Cleanup of the Bedrock adapter (ba1705d) following parallel review
passes for code reuse, code quality, and efficiency.
- Drop dead `text` join helper and unused `TextPart` import.
- Schema-validate `model.native.aws_credentials` instead of seven
manual `typeof` guards in `credentialsFromInput`. Removes the
unsafe `as Record<string, unknown>` cast and fixes the dead
`native?.region` fallback (the `model()` constructor only writes
`aws_region`).
- Skip the JSON.parse → JSON.stringify → Schema.fromJsonString triple
round-trip in the frame consumer. The eventstream codec already
hands us a UTF-8 payload; parse once and feed the wrapped object
directly to `Schema.decodeUnknownSync(BedrockChunk)`.
- Replace O(n²) buffer concat in `consumeFrames` with a cursor-based
state `{ buffer, offset }`. Compaction happens once per network
chunk via `appendChunk` instead of per frame; frame slicing is
zero-copy via `subarray`. Bounded buffer growth regardless of
stream length.
- Rename `ParserState.finishReason` → `pendingStopReason` (raw
string) and defer the `mapFinishReason` call to the single emit
site, plus the `onHalt` fallback. Tightens the helper's signature
to `(reason: string)` so the chunk-typed `messageStop.stopReason`
flows through without the optional widening.
- Restructure `signRequest` to take an object parameter (was four
positional args), and replace the manual `forEach`-into-record with
`Object.fromEntries(signed.headers.entries())`.
- Inline single-use `status` and `useTools` variables.
- Widen `fixedResponse` to accept `ConstructorParameters<Response>[0]`
so binary fixtures (`Uint8Array`, streams) flow without casts. The
Bedrock test's `fixedBytes` helper now wraps it cleanly.
- Tidy `captureResponseBody` into a ternary returning the union shape
directly so the call site spreads the captured object without
reaching for `bodyEncoding` explicitly.
Verified: `bun typecheck` clean, 106 pass / 0 fail / 0 skip
(unchanged from before the refactor).
Simplify pass after the typed ToolRuntime initial drop. Findings from a
parallel review (code reuse + quality + perf):
src/tool.ts
- Tool now carries memoized decode/encode codecs and a precomputed
ToolDefinition, derived once at tool() construction time. The runtime no
longer rebuilds Schema closures or JSON Schema docs per call/per run.
- Constrains parameters/success to Schema.Codec<T, any, never, never> so
the codecs have no service requirements. Drops the 'as unknown as' casts
the runtime needed previously.
- Fixes a latent bug: schemas with $ref now correctly emit $defs on
ToolDefinition.inputSchema (toJsonSchemaDocument's definitions were
silently dropped before).
src/tool-runtime.ts
- Uses LLMRequest constructor instead of 'as LLMRequest' casts.
- Default tool dispatch concurrency is 10 (was 'unbounded'); exposed via
RunOptions.concurrency. Unbounded is still available for handlers that
do not share a saturable resource.
- Drops dead 'usage' state, the single-use Dispatched interface, and the
DEFAULT_MAX_STEPS constant per the inline-when-used style rule.
- accumulate() now factors text-delta and reasoning-delta into one helper.
test/lib/openai-chunks.ts (new)
- Shared deltaChunk / usageChunk / toolCallChunk / finishChunk helpers.
test/lib/http.ts
- scriptedResponses moved here from tool-runtime.test.ts so future
multi-step adapter tests can reuse it. Also picks up parallel work that
swapped HandlerInput to a 'respond' callback for cleaner Response
construction.
test/tool-runtime.test.ts
- Uses LLMEvent.guards for typed event filtering instead of cast-and-check.
- Concurrent test now uses sseEvents + deltaChunk instead of a hand-rolled
body string.
Includes parallel callsite updates in test/adapter.test.ts and
test/provider/openai-compatible-chat.test.ts that adopt the 'respond' API
in lib/http.ts.
- Structurally match recorded requests by canonical JSON so non-deterministic
field ordering doesn't break replay.
- Pluggable header allow-list and body redaction hook on the record/replay
layer, so adapters with non-default auth (Anthropic, Bedrock) can plug in
without touching this file.
- Move the cassette-name dedupe set inside recordedTests() so two describe
files using different prefixes can run in parallel.
- Replace inline SSE template literals and per-file HTTP layers with shared
test/lib helpers (sseEvents, fixedResponse, dynamicResponse, truncatedStream).
- Tighten recorded-test assertions to exact text and usage so adapter parser
regressions surface immediately instead of passing fuzzy length>0 checks.
- Add cancellation and mid-stream transport-error tests for the OpenAI Chat
adapter.
- Add cross-phase patch tests that verify each phase sees an updated
PatchContext and that same-order patches sort deterministically by id.
Kit Langton