Better ownership lint to kill ownership chaos for AI generated code

[loynoir]

🔍 Search Terms

• proposal-explicit-resource-management
• ownership
• lifetime

✅ Viability Checklist

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

Better ownership lint to kill ownership chaos.

Maybe rust lifetime?

📃 Motivating Example

See

denoland/deno#34953

Typescript should lint below code will crash due to ownership

Deno.serve({}, async (_req) => {
  using file = await Deno.open(new URL(import.meta.url).pathname);
  return new Response(file.readable);
});

denoland/deno#34953 (comment)

Some think

file.readable carries ownership of the file

denoland/deno#34953 (comment)

Some think file.readable does not carries ownership of the file

> file.readable[Symbol.dispose]
undefined

💻 Use Cases

1. What do you want to use this for?

Better ownership type

2. What shortcomings exist with current approaches?

TBD

3. What workarounds are you using in the meantime?

No way.

related

denoland/deno#34931

Simple code leads to server crash due to ownership

Genered by AI.

Simplified for reproduce.

Deno.serve({}, async (_req) => {
  using file = await Deno.open(new URL(import.meta.url).pathname);
  return new Response(file.readable);
});

---

denoland/deno#34953

How to easy stream file within deno server?

---

tc39/proposal-explicit-resource-management#274

How does proposal-explicit-resource-management suggest how to easy extend stream file lifetime within server?

---

#63540

Better ownership lint to kill ownership chaos

[MartinJohns]

Sounds like a duplicate of #16148. And no idea what the reference to AI is there for.

[loynoir]

Given AI generated below code equivalent.

Simplifed to reproduce.

Deno.serve({}, async (_req) => {
  using file = await Deno.open(new URL(import.meta.url).pathname);
  return new Response(file.readable);
});

Above code will crash server due to multiple reasons.

Prefer linter error over runtime crash.

But there gap that no way to lint.

1. using file and file.readable should not be used together

file.readable does not trigger file.close.

But when file.readable done, it trigger file.close.

Plus using leads to double free.

To extend life time, should use below.

  const file = await Deno.open(new URL(import.meta.url).pathname);
  return new Response(file.readable);

But, currently, no linter error.

Hard to audit AI generated life time code leads to server crash

BTW, I feature request tc39 adopt more readable naming convention

  const file = await Deno.open(new URL(import.meta.url).pathname);
  return new Response(file.into_readable());

2. I think proposal-explicit-resource-management and typescript lack of something like extend life time

  using file = await Deno.open(new URL(import.meta.url).pathname);
  return new Response(move file.as_readable());

[MartinJohns]

This has absolutely nothing to do with AI. Same code can be written by humans. Better Code can be written by AI.

[loynoir]

Yes, better code can be written by AI.

But AI may also sometimes combine using and file.readable leads to double free.

The Rust compiler can keep many problems at bay.

Would be nice to have stricter type system like rust.