`@swc/wasm-typescript` error snippet not working

[marco-ippolito]

Refs: https://github.com/nodejs/amaro/pull/202/files

for example the syntax const foo;.
throws this error:

{
  "code": "InvalidSyntax",
  "message": "'const' declarations must be initialized",
  "snippet": "foo",
  "filename": "<anon>",
  "line": 1,
  "column": 6
}

Note that snippet foo does not give enough info.
The snippet should be:

const foo; and have startColumn and endColumn so we can mark the syntax thats incorrect, or
directly something like:

const foo;
      ^^^

I know you are already aware of it, creating this issue to track.
Thanks for your work <3

[kdy1]

Marking as GFI because we only need to fix the span.

[marco-ippolito]

I gave it a try but was not able to figure out what to change. I assume we should iterate over d.span.span_labels() ?

[kdy1]

No, we should change the span of the parser error.

[kdy1]

Note that the span should only point to foo in the const foo case to be consistent.
For example, you can think of const a = 1, b, which is also a possible error case.

I can add a subdiagnostic that points to const, but changing the span itself is not a good idea IMHO.

[marco-ippolito]

Afaik it requires a fix in the parser to get the correct span? I remember before throwing the error as an object the snippet was working fine. What has changed?
When I throw an error in Node I need the snippet to report the code that throw that error.
foo is probably not enough. I would need a piece of the code.
In the past the snipped that was inside

_______
|
| const foo;
|       ^^^
|
---------

Contained the right information.
Basically

const foo;
      ^^^

is all I need.

[marco-ippolito]

I think the PR still does not fix the issue that the snippet does not contain all the code needed to show to user.
startColumn and endColumn and endLine are needed only if the snippet does not contain the ^^^^