Web Streams got a big performance pass on write, pump, and BYOB paths (
5d673d9, 539d6c4, 280dfbe, 423fb8b)
These commits reduce per-chunk allocations, add a sync-pull fast path, and serialize type:"direct" pulls on the JS reader path to avoid overlapping async pull() calls. They also improve heap snapshot labeling for stream internals, making stream-related memory leaks and retainer paths much easier to diagnose.
fetch() now re-evaluates proxy settings per redirect hop and accepts URL instances for proxy (b05b4fa, 3981e9b)
Redirects now re-check http_proxy / https_proxy / NO_PROXY at each hop instead of freezing the original decision, which fixes incorrect proxying across redirected URLs. The proxy option also now properly handles a URL instance in both fetch() and WebSocket, matching the docs and type definitions.
fetch() now rejects on option-conversion errors instead of throwing synchronously (e96a4d4)
If URL/init coercion or option getters throw, Bun now returns a rejected promise per WHATWG fetch semantics instead of escaping synchronously. This closes a compatibility gap with Node/undici and makes error handling around fetch() much more predictable.
Bun.serve fixed several response-stream and error-handler edge cases (0b489d0, dbe00e3, 4bfcc0f, 124d52c)
error() now receives a pending-promise rejection reason of null verbatim, isn’t re-run after the status line is already committed, and can safely return a streaming body. HEAD requests to streaming responses now cancel the body correctly so underlying resources are released instead of leaking.
socket and net writes now treat transient ENOBUFS/ENOMEM as would-block (fc865b3)
Transient kernel send failures no longer become fatal connection errors; Bun keeps buffered bytes and retries later. That brings node:net behavior closer to expectations under resource pressure and fixes a class of flaky write failures.
Other misc changes
child_process.stdinstaysnullafter exit for non-পiped stdio configs.util.parseArgs()now treats null top-level boolean flags as absent.- Build script
--helpTDZ ReferenceError fix. - GC/heap-analysis plumbing and stream internal refactors.
- Socket callback lifetime/GC refactor and related internal cleanup.