Experiment: AsyncPromise, a Promise that captures 1 stack frame

[Jarred-Sumner]

What does this PR do?

Stack traces for async functions are often missing

This adds an internal Promise wrapper for async native functions which captures 1 stack frame and propagates it on promise rejection.

After:

 9 | }
10 |
11 | async function hey() {
12 |   await 42;
13 |
14 |   readFile("fd-3.mjs").catch((e) => {
       ^
ENOENT: No such file or directory
   errno: -2
 syscall: "open"
   path: "fd-3.mjs"

      at fd-2.mjs:14:3

Before:

ENOENT: No such file or directory
   errno: -2
 syscall: "open"
   path: "fd-3.mjs"

Worth reading what v8 does

I don't think this PR's approach is quite right. This is only 1 stack frame, and only when using this special AsyncPromise in Zig/C++. It doesn't chain.

I think it'd be better to reuse the extra context argument in the await-specific code to have a reference to the StackFrame (though ideally without creating an additional JSCell)

cc @dcrousso incase you find this interesting

I did a little benchmarking and couldn't find a measurable performance impact to this

How did you verify your code works?

[github-actions]

❌ @Jarred-Sumner, your commit has failing tests :(

💪 1 failing tests Darwin AARCH64

• test/js/bun/test/stack.test.ts 1 failing

💻 2 failing tests Darwin x64 baseline

• test/js/bun/test/stack.test.ts 1 failing
• test/js/web/workers/worker.test.ts 1 failing

💻 1 failing tests Darwin x64

• test/js/bun/test/stack.test.ts 1 failing

🐧💪 1 failing tests Linux AARCH64

• test/js/bun/test/stack.test.ts 1 failing

🐧🖥 2 failing tests Linux x64 baseline

• test/js/bun/test/stack.test.ts 1 failing
• test/regression/issue/09041.test.ts 1 failing

🐧🖥 1 failing tests Linux x64

• test/js/bun/test/stack.test.ts 1 failing

🪟💻 2 failing tests Windows x64 baseline

• test/integration/next-pages/test/dev-server.test.ts 1 failing
• test/js/bun/test/stack.test.ts 1 failing

View logs

[dcrousso]

support for capturing and linking stack traces across async boundaries was added to Web Inspector in 252543@main by instrumenting queueMicrotask (and JSMicrotask::run). perhaps yall could use/duplicate that logic?