WIP: get better frame info from prepareStackTrace

[kevinkassimo]

This is a hacked-up demo of how to leverage prepareStackTrace to get better error messages. Currently there are errors if you try throwing non-error or call eval that errors, but those are problems that could be addressed easily after validating this demo.

Example:

await Deno.open("./BOOM");

Before (deno 0.35.0, thus there are a few more frames than master):

error: Uncaught NotFound: No such file or directory (os error 2)
► $deno$/errors.ts:37:13
    at NotFound ($deno$/errors.ts:75:5)
    at constructError ($deno$/errors.ts:37:13)
    at unwrapResponse ($deno$/dispatch_json.ts:41:12)
    at sendAsync ($deno$/dispatch_json.ts:96:10)

After:

error: Uncaught NotFound: No such file or directory (os error 2)
    at unwrapResponse ($deno$/dispatch_json.ts:42:12)
    at sendAsync ($deno$/dispatch_json.ts:97:11)
    at async open ($deno$/files.ts:94:16)
    at async file:///Users/kun/Projects/Deno/test/tla.ts:1:1

[nayeemrmn]

Maybe just assign the whole array above/below?

[kevinkassimo]

I can definitely do that, but actually I was thinking about not saving callSite but an object populated with data we need (since currently I am actually calling a bunch of function from Rust)

[piscisaureus]

I agree with @kevinkassimo on this one.

[piscisaureus]

I would also consider implementing the entire prepareStackTrace function in C++.

Not 100% sure, but it might be nice to keep the part where the call sites get stored and where they get processed close together.

That is something that I can do if you don't want to btw.

[kevinkassimo]

@piscisaureus Yeah I think that is reasonable. I don't think I will have enough time to work on it this week (finals are coming), so yeah for sure

[nayeemrmn]

Getting a +1 offset for column/row numbers.

deno/core/js_errors.rs

Lines 217 to 218 in 93aed08

	let line_number = line_number + 1;
	let column = column + 1;

adjusts for the 0-based numbers that the old API gives?

[kevinkassimo]

Getting a +1 offset for column/row numbers.

deno/core/js_errors.rs

Lines 217 to 218 in 93aed08

	let line_number = line_number + 1;
	let column = column + 1;

adjusts for the 0-based numbers that the old API gives?

Ooops forgot to add 1, but yeah it is a small problem that could be fixed easily.