Deno v1.39.3 — 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 2 🔧 Bug Fixes 6

⚡ Executive Summary (TL;DR)

Deno v1.39.3. Source highlight: feat(unstable): fast subset type checking of JSR dependencies (#21873)

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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(unstable): fast subset type checking of JSR dependencies (#21873)

⚡ Performance & Enhancements (2)

perf(lsp): use host-owned cache for auto-import completions (#21852)
perf: skip expanding exclude globs (#21817)

🔧 Bug Fixes & Patches (6)

fix(ci): update copright year for _fs_cp.js (#21803)
fix(cli): update import map url (#21824)
fix(compile): preserve granular unstable features (#21827)
fix(ext): enable prefer-primordials for internal TypeScript (#21813)
fix(ext/crypto): initial support for p521 in `generateKey` and `importKey`
fix(ext/node): add WriteStream.isTTY (#21801)

📄 View Raw Release Notes (Original Developer Log)

### 1.39.3 / 2024.01.12 - feat(unstable): fast subset type checking of JSR dependencies (#21873) - fix(ci): update copright year for _fs_cp.js (#21803) - fix(cli): update import map url (#21824) - fix(compile): preserve granular unstable features (#21827) - fix(ext): enable prefer-primordials for internal TypeScript (#21813) - fix(ext/crypto): initial support for p521 in `generateKey` and `importKey` (#21815) - fix(ext/node): add WriteStream.isTTY (#21801) - fix(ext/node): add fs.cp, fs.cpSync, promises.cp (#21745) - fix(ext/websocket): pass on uncaught errors in idleTimeout (#21846) - fix(fast_check): analyze identifiers in type assertions/as exprs (#21899) - fix(kv): improve .listenQueue types (#21781) - fix(lsp): implement host.getGlobalTypingsCacheLocation() (#21882) - fix(lsp): show test code lens for template literal names (#21798) - fix(lsp): use a dedicated thread for the parent process checker (#21869) - fix(registry): wait for already pending publish (#21663) - fix(task): do not eagerly auto-install packages in package.json when `"nodeModulesDir": false` (#21858) - fix(unstable/tar): skip node_modules, .git, and config "exclude" (#21816) - fix(web): use rustyline for prompt (#21893) - fix: add EventSource typings (#21908) - fix: android support (#19437) - fix: cjs export rewritten to invalid identifier (#21853) - fix: update deno_lint and swc (#21718) - perf(lsp): use host-owned cache for auto-import completions (#21852) - perf: skip expanding exclude globs (#21817)

← Older Version Deno v1.39.2 Newer Version → Deno v1.39.4