DENO-2.9.0 release notes and known issues

Summary

2.9.0 / 2026.06.25 Read more: http://deno.com/blog/v2.9 feat(bundle): add --declaration flag to generate rolled-up .d.ts files ( #33838 ) feat(cli): add deno link and deno unlink subcommands ( #34359 ) feat(cli): add deno watch subcommand ( #35301 ) feat(cli): add deno list subcommand to list declared dependencies ( #34972 ) feat(cli): auto-migrate pnpm-workspace.yaml on resolution failure ( #34993 ) feat(cli): provide a node on PATH when Node.js is not installed ( #34969 ) feat(compile): persist Web Storage/KV in a per-app data directory ( #34618 ) feat(coverage): add configurable coverage thresholds ( #35056 ) feat(desktop): --compress for self-extracting app bundles ( #35420 ) feat(desktop): add Linux .deb and .rpm installer output formats ( #35296 ) feat(desktop): add Windows .msi installer output format ( #35378 ) feat(desktop): autodetect Vite framework ( #35470 ) feat(desktop): default UI backend to webview ( #35442 ) feat(ext/crypto): support remaining modern WebCrypto algorithms ( #35223 ) feat(ext/http): deprecation warning for legacy request abort ( #34397 ) feat(ext/net): implement Happy Eyeballs for Deno.connect and Deno.connectTls ( #31726 ) feat(ext/node): implement node:test mock.module ( #35329 ) feat(ext/node): implement node:test mock.timers ( #33946 ) feat(ext/web): web locks api ( #31166 ) feat(fmt): add sortNamedImports and sortNamedExports options ( #33313 ) feat(fmt): infer config from .editorconfig ( #34071 ) feat(fmt): use lax-css for CSS, SCSS, and Less ( #35160 ) feat(fmt): use lax-markup for HTML, XML, SVG, and components ( #35174 ) feat(fmt): use lax-sql for SQL formatting ( #35161 ) feat(http): allow disabling serve compression ( #35253 ) feat(http): disable Deno.serve automatic compression by default ( #35486 ) feat(install): create node_modules for workspace members ( #34970 ) feat(install): seed deno.lock from bun.lock ( #35394 ) feat(install): seed deno.lock from package-lock.json ( #35330 ) feat(install): seed deno.lock from pnpm-lock.yaml ( #35346 ) feat(install): seed deno.lock from yarn.lock ( #35350 ) feat(install): warn on package.json engines mismatch ( #34225 ) feat(lockfile): auto-resolve git merge conflicts in deno.lock ( #34726 ) feat(lsp): add inferred type request ( #35099 ) feat(napi): implement Node-API version 10 ( #35270 ) feat(node): bump reported process.version to v26.3.0 ( #34747 ) feat(npm): install jsr deps into node_modules via npm-compat registry ( #35029 ) feat(npm): publishing-trust ranking and no-downgrade trust policy ( #34927 ) feat(runtime): add request_builder_hook for fetch token and cdn-loop headers ( #35088 ) feat(task): add --if-present flag to deno task ( #35315 ) feat(task): add --jobs/--concurrency flag to deno task ( #35318 ) feat(task): input-based caching with files/output/env ( #34509 ) feat(task): set npm_execpath, npm_node_execpath and npm_command for package.json scripts ( #35317 ) feat(test): add --changed and --related flags to deno test ( #35199 ) feat(test): add --shard flag to split a test run across machines ( #35057 ) feat(test): add Deno.test.each for parameterized tests ( #34938 ) feat(test): add retry and repeats options to Deno.test ( #35053 ) feat(test): built-in snapshot testing via t.assertSnapshot ( #35139 ) feat(test): show sub-millisecond test durations ( #35200 ) feat(unstable): CSS module imports (with { type: "css" }) ( #35093 ) feat: deno desktop subcommand ( #33441 ) feat: deno remove --global as alias for deno uninstall --global ( #35327 ) feat: add "preferPackageJson" deno.json setting ( #35392 ) feat: add stable --unsafe-proto flag ( #34738 ) feat: enable default minimum dependency age ( #35458 ) feat: stabilize "links" field in deno.json ( #34996 ) feat: stabilize bare node built-in resolution ( #33316 ) feat: support ignore option in Deno.watchFs ( #31582 ) feat: support navigator.userAgentData ( #34743 ) fix(check): treat npm .d.ts as CJS based on package.json ( #35166 ) fix(core): always register isolate to prevent sil

Improvements and security content

• 2.9.0 / 2026.06.25 Read more: http://deno.com/blog/v2.9 feat(bundle): add --declaration flag to generate rolled-up .d.ts files ( #33838 ) feat(cli): add deno link and deno unlink subcommands ( #34359 ) feat(cli): add deno watch subcommand ( #35301 ) feat(cli): add deno list subcommand to list declared dependencies ( #34972 ) feat(cli): auto-migrate pnpm-workspace.yaml on resolution failure ( #34993 ) feat(cli): provide a node on PATH when Node.js is not installed ( #34969 ) feat(compile): persist Web Storage/KV in a per-app data directory ( #34618 ) feat(coverage): add configurable coverage thresholds ( #35056 ) feat(desktop): --compress for self-extracting app bundles ( #35420 ) feat(desktop): add Linux .deb and .rpm installer output formats ( #35296 ) feat(desktop): add Windows .msi installer output format ( #35378 ) feat(desktop): autodetect Vite framework ( #35470 ) feat(desktop): default UI backend to webview ( #35442 ) feat(ext/crypto): support remaining modern WebCrypto algorithms ( #35223 ) feat(ext/http): deprecation warning for legacy request abort ( #34397 ) feat(ext/net): implement Happy Eyeballs for Deno.connect and Deno.connectTls ( #31726 ) feat(ext/node): implement node:test mock.module ( #35329 ) feat(ext/node): implement node:test mock.timers ( #33946 ) feat(ext/web): web locks api ( #31166 ) feat(fmt): add sortNamedImports and sortNamedExports options ( #33313 ) feat(fmt): infer config from .editorconfig ( #34071 ) feat(fmt): use lax-css for CSS, SCSS, and Less ( #35160 ) feat(fmt): use lax-markup for HTML, XML, SVG, and components ( #35174 ) feat(fmt): use lax-sql for SQL formatting ( #35161 ) feat(http): allow disabling serve compression ( #35253 ) feat(http): disable Deno.serve automatic compression by default ( #35486 ) feat(install): create node_modules for workspace members ( #34970 ) feat(install): seed deno.lock from bun.lock ( #35394 ) feat(install): seed deno.lock from package-lock.json ( #35330 ) feat(install): seed deno.lock from pnpm-lock.yaml ( #35346 ) feat(install): seed deno.lock from yarn.lock ( #35350 ) feat(install): warn on package.json engines mismatch ( #34225 ) feat(lockfile): auto-resolve git merge conflicts in deno.lock ( #34726 ) feat(lsp): add inferred type request ( #35099 ) feat(napi): implement Node-API version 10 ( #35270 ) feat(node): bump reported process.version to v26.3.0 ( #34747 ) feat(npm): install jsr deps into node_modules via npm-compat registry ( #35029 ) feat(npm): publishing-trust ranking and no-downgrade trust policy ( #34927 ) feat(runtime): add request_builder_hook for fetch token and cdn-loop headers ( #35088 ) feat(task): add --if-present flag to deno task ( #35315 ) feat(task): add --jobs/--concurrency flag to deno task ( #35318 ) feat(task): input-based caching with files/output/env ( #34509 ) feat(task): set npm_execpath, npm_node_execpath and npm_command for package.json scripts ( #35317 ) feat(test): add --changed and --related flags to deno test ( #35199 ) feat(test): add --shard flag to split a test run across machines ( #35057 ) feat(test): add Deno.test.each for parameterized tests ( #34938 ) feat(test): add retry and repeats options to Deno.test ( #35053 ) feat(test): built-in snapshot testing via t.assertSnapshot ( #35139 ) feat(test): show sub-millisecond test durations ( #35200 ) feat(unstable): CSS module imports (with { type: "css" }) ( #35093 ) feat: deno desktop subcommand ( #33441 ) feat: deno remove --global as alias for deno uninstall --global ( #35327 ) feat: add "preferPackageJson" deno.json setting ( #35392 ) feat: add stable --unsafe-proto flag ( #34738 ) feat: enable default minimum dependency age ( #35458 ) feat: stabilize "links" field in deno.json ( #34996 ) feat: stabilize bare node built-in resolution ( #33316 ) feat: support ignore option in Deno.watchFs ( #31582 ) feat: support navigator.userAgentData ( #34743 ) fix(check): treat npm .d.ts as CJS based on package.json ( #35166 ) fix(core): always register isolate to prevent sil

Affected products and versions

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Official publisher evidence