Deno v1.42.2 — Release Notes & Engineering Impact

Source available — automated, not human-reviewed

Component: deno · Channel: stable. Automated analysis, not a compatibility certification. How this works.

Analysis updated: 2026-11-01.

Compatibility not verified — check source notes

📄 .MD

✨ Features 1 ⚡ Improvements 6 🔧 Bug Fixes 6

⚡ Executive Summary (TL;DR)

Deno v1.42.2. Source highlight: FUTURE(ext/fs): make `Deno.FsFile` constructor illegal (#23235)

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Who Does This Impact? (Role-Based Analysis)

💻 Software Engineers & Devs

Check the source notes against the package and APIs you use before upgrading.

📊 Product & Engineering Leads

Use the documented changes to assess relevance to your product; release frequency alone is not a quality measure.

⚙️ DevOps & Security

Verify the target version, runtime requirements and rollback procedure in the official documentation.

✨ New Features & Capabilities (1)

feat(lsp): respect nested deno.json for fmt and lint config (#23159)

⚡ Performance & Enhancements (6)

perf(lsp): Don't retain `SourceFileObject`s in `sourceFileCache` longer than
perf(lsp): More granular locking of `FileSystemDocuments` (#23291)
perf(lsp): Only evict caches on JS side when things actually change (#23293)
perf(lsp): cache ts config in isolate until new project version (#23283)
perf(lsp): don't keep remote module ast's in memory (#23230)
perf(lsp): don't pass remote modules as tsc roots (#23259)

🔧 Bug Fixes & Patches (6)

fix(cli): Enforce a human delay in prompt to fix paste problem (#23184)
fix(cli): fix deadlock in test writer when test pipe is full (#23210)
fix(cli): update `deno doc` help to fit current usage (#23224)
fix(ext/fs): account for all ops in leak checks (#23300)
fix(ext/http): Make `Deno.serveHttp()` work when proxying (#23269)
fix(ext/net): Improve ts types for network APIs (#23228)

📄 View Raw Release Notes (Original Developer Log)

### 1.42.2 / 2024.04.11 - FUTURE(ext/fs): make `Deno.FsFile` constructor illegal (#23235) - FUTURE(ext/fs): remove `Deno.FsWatcher.prototype.rid` (#23234) - FUTURE(ext/net): remove `Deno.(Conn|TlsConn|Listener|TlsListener|UnixConn).prototype.rid` (#23219) - FUTURE: enable BYONM by default (#23194) - FUTURE: override byonm with nodeModulesDir setting (#23222) - FUTURE: remove deprecated APIs within workers (#23220) - feat(lsp): respect nested deno.json for fmt and lint config (#23159) - fix(cli): Enforce a human delay in prompt to fix paste problem (#23184) - fix(cli): fix deadlock in test writer when test pipe is full (#23210) - fix(cli): update `deno doc` help to fit current usage (#23224) - fix(ext/fs): account for all ops in leak checks (#23300) - fix(ext/http): Make `Deno.serveHttp()` work when proxying (#23269) - fix(ext/net): Improve ts types for network APIs (#23228) - fix(ext/node): Add "module" to builtinsModule (#23242) - fix(ext/node): Add fs.readv, fs.readvSync (#23166) - fix(ext/node): MessagePort works (#22999) - fix(ext/node): Support returning tokens and option defaults in `node:util.parseArgs` (#23192) - fix(ext/node): `node:vm` contexts (#23202) - fix(ext/node): count MessagePort message listeners in hasMessageEventListener (#23209) - fix(ext/node): hostname is valid IPv4 addr (#23243) - fix(ext/node): implement MessagePort.unref() (#23278) - fix(ext/node): improve AsyncLocalStorage api (#23175) - fix(ext/node): out-of-order writes of fs.createWriteStream (#23244) - fix(ext/node): patch MessagePort if provided as workerData (#23198) - fix(ext/node): polyfill node:domain module (#23088) - fix(ext/tls): add support EC private key (#23261) - fix(lsp): Remove client-facing format failure warning (#23196) - fix(lsp): respect DENO_FUTURE for BYONM config (#23207) - fix(runtime): fix Windows permission prompt (#23212) - fix: prevent cache db errors when deno_dir not exists (#23168) - perf(lsp): Don't retain `SourceFileObject`s in `sourceFileCache` longer than necessary (#23258) - perf(lsp): More granular locking of `FileSystemDocuments` (#23291) - perf(lsp): Only evict caches on JS side when things actually change (#23293) - perf(lsp): cache ts config in isolate until new project version (#23283) - perf(lsp): don't keep remote module ast's in memory (#23230) - perf(lsp): don't pass remote modules as tsc roots (#23259) - perf(lsp): replace document registry source cache on update (#23311) - perf(lsp): use lockfile to reduce npm pkg resolution time (#23247) - perf(node): put pkg json into an `Rc` (#23156) - perf: reduce allocations in `MediaType::from_specifier` (#23190)

← Older Version Deno v1.42.1 Newer Version → Deno v1.42.3