Home / DEVTOOLS / Deno / v0.37.0
Deno v0.37.0stable Released Mar 23, 2020
⚠️ Breaking Change Impact Score: 7/10

Deno v0.37.0 — 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.

Breaking-change evidence from the source

  • - BREAKING CHANGE: FileInfo.len renamed to FileName.size (#4338)
  • - BREAKING CHANGE: Rename Deno.run's args to cmd (#4444)
Read the original context ↗
Source flags breaking changes — review applicability
📄 .MD
✨ Features 6 ⚡ Improvements 2 🔧 Bug Fixes 6 ⚠️ Breaking & Deprecations 2
⚡ Executive Summary (TL;DR)

Deno v0.37.0. Source highlight: BREAKING CHANGE: FileInfo.len renamed to FileName.size (#4338)

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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.

⚠️ Breaking Changes & Deprecations (2)

  • - BREAKING CHANGE: FileInfo.len renamed to FileName.size (#4338)
  • - BREAKING CHANGE: Rename Deno.run's args to cmd (#4444)

✨ New Features & Capabilities (6)

  • feat(ci): Releases should all use zip and LLVM target triples (#4460)
  • feat(console): Symbol.toStringTag and display Object symbol entries (#4388)
  • feat(std/node): Add chmod Node polyfill (#4358)
  • feat(std/node): Add node querystring polyfill (#4370)
  • feat(std/node): Node polyfill for fs.chown and fs.close (#4377)
  • feat(std/permissions): Add helper functions for permissions to std (#4258)

⚡ Performance & Enhancements (2)

  • perf: Optimize TextEncoder and TextDecoder (#4430, #4349)
  • refactor: Improve test runner (#4336, #4352, #4356, #4371)

🔧 Bug Fixes & Patches (6)

  • fix(std/http): Close open connections on server close (#3679)
  • fix(std/http): Properly await ops in a server test (#4436)
  • fix(std/http): Remove bad error handling (#4435)
  • fix(std/node): Node polyfill fsAppend rework (#4322)
  • fix(std/node): Stack traces for modules imported via require (#4035)
  • fix: Importing JSON doesn't work in bundles (#4404)
📄 View Raw Release Notes (Original Developer Log)
### Changes - BREAKING CHANGE: FileInfo.len renamed to FileName.size (#4338) - BREAKING CHANGE: Rename Deno.run's args to cmd (#4444) - feat(ci): Releases should all use zip and LLVM target triples (#4460) - feat(console): Symbol.toStringTag and display Object symbol entries (#4388) - feat(std/node): Add chmod Node polyfill (#4358) - feat(std/node): Add node querystring polyfill (#4370) - feat(std/node): Node polyfill for fs.chown and fs.close (#4377) - feat(std/permissions): Add helper functions for permissions to std (#4258) - feat(std/types): Provide types for React and ReactDOM (#4376) - feat(test): Add option to skip tests (#4351) - feat(test): Add support for jsx/tsx for deno test (#4369) - feat: Add mode option to open/create (#4289) - feat: Deno.test() sanitizes ops and resources (#4399) - feat: Fetch should accept a FormData body (#4363) - feat: First pass at "deno upgrade" (#4328) - feat: Prvode way to build Deno without building V8 from source (#4412) - feat: Remove `Object.prototype.__proto__` (#4341) - fix(std/http): Close open connections on server close (#3679) - fix(std/http): Properly await ops in a server test (#4436) - fix(std/http): Remove bad error handling (#4435) - fix(std/node): Node polyfill fsAppend rework (#4322) - fix(std/node): Stack traces for modules imported via require (#4035) - fix: Importing JSON doesn't work in bundles (#4404) - fix: Simplify timer with macrotask callback (#4385) - fix: Test runner ConnectionReset bug (#4424) - fix: chmod should throw on Windows (#4446) - fix: fetch closes unused body (#4393) - perf: Optimize TextEncoder and TextDecoder (#4430, #4349) - refactor: Improve test runner (#4336, #4352, #4356, #4371) - refactor: Remove std/testing/runner.ts, use deno test (#4397, #4392) - upgrade: Rust 1.42.0 (#4331) - upgrade: Rust crates (#4412) - upgrade: to rusty_v8 0.3.5 / v8 8.2.308 (#4364) ### Install / Upgrade **With Shell:** ```sh curl -fsSL https://deno.land/x/install/install.sh | sh -s v0.37.0 ``` **With PowerShell:** ```powershell iwr https://deno.land/x/install/install.ps1 -useb -outf install.ps1; .\install.ps1 v0.37.0 ```
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