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Matteo Collina
28995396b2
The spec's [[backpressureChangePromise]] is only ever observed by the transform source pull algorithm (settles when backpressure next becomes true) and by a sink write arriving under backpressure (settles when it next becomes false), both internal. Replace the promise record with direct continuation delivery: a parked pull is completed by enqueueing the readable controller's pull-fulfilled step on the shared resolved promise, and a parked write by a cached per-stream continuation that resolves the sink promise with the perform-transform promise, so adoption reproduces the previous derived-chain settle depth exactly. Each delivery lands at the same microtask position as the old record's reaction. transformStreamDefaultControllerPerformTransform now mirrors the reference implementation's promiseCall().then(undefined, rejection steps) directly instead of running an async wrapper pair per chunk: the transformer.transform callback is wrapped raw, a non-thenable result reuses the shared resolved promise, and a synchronous throw is delivered through a rejected promise, keeping the error timing inside a reaction. A pipe-through benchmark is added since the suite had no transform-throughput row. pipeThrough passthrough improves by ~8% and a writer-driven transform loop by ~14%; the pipe-to and read families are unchanged. Signed-off-by: Matteo Collina <hello@matteocollina.com> PR-URL: https://github.com/nodejs/node/pull/65143 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>