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New Biome, Mocha, Jest, and k6 Releases All Kissed by TypeScript | News | Ep 23

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Jun 24, 2025

Discover the latest advancements in TypeScript with features like Biome v2's type-aware linting. Mocha and Jest have both upgraded to support native ESM and TypeScript. Explore Grafana's k6 now offering TypeScript testing. Learn about exciting community contributions focused on type safety and better import maps. Dive into the challenges and joys of outdoor adventures paired with discussions about balancing work and personal projects. Plus, uncover the utility of `promise.try` for efficient function management!

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INSIGHT

TypeScript Iterator Naming Solution

TypeScript solved a global iterator name clash by introducing a new iterator object type without breaking existing code.
When designing types, anticipate conflicts by prefixing to avoid clashes with evolving ECMAScript features.

INSIGHT

Import Maps Improved for Modular Browsers

Import maps help browsers resolve module specifiers, decoupling import names from file paths.
Shopify engineering improved import maps to allow multiple maps and better support micro-frontends.

INSIGHT

Vite Plus Targets Enterprise Control

Void Zero plans a premium Vite Plus for enterprises adding control, audits, and GUI tools while keeping core open source.
Charging for more control rather than features appeals to enterprise users for policy enforcement and workspace management.

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News for the week of June 16, 2025: Biome v2 features type-aware linting without TSC, Mocha and Jest both get native ESM and TS upgrades, and Grafana Lab's k6 load testing tool... also can now run native TS tests. From the community: type safety for WebGPU shaders, type narrowing map and indexed key access, and resilient import maps.

Chapters

(00:00) - Introduction and Personal News
(05:02) - News: Biome v2 Features Type-aware Linting Without TSC
(08:25) - News: Mocha 11.7.0 Adds Support for Native ESM and TypeScript
(09:35) - News: Jest 30 Also Adds Native ESM and TypeScript Support
(11:12) - News: Grafana k6 Celebrates 1.0 Release with TS Support
(13:30) - News: WebGPU is (Finally) Coming to All Major Browsers
(14:36) - News: Astro 5.9 Adds Support for Content Security Policy
(15:47) - PSA: Deno's Homebrew Release is Behind Other Versions
(16:34) - Community Highlight: Bridging ESM and CommonJS by Joyee Cheung
(18:16) - Community Highlight: How Queues Work in TypeScript
(19:00) - Community Highlight: Dr. Axel's Corner
(21:11) - Community Highlight: Better Import Maps from Shopify Engineering
(24:32) - Community Highlight: VoidZero Discusses Vite+ Plans
(28:22) - Community Highlight: TypeScript Native Port Speeds Up Slack's CI Builds
(29:09) - Community Highlight: TypeGPU Lets You Write WGPU Code in a Type-safe Way
(33:21) - Community Highlight: Remembering Mikael Rogers
(35:08) - Cool API: Promise.try
(36:52) - Cool Read: The Dying Art We All Depend On by Raptitude
(38:16) - Cool Watch: The Story of Rollup with Rich Harris

News

Biome v2 codename Biotype brings type-aware linting without TSC!
- You can check out what the noFloatingPromises rule looks like to write type-aware rules
Mocha 11.7.0 is now compatible with Node’s require(ESM) & type stripping (h/t Rob Palmer)
After 3 years, Jest 30 is a massive release which includes native ESM and TS support
- Fun fact: Christoph Nakazawa open sourced his game: https://github.com/nkzw-tech/athena-crisis
Grafana k6 celebrates a 1.0 release with native support for TypeScript tests
Firefox will unflag WebGPU in v141 (Firefox Release Calendar), bringing WGPU support to all major browsers for iOS, Windows, and macOS in the next year or so.
Astro 5.9 brings Content Security Policy (CSP) support for more secure web app development
PSA: Deno Homebrew version is behind because of a bug in Rust

From the Community

Joyee Cheung (Node TSC) talk on Bridging CommonJS and ESM in Node.js
freeCodeCamp Blog: How Queues Work in TypeScript by Yazdun
Dr. Axel's Corner:
- How TypeScript solved its global `Iterator` name clash
- TypeScript: checking Map keys and Array indices
Resilient Import Maps - Better Theme Development and Beyond (2025) - Shopify
Vite’s Creator on a Unified JavaScript Toolchain and Vite+ - The New Stack
@slack.engineering on Bluesky shares CI improvements by migrating to TSGO
TypeGPU 0.5.9 release by Iwo Plaza
- Video: Iwo Plaza – The Road to Type-Safety on the GPU | RNCK #15
- Video: Erik's Stream: Learning WebGPU Together

In Memoriam: Mikeal Rogers

Via Node.js foundation:

We’re heartbroken by the loss of Mikeal Rogers, a key figure in the Node.js ecosystem and a force behind what makes this community what it is. To help preserve his legacy, we’ve opened a GitHub repo for stories, photos, and memories: github.com/nodejs/mikeal

💚 Thank you, Mikeal.

Via Linux Foundation: In Memory of Mikeal Rogers: A Builder of Communities

Cool Stuff

Promise.try - wrap a function in a promise or execute immediately, avoiding a microtask when not needed
The Dying Art We All Depend On by David from Raptitude
The Story of Rollup with Rich Harris (via Matt Jennings)

Sponsored by Excalibur.js
Excalibur.js is the friendly TypeScript game engine for making 2D web games. Use your TypeScript or JavaScript skills to make games! Excalibur comes out-of-the-box with everything you need to make web games, like physics, sprites, animations, sound effects, input, and particles. Design your assets with tools like Aseprite and Tiled, then load them natively using first-party plugins.

Music
Seahorse Dreams by Kubbi (Spotify)