Compile and bundle the MQTTX-CLI code using BunJS.

[ni00]

I am considering whether BunJS can be used to compile and bundle MQTTX-CLI, which might bring the following advantages:

1. Smaller bundle size, expected to reduce by 20%-50%;
2. Faster compilation and packaging speed, potentially improving by 2-10 times;
   
3. Better runtime performance, as multiple benchmark tests have shown that BunJS indeed exhibits faster execution speed;
4. Lower migration cost, as BunJS is highly compatible with existing Node.js projects.

However, this approach might also have some potential issues:

1. Higher memory requirements, as some feedback suggests that JSCore might consume more memory than V8, though this is not yet certain.
2. BunJS's bundler is still in beta, which might have unknown bugs, and it currently does not support the win-arm64 architecture.
   

So I will do some testing in my spare time, @ysfscream @Red-Asuka , what do you think about the feasibility and value of this idea? Or should we wait until v2 to do the testing?

Reference link: https://bun.sh/docs/bundler/executables

[ysfscream]

@ni00, it makes sense, and thanks for your purpose. Actually, I’ve already tried using Bun.js to compile the MQTT CLI — it’s really fast and lightweight. But as you mentioned, Bun.js also brings a lot of uncertainties. Although it’s evolving rapidly, there are still risks. Node.js is a very stable one.

I’ve also been considering trying Zig or Golang to build the CLI for better performance, but that doesn’t align well with our current JS tech stack.

So my suggestion is that we could release a mqttx-cli-lite version to experiment with some of these optimizations. If you think Bun.js is good for that, feel free to start development under the https://github.com/emqx/MQTTX/tree/dev/2.0.0 2.0 branch by adding a new package. Maybe we can pre-release this 2.0 Lite CLI tool if it works well. Thanks.

Related issue: #1740

[Red-Asuka]

@ni00 Thank you for your suggestions! Here's our technical plan regarding the packaging strategy:

Current Approach
The V1 release will continue using the pkg solution to maintain stability, with no immediate changes planned.
V2 Technical Evolution
We're adopting Node.js 21+ Single Executable Applications for CLI packaging, as it's officially maintained and deeply integrated with Node.js.
Considerations on Bun
We acknowledge Bun's advantages in lightweight packaging and performance
Key evaluation points:
▪︎ Feasibility of adopting a separate packaging solution specifically for the CLI module within our existing turbo+pnpm monorepo architecture
▪︎ Compatibility with current toolchain (cross-platform builds, dependency management, etc.)
We encourage you to submit Bun packaging implementation examples against the V2 PoC branch, which would significantly aid our decision-making process!
Looking forward to further technical discussions! 🚀