computeCurrentScript() from d8 preamble fails in VS Code extension host (NodeJS) due to tabs instead of spaces for stack trace indenting

[DanTup]

I was trying to run some compiled Dart in a VS Code extension (which runs in a NodeJS process) using the d8 preamable file).

The computeCurrentScript function fails like this:

I added some logging of the regex and the stack that was captured:

      var lastMatch = null;
      do {
        console.warn(re.source);
        console.warn(stack);
        var match = re.exec(stack);
        console.warn(match);
        if (match != null) lastMatch = match;
      } while (match != null);
      return lastMatch[1];

And the output looked like this:

Everything appeared good but after some more debugging I found that the stack trace here has tabs and not spaces!

If I change the start of the regex from /^ *at to /^\s*at then the code works (or at least it gets further.. but I think the remaining issues are my own).

I cannot figure out why the stack traces have tabs here, but it seems like changing the space to \s here would not be breaking so I'm hopeful that it is a change that could be made. I'm happy to open a CL if someone can confirm this is a valid change.

[sigmundch]

Wow, that's so bizarre!

I'm not opposed to changing it just to make it more flexible. Here is a CL to do so: https://dart-review.googlesource.com/c/sdk/+/366160

Note: while the d8 preamble is OK to use in node, the node_preamble may be a better fit. That package however has the same logic and currently uses spaces rather than \s, so it would also need to be updated.

[DanTup]

Here is a CL to do so: https://dart-review.googlesource.com/c/sdk/+/366160

Thanks!

Note: while the d8 preamble is OK to use in node, the node_preamble may be a better fit.

It actually turned out that the preamble completely broke all the built-in VS Code extensions. It seems like it was manipulating something global that VS Code / other extensions didn't expect that I got lots of exceptions. In the end I ditched the pre-amble and just added the minimum I needed (I think globalThis.self = globalThis.self ?? {};) for the code to run.

I don't know what the d8 in that preamble meant, I just saw someone else link to it and tried it. I'm curious what it's intended for / how it differs from the node_preamble package?

If I did need one though, I'd be concerned about depending on a package that just says "unverified uploader" and hasn't been published for 14 months - I assumed what's in the SDK would be more likely to be maintained (but that feeling is probably not based on a whole lot!).