Error.stack does not use source map

[mitsuhiko]

What version of Bun is running?

0.5.9

What platform is your computer?

Darwin 22.4.0 arm64 arm

What steps can reproduce the bug?

I was trying to figure out reported column offsets in bun (see tc39/source-map#5 (comment)). For some reason I get wrong line numbers and columns. Reported:

function fail() {
  throw new Error();
}

function logColumn(c, e) {
  const lines = e.stack.split(/\r?\n/g);
  if (lines[0] === 'Error') {
    lines.shift();
  }
  console.log(c, parseInt(lines[1].match(/:\d+:(\d+)/)[1]));
}

try {
  /* xxxxx */fail();
} catch (e) {
  logColumn("x", e);
}
try {
  /* ☃️☃️☃️☃️☃️ */fail();
} catch (e) {
  logColumn("☃️", e);
}
try {
  /* 🔥🔥🔥🔥🔥 */fail();
} catch (e) {
  logColumn("🔥", e);
}
try {
  /* 👩‍👩‍👧👩‍👩‍👧👩‍👩‍👧👩‍👩‍👧👩‍👩‍👧 */fail();
} catch (e) {
  logColumn("👩‍👩‍👧", e);
}

What is the expected behavior?

Expected

x 14
☃️ 19
🔥 19
👩‍👩‍👧 49

What do you see instead?

x 7
☃️ 7
🔥 7
👩‍👩‍👧 7

Additional information

If you add some print on the lines you can see that not just the columns are wrong, the lines are too.

[Jarred-Sumner]

Source maps are not yet integrated into Error.prototype.stack - what you're seeing is the stack from the transpiled source in JavaScriptCore

You can use Error.captureStackTrace or console.error to get a source-mapped error