrated HTTP response helpers.
Cargo.lock	Record the new mime dependency.
crates/trusted-server-adapter-fastly/src/main.rs	Route forwarded-header sanitization and basic-auth response conversion through the new compat boundary.
crates/trusted-server-core/Cargo.toml	Add the core crate's mime workspace dependency.
crates/trusted-server-core/src/auction/endpoints.rs	Convert auction utility calls to use the HTTP request compat bridge for EC ID and consent handling.
crates/trusted-server-core/src/auth.rs	Migrate basic-auth enforcement to http::Request/Response and update tests to HTTP builders.
crates/trusted-server-core/src/compat.rs	Add Fastly-to-HTTP request/response conversions plus temporary Fastly boundary shims for headers, cookies, and EC cookie handling.
crates/trusted-server-core/src/consent/extraction.rs	Migrate consent signal extraction to http::Request<EdgeBody>.
crates/trusted-server-core/src/consent/mod.rs	Move consent pipeline input types and tests onto HTTP request types.
crates/trusted-server-core/src/cookies.rs	Migrate cookie parsing/forwarding and EC cookie response helpers to HTTP request/response types; document and test target Cookie append semantics.
crates/trusted-server-core/src/edge_cookie.rs	Add HTTP request EC ID helpers so migrated callers can reuse an existing HTTP request without rebuilding Fastly headers.
crates/trusted-server-core/src/http_util.rs	Migrate request/response helpers to HTTP types, preserve duplicate headers, and keep request-info logic on ClientInfo.
crates/trusted-server-core/src/integrations/lockr.rs	Use Fastly compat shims for header/cookie forwarding at the integration boundary.
crates/trusted-server-core/src/integrations/permutive.rs	Use Fastly compat shims for custom-header forwarding at the integration boundary.
crates/trusted-server-core/src/integrations/prebid.rs	Bridge request-info construction and cookie forwarding through compat conversions.
crates/trusted-server-core/src/integrations/registry.rs	Use compat conversions for EC ID generation and EC cookie response handling.
crates/trusted-server-core/src/lib.rs	Export the compat module and add migration guard tests.
crates/trusted-server-core/src/migration_guards.rs	Add a regression test preventing migrated utility modules from reintroducing direct Fastly request/response types.
crates/trusted-server-core/src/publisher.rs	Route TSJS serving, request-info extraction, consent handling, and EC cookie writes through compat conversions.
crates/trusted-server-core/src/request_signing/endpoints.rs	Switch JSON content-type constants to mime::APPLICATION_JSON.

Closes

Closes #492

Test plan

• cargo test --workspace
• cargo clippy --workspace --all-targets --all-features -- -D warnings
• cargo fmt --all -- --check
• JS tests: cd crates/js/lib && npx vitest run
• JS format: cd crates/js/lib && npm run format
• Docs format: cd docs && npm run format
• WASM build: cargo build --package trusted-server-adapter-fastly --release --target wasm32-wasip1
• Manual testing via fastly compute serve
• Other: focused Rust verification with cargo test --package trusted-server-core compat -- --nocapture, cargo test --package trusted-server-core http_util -- --nocapture, cargo test --package trusted-server-core request_signing -- --nocapture, and cargo test --package trusted-server-core migration_guards -- --nocapture
• Other: local cd crates/js/lib && npx vitest run currently fails before test execution with ERR_REQUIRE_ESM in html-encoding-sniffer -> @exodus/bytes/encoding-lite.js; leaving CI to capture the current JS environment issue.

Hardening note

This PR does not add any new config-derived regex or pattern compilation paths. Basic auth still surfaces invalid enabled handler regex configuration as an error rather than panicking, covered by auth::tests::returns_error_for_invalid_handler_regex_without_panicking alongside the existing settings startup validation tests.

Checklist

• Changes follow CLAUDE.md conventions
• No unwrap() in production code — use expect("should ...")
• Uses project logging macros (not println!)
• New code has tests
• No secrets or credentials committed

[aram356]

Summary

PR introduces compat.rs as a temporary Fastly↔http bridge and migrates six utility modules (auth, cookies, synthetic, http_util, consent/extraction, consent/mod) off fastly::Request/fastly::Response. Prior approvals (2026-04-14) predate the latest commit ae402ff (2026-04-15), which renamed from_fastly_request_ref → from_fastly_headers_ref, dropped a redundant case check in copy_fastly_custom_headers, and switched forward_cookie_header to get_all + append. The round-2 fixes for duplicate-header preservation are clean, but a few concerns remain — notably a new runtime-panic surface at the edge and unused compat helpers that arrived before their callers.

Blocking

🔧 wrench

• New edge-wide panic surface on URL parsing: compat::build_http_request calls .parse().expect(...) on every bridged request. http::Uri is stricter than Fastly's internal url::Url, so a URL Fastly accepts but http::Uri rejects panics the entire edge handler before auth can run. Previously enforce_basic_auth used req.get_path() with no re-parse. (crates/trusted-server-core/src/compat.rs:14-31)

Non-blocking

🤔 thinking

• Redundant compat conversion on the prebid hot path: request_bids (prebid.rs:1012) and to_openrtb (prebid.rs:713) both convert the same context.request in the same auction flow — pull up once and thread through.

♻️ refactor

• Three compat functions ship without callers: from_fastly_request, to_fastly_request, and from_fastly_response are only referenced from their own tests. CLAUDE.md says "Don't design for hypothetical future requirements. No half-finished implementations either." Ship in the PR that uses them. (crates/trusted-server-core/src/compat.rs:40, 61, 90)

🌱 seedling / 📌 out of scope / ⛏ nitpick

• 📌 Redundant conversion at the auction boundary: acknowledged by TODO at auction/formats.rs:93-95; accepted cost of incremental migration.
• 🌱 sanitize_fastly_forwarded_headers get-then-remove: remove_header is idempotent; the get_header guard exists only for the debug log. (compat.rs:129-136)
• ⛏ forward_cookie_header panics on HeaderValue::from_str: fires only on already-validated input, but a try_from + skip keeps failure local to the function. (cookies.rs:156-186)

CI Status

• fmt: PASS
• clippy: PASS
• rust tests: PASS (841/841)
• browser integration / integration / artifacts (GitHub Actions): PASS

[aram356]

Summary

PR 11 of the EdgeZero migration: lifts the utility layer (auth, cookies, http_util, consent) off fastly::{Request, Response} onto http::{Request, Response}<EdgeBody>, with a compat bridge module that lets non-migrated callers keep working. The shape of the migration is sound and the new migration_guards test is a strong regression backstop. The principal concerns are CI (clippy fails when run against main) and a migrated-but-untested code path that will silently change behavior in the next PR.

Blocking

🔧 wrench

• Clippy fails: cookies::set_ec_cookie missing # Panics (crates/trusted-server-core/src/cookies.rs:258)
• Clippy fails: cookies::expire_ec_cookie missing # Panics (crates/trusted-server-core/src/cookies.rs:277)
• Migrated cookies::forward_cookie_header has no callers and no tests — semantics diverge from compat::forward_fastly_cookie_header (get_all vs first-only) (crates/trusted-server-core/src/cookies.rs:152)

CI didn't catch the clippy regressions because format.yml only triggers on PRs whose base is main. PR 623's base is the PR 10 feature branch, so the clippy + fmt gate was bypassed entirely.

Non-blocking

🤔 thinking

• compat is pub mod compat — exposed as public API despite being PR 15 removal scaffolding (crates/trusted-server-core/src/lib.rs:38)
• from_fastly_headers_ref # Panics doc is inaccurate — claims URL parse panics but uses unwrap_or_else fallback (crates/trusted-server-core/src/compat.rs:46)
• to_fastly_response silently truncates EdgeBody::Stream — latent risk as more callers migrate (crates/trusted-server-core/src/compat.rs:65)

♻️ refactor

• compat::expire_fastly_synthetic_cookie hardcodes cookie attributes instead of reusing cookies::ec_cookie_attributes — DRY drift on security-sensitive code (crates/trusted-server-core/src/compat.rs:145)
• compat uses old "synthetic" naming instead of "ec" — inconsistent with the recent EC rename (crates/trusted-server-core/src/compat.rs:118)

⛏ nitpick

• from_fastly_headers_ref URI fallback to "/" swallows malformed URLs silently — at minimum log a warning (crates/trusted-server-core/src/compat.rs:17)

👍 praise

• migration_guards.rs — concise regression test with well-justified limitations
• PrebidAuctionProvider::to_openrtb request_info refactor — single source of truth, real readability win

CI Status

• fmt: PASS (cargo fmt --all -- --check)
• clippy: FAIL — 2 errors (missing_panics_doc on set_ec_cookie / expire_ec_cookie), bypassed by base branch routing
• rust tests: PASS (cargo test --workspace)
• integration tests (GitHub Actions): PASS (3/3)

[aram356]

Summary

PR 11 of the EdgeZero migration: lifts six utility modules (auth, cookies, http_util, consent/extraction, consent/mod, plus the JSON content-type in request_signing/endpoints) off fastly::{Request, Response} onto http::{Request, Response}<EdgeBody> with a compat bridge for non-migrated callers. CI is green across all 13 jobs and clippy is clean against main locally. All blocking findings from the prior CHANGES_REQUESTED reviews are resolved — set_ec_cookie/expire_ec_cookie panics docs added, forward_cookie_header now has dedicated tests for the multi-Cookie and non-UTF-8 paths, and the *_synthetic_cookie → *_ec_cookie rename keeps the EC terminology consistent. Filing non-blocking observations only; a clean approve will follow.

Non-blocking

🤔 thinking

• forward_cookie_header source/target divergence: source-side get_all vs get_header is tested, but target-side append vs set is unflagged and would change behavior for any future caller that seeds to with a pre-existing Cookie header (crates/trusted-server-core/src/cookies.rs:169).
• TSJS path allocates the response body twice through the serve_static_with_etag → compat::to_fastly_response round-trip; disappears in PR 13/14 (crates/trusted-server-core/src/publisher.rs:140).

🌱 seedling

• Double http::Request build per request in handle_publisher_request and handle_auction — both build http_req explicitly, then pass &req (fastly) to get_or_generate_ec_id, which rebuilds it inside get_ec_id (crates/trusted-server-core/src/edge_cookie.rs:120).
• compat::set_fastly_ec_cookie duplicates the validate-then-build control flow of cookies::set_ec_cookie. A cookies::try_build_ec_cookie_value helper would dedupe both append-paths (crates/trusted-server-core/src/compat.rs:156).

📝 note

• PR description "Changes" table is out of sync with the diff: lists auction/formats.rs, integrations/testlight.rs, proxy.rs, synthetic.rs which aren't in git diff main...HEAD (folded into PR 9/10 merges). Update before merge for accuracy.

👍 praise

• All 9 prior findings addressed correctly — panics docs, EC rename, attribute reuse, #[doc(hidden)], debug_assert! on stream truncation, URI parse warning, plus comprehensive tests for the divergent code paths.
• migration_guards ban list extension to fastly::mime::APPLICATION_JSON keeps the regression net tight (crates/trusted-server-core/src/migration_guards.rs:42).
• PrebidAuctionProvider::to_openrtb request_info refactor — lifts RequestInfo::from_request to prepare_request, eliminating a duplicate construction (crates/trusted-server-core/src/integrations/prebid.rs:1007).

CI Status

• fmt: PASS
• clippy: PASS (verified locally with --workspace --all-targets --all-features -- -D warnings)
• rust tests: PASS
• vitest: PASS
• browser integration tests: PASS
• format-typescript / format-docs: PASS