Web Streams got multiple hot-path speedups
da93007, 02b41b4, f8f5443, 003c72e, and b37f1be collectively cut per-chunk allocations, remove synchronous microtask hops, and hoist reusable handlers in ext/web/06_streams.js. These changes target the core body/stream machinery used by fetch, Response bodies, and stream piping, so they should improve throughput and reduce memory churn across a wide range of workloads.
Node TLS write paths were made dramatically cheaper
90760e7 removes accidental quadratic copying in node:tls by tracking progress through a pending cleartext buffer instead of reallocating the unwritten tail on each chunk. The same commit also switches decrypted/encrypted chunk materialization to zero-copy ArrayBuffer backing stores, which slashes memcpy overhead and peak latency on large socket writes.
Node net writes now avoid redundant buffer copies
aa1380b makes async Buffer writes on the stream_wrap path zero-copy by queueing an iovec directly over the ArrayBuffer backing store. That lowers both write latency and peak RSS for large socket.write(buffer) calls in node:net.
fetch now reports transport failures in Node’s shape
4a08965 changes transport-level fetch errors to throw TypeError: fetch failed with the low-level detail preserved in .cause, instead of surfacing reqwest’s raw message directly. This aligns Deno with Node/undici and also improves error suggestion handling by following the cause chain.
Deno.serve stream errors and non-Uint8Array chunks are handled correctly
01d29aa fixes response-body stream error propagation so the original stream error reaches the resource backing Deno.serve and onError, and adds regression coverage for invalid non-Uint8Array chunks. This closes a hang/error-reporting gap in server responses that could previously mask the real failure.
Cache.keys() is now implemented
ed8c592 adds the missing Cache.keys() API across the implementation, type definitions, and tests. It returns request keys in insertion order and supports optional request filtering, filling a notable Service Worker API gap.
fs.glob() can now follow symlinks
2886aec adds a new followSymlinks option to Node-compatible fs.glob(), backed by realpath/stat helpers and caching. That brings the polyfill closer to Node’s behavior for symlink-heavy projects.
Heap snapshots can now be triggered near V8 heap limits
da1897d implements v8.setHeapSnapshotNearHeapLimit() for node:v8, including on-disk snapshot naming and permission-aware file creation. This is a major debugging feature for out-of-memory situations and mirrors Node’s near-OOM snapshot behavior.
Node child processes now support inherited fd 3 pipes
4b3cf68 teaches spawned Deno Node children about extra inherited stdio descriptors so fd-based APIs can see them correctly. This fixes a real compatibility issue for code that relies on supplemental pipes during child-process startup.
deno desktop now respects --exclude-unused-npm
56891e1 wires the compile flag through desktop builds so unused npm packages no longer have to be embedded in managed snapshots. That should reduce desktop app bundle size when the flag is enabled.
OTEL attribute value length limiting is now honored
d6f01cf implements the OpenTelemetry span-attribute length limit env vars, truncating long string values and string-array entries while preserving existing defaults. This brings telemetry behavior in line with the SDK config knobs.
Other misc changes
- Refactors to migrate several serde_v8 conversion paths to
deno_core::convert(8915825,08de6f9,faf038e) - Coverage fixes for line/branch counting (
584a182,34e593a) - Install/lifecycle/jsr and package-copying fixes (
a885095,f1717fc,fe22eef) - LSP/runtime startup fix to avoid a CPU busy loop (
ac8677d) - WPT epoch update and docs additions (
75d16d0,88f2ff6) - Smaller fetch, fs, crypto, lint, and worker tweaks (
2e68b96,c1f2ce3,9a466c7,d67bba7,c812bd6, and others)