Bundler import-graph traversal goes iterative (
483fd42)
The bundler replaces several recursive JS import-graph walks with explicit-stack DFS/worklist passes. This avoids deep recursion hazards and should improve scalability on large graphs while preserving traversal order.
Node HTTP response writes now avoid copying large payload tails (934fa55)
res.write() can now hold unwritten data by reference instead of copying it into uWS backpressure storage, matching Node’s behavior for large writes. That cuts allocation pressure and removes a major performance cliff for big streaming responses.
Node http server finish/pipeline handling is fixed (78f3a46)
Bun now registers the socket-detach finish listener before emitting request, and defers the pipeline-advance/detach split so keep-alive middleware doesn’t lose the socket or double-advance the queue. This fixes a real regression in middleware-heavy servers like vite preview.
process.on('beforeExit') no longer fires after fatal uncaught exceptions (b0925d7)
The runtime now skips beforeExit when the process is terminating due to a fatal uncaught exception, aligning with Node’s documented behavior. That removes a surprising callback path during crash handling.
bun:test expectation diffs stop eating literal <...> text (f44d5fe)
The matcher formatting pipeline now preserves user data instead of interpreting every <tag>-looking span as markup. This fixes misleading failure output for tests whose expected/received values contain HTML-like text.
Zlib gains dictionary support and Node-compatible reset behavior (
19d8ec0)
Bun’s brotli and zstd paths now support dictionaries, and reset() behavior is tightened to match Node. The test coverage jump here suggests this closes several real compatibility gaps in compression-heavy code.
Web Streams compatibility expands substantially (b70524e)
Another 17 Node web-streams tests were vendored, bringing Bun much closer to upstream coverage. The work also fixes a batch of stream/encoding edge cases discovered by those tests.
Server callbacks are now rooted and traced correctly (1bd1783)
This refactor changes how server-level JS callbacks are managed so they stay alive through GC and are released deterministically. It also updates several server internals and adds broad regression coverage, indicating a high-risk correctness fix around server lifecycle and callback safety.
Spawns keep maxBuffer enforcement after stdout/stderr is touched (91462ff)
Accessing proc.stdout/proc.stderr no longer disables the maxBuffer kill path. That fixes a hang and restores the expected “kill on overflow” behavior for piped subprocesses.
Bun.serve static responses stop emitting duplicate Date headers (e8f5c6a)
Static routes now avoid adding a second Date header when the user’s Response already has one. That matters for cache correctness because Date is a singleton field and duplicate values can break freshness logic.
node:http now detaches keep-alive sockets at the right time (78f3a46)
The rewritten finish handling also ensures middleware that rewires res.on('finish') can’t swallow Bun’s internal socket cleanup. This resolves a socket-assignment crash on the second keep-alive request in common compression middleware patterns.
Other misc changes
- Node parity fixes across
dns,events,sqlite,assert,util.MIMEType,stream,fs/promises,os.networkInterfaces,napi,semver,dotenv,shell,ffi,bun:serve,bun.Transpiler,bun.color,bun:mmap,bun.gunzipSync/inflateSync, andredis. - Performance/internal refactors in CSS parsing/minification, source maps, semver parsing, resolver path handling, collections, js_parser, installer metadata scanning, and HTTP/2/3 lookup paths.
- Root CA bundle refresh and certificate generator fix for Izenpe.com.
- Tests and vendored Node fixtures added or updated across multiple subsystems.