r/javascript 10h ago

AskJS [AskJS] what's a javascript feature you mass-adopted way too late and felt dumb about

26 Upvotes

i'll go first. i was writing .then().catch() chains for like two years before i actually started using async/await. i knew it existed, i'd seen it in tutorials, but my code "worked" so i never bothered switching. then i refactored an old project and realized half my bugs were from mishandled promise chains that async/await would have caught immediately.

also took me way too long to start using optional chaining. i had nested ternaries and && checks everywhere like some kind of animal. the day i discovered user?.address?.city i mass-replaced like 40 lines across a project.

what's yours?


r/javascript 9h ago

color-space v3: 162 color spaces, one small API, values that match CSS, verified

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16 Upvotes

r/javascript 1h ago

create-creact-app: Now its easier than ever to spin up your new CReact application!

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โ€ข Upvotes

This is not about UI, read more if you are into DAGs, Declarative Programming, or if you just like to do things differently


r/javascript 8h ago

Angular is moving to a yearly major version release cycle

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4 Upvotes

r/javascript 9h ago

Travels 2.1 - Efficient framework-agnostic undo/redo library based on JSON patches rather than snapshots.

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3 Upvotes

r/javascript 9h ago

[Showoff] Blue Checkmark Coding Agents, Simulated DoorDash Orders, and a Cyberpunk Wizard of Oz

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0 Upvotes

Hey Community,

We explore Grok Build, the new terminal-based TUI coding agent from x.ai. We also look at Appless, an experiment from the creators of OpenUI that bypasses chat bubbles to stream live native UI components using openui-lang.

Finally, we dive into Maestro MCP, a new tool context protocol server that lets AI agents automatically build and run YAML test flows from plain English instructions.

If the Rewind made you nod, smile, or think "ohโ€ฆ that's actually cool" โ€” a share or reply genuinely helps โค๏ธ


r/javascript 5h ago

Built a modern restaurant website with React, TypeScript & Vite โ€” feedback welcome

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0 Upvotes

r/javascript 1d ago

I cut my build time from 4:34 min to 1:08 min by moving asset compression from node:zlib to a native Rust rolldown plugin

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5 Upvotes

I'm building a web platform for visual novels made in Godot. Stack: SvelteKit, Vite 8, rolldown, Node.js.

The games are compiled for web and injected as static assets at build time, then deployed together with the app. And they're heavy: ~20 MB of wasm plus ~150 MB of pck per game.

My builds were taking ~5 minutes, which felt wrong. After some profiling it turned out the actual bundling takes ~10 seconds. Everything else was precompressing all that static into gz, br and zstd with node:zlib.

So I wrote a rolldown plugin that does the compression in native Rust via napi-rs:

  • rayon to saturate all CPU cores
  • native compression libs instead of node:zlib bindings
  • full LTO + codegen-units = 1, which alone made it ~2x faster than node:zlib
  • then PGO + BOLT on top, squeezing out another ~10%

Everything is built automatically in a GitHub workflow and shipped to npm already optimized, no compilation on install.

Real project resultsย (measured withย timeย on an actual project with games):

before: npm run build 639.62s user 5.84s system 235% cpu 4:34.06 total
after: npm run build 527.60s user 5.23s system 784% cpu 1:07.95 total

If you're precompressing large static assets in your build, give it a try. Happy to answer questions about the napi/rayon/PGO setup.


r/javascript 14h ago

July 2026 Security Release

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0 Upvotes

r/javascript 1d ago

Modyra 0.3.0 is here

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0 Upvotes

r/javascript 1d ago

Your JS Date Is Lying to You: parsing ambiguity, silent mutation, timezone traps, and how Temporal fixes most of them

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0 Upvotes

Covering the main waysย Dateย misleads you in production: parsing, mutation, 0-based months, timezone/DST, arithmetic, and serialization, with safe patterns for code that can't migrate yet, and a practical look at whereย Temporalย fixes the design rather than just the syntax.


r/javascript 2d ago

The TypeScript patterns that made the biggest difference after moving from JavaScript

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33 Upvotes

I've been using TypeScript professionally for several years, and recently wrote up some lessons learned from a long-running React/Firebase side project.

The article covers the TypeScript patterns that ended up giving me the biggest return, along with a few mistakes I'd avoid making again. These aren't intended as universal rules, just approaches that worked well for this particular project and the problems I was solving.

If you're a JavaScript developer who's moved to TypeScript (or is considering it), I'd be interested to hear which patterns have been most valuable for you as well.


r/javascript 1d ago

I made zero-allocation FAST s3-fifo cache package(would love to get feedback!)

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2 Upvotes

Recently, I noticed there is no proper s3-fifo implementation in NPM.

s3-fifo is highly efficient cache algorithm, especially for "one-hit-wonders" case such as web traffics. It is specialized when cache coverage is under 50%. (like, whole DB is 100% and cache contains 50% of data)

The famous "lru-cache" package is almost default for nodejs ecosystem I think, and I thought it would be great if there is good alternative choice for caching.

My goal was:

1. Faster or at least same throughput performance compared to lru-cache

2. Much higher cache hit rate than lru-cache

bold, right?

It was fun enough just for challenge itself.

But it was actually achieved! I used bunch of optimization skills like pre-allocation, lazy eviction, bitwise tricks, ring structure and etc... you can see bench result in repo or NPM page.

It is just v0.1 for now, so I would LOVE to get your harsh feedback, advice, or even contribution!

NPM page

Super thanks for reading!

----

I typed almost of the code by my hand. Not because I don't believe AI, but it was all about concepts and decisions. Typing by hand was fastest way to understand what I'm doing correctly. And it was fun.

I used AI(gemini) for test codes, some advices and polishing when most of things were done.


r/javascript 2d ago

GitHub - sysmaya/Javascript-Image-Background-Remover: I promise not to write any more stupid things.

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0 Upvotes

r/javascript 2d ago

Subreddit Stats Your /r/javascript recap for the week of July 13 - July 19, 2026

1 Upvotes

Monday, July 13 - Sunday, July 19, 2026

Top Posts

score comments title & link
64 14 comments Firefox in WebAssembly!
59 48 comments I stopped destructuring everything
30 9 comments The LinkedIn scam that gets you hacked - Solving a take-home interview test can quickly turn into a nightmare. Notes on developer trust, JavaScript malware, and autonomous detection
29 5 comments I built an Excel library
22 3 comments PSA: The official jscrambler npm package was compromised (v8.14.0)
13 9 comments The same app built in 10 different frontend frameworks. For automated performance benchmarking
12 5 comments Pitter Patter โ€” building better editing (update!)
11 1 comments Collection of clocks made with JS
9 39 comments JavaScript Magic Objects
7 0 comments Vue 3.6 just entered RC stage

 

Most Commented Posts

score comments title & link
0 24 comments [AskJS] [AskJS] From Node Js to Java spring?????? 4.8 yrs EXP
0 22 comments I coded a 60fps browser game from scratch in single-file Vanilla JS, mapping Upanishadic philosophy to state variables. No frameworks.
0 14 comments PDF engine from scratch on JS
0 13 comments RestQL โ€“ GraphQL-like queries over REST, purely client-side: schema-driven mapping, batching, request dedup, caching
0 8 comments I created a zero dependency JavaScript framework that is a React alternative

 

Top Ask JS

score comments title & link
0 3 comments [AskJS] [AskJS] every github repo already exposes releases.atom, tags.atom, and commits.atom, so keeping up is a summarization problem not a feed problem

 

Top Showoffs

score comment
2 /u/grelfdotnet said Caves procedurally generated as you explore them. Real time, 3D, limitless. A different kind of environment that might be useful for games. My idea is that it makes for more varied spaces than the ...
1 /u/Valuable_Apple2581 said Additive model regression in a vanilla JS, one linear solve, no build step and works from file:// Well, a while ago I came across a 1992 statistic paper which described a way to fit an additive regre...
1 /u/Flashy-Guava9952 said [https://github.com/illogical-alliteration/notebook/](https://github.com/illogical-alliteration/notebook/) is a Jupyter-like notebook for Javascript, Typescript, and Markdown. It saves...

 

Top Comments

score comment
61 /u/rlmineing_dead said hey dawg I heard you like browsers so I put a browser in your browser so you can browse while you browse
51 /u/azhder said Destructuring isnโ€™t only about you knowing where a value comes from. You can also safeguard in a cleaner manner i.e with less syntax noise: const { id: userId, name: userName } = user ?? {}; console...
41 /u/smartgenius1 said Magic methods are generally discouraged in the PHP community, and are widely considered a bad decision. Why port them to JS?
40 /u/jCuber said I still prefer to destructure the first level of `props` in React as it raises linter findings for unused props for removal.
36 /u/javascript said Proxy Objects (getters and setters) have been around for a while but I've yet to come across a use case where they were the right choice. They tend to work more as an escape hatch.

 


r/javascript 3d ago

Vue 3.6 just entered RC stage

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8 Upvotes

r/javascript 2d ago

Your Recursion Is Lying to You

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0 Upvotes

r/javascript 2d ago

I built a browser-only video auto-editor using optical flow and Chromeโ€™s built-in AI

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0 Upvotes

r/javascript 3d ago

Made a Vector heavily inspired by C++'s std::vector, not like a stub or a gimmick.

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1 Upvotes

Though it requires quite new ES2024/ES2025 features, it works very well for numeric types, also faster (not drastically, but modest gains) against Array in PACKED FIXED ELEMENT TYPES representation used under the hood by engines.


r/javascript 3d ago

GitHub - ArcadeMode/unplugin-dotnet-wasm: Seamless bundling of .NET Browser apps (WASM) into your JS projects

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0 Upvotes

.NET WebAssembly apps with WasmBundlerFriendlyBootConfig=true can indeed be bundled by modern JS bundlers and I personally love it. The development experience however is not optimal.

  • The bundlers cannot consume the output from dotnet build
  • The bundlers can consume the output from dotnet publish but the dev loop is painfully slow.
  • Getting the publish path working still requires bundler surgery
  • Once it works the bundler produces warnings that are impossible to fix without changing the source files produced by the WebAssembly SDK.

These points of friction are why I have made unplugin-dotnet-wasm.

It's a bundler plugin that lets your bundler consume the output from dotnet build so your dev loop stays fast. It also supports dev servers, provides type information to TypeScript and IDEs (integrates dotnet.d.ts thats coming in .NET 11), and patches the known warnings so your build output stays clean.

Features

  • Easy bundler setup through plugin registration
  • Faster dev loop by consuming .NET WebAssembly dotnet build output
  • Dev server support
  • Brings SDK type definitions to TypeScript and your IDE
  • Supports Vite, Rollup, Rolldown, Webpack, Rspack, Rsbuild, esbuild, farm and bun.

I hope you'll give it a try, I'd be happy to hear your feedback.


r/javascript 3d ago

GitHub - sysmaya/AI-Image-Colorizer: Colorize old photos instantly with AI. 100% JavaScript, ONNX running in the browser

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0 Upvotes

r/javascript 3d ago

LIA - Open Source - Personal Assistant - Self hostable on Raspberry Pi 5

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0 Upvotes

This is a free/non profit unapologetically claude code vibe-coded project; the approach is explained here:ย https://lia.jeyswork.com/story

If you like it, please don't hesitate to show your support with a star on GitHub!

LIA acts as a true personal assistant. It is proactive, featuring its own distinct personality and a complex emotional system, an evolving structured memory, its own reflective memory of your conversations, and all the standard tools (image creation/editing, RAG, skills, MCP, scheduled tasks, etc.)โ€”all wrapped in a seamless "one-click" interface (details here:ย https://lia.jeyswork.com/why).

I paid special attention to code quality and documentation, treating it exactly like a professional enterprise-grade project. This ensures that anyone can easily take ownership of the source code and build upon a clean, robust, and highly scalable foundation (details here:ย https://lia.jeyswork.com/how).

On another note, once self-hosted, it can double as a family AI server. As an administrator, you have full control to manage and monitor the API consumption of your family members, friends, etc.

Full details are available on the landing page:ย https://lia.jeyswork.com/

And the GitHub repository:ย https://github.com/jgouviergmail/LIA-Assistant


r/javascript 3d ago

RestQL โ€“ GraphQL-like queries over REST, purely client-side: schema-driven mapping, batching, request dedup, caching

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0 Upvotes

r/javascript 4d ago

Typed and validate config for decoupled codebases in any JS runtime

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0 Upvotes

r/javascript 4d ago

Showoff Saturday Showoff Saturday (July 18, 2026)

2 Upvotes

Did you find or create something cool this week in javascript?

Show us here!