ast node span is incorrect when leading comments existed

[huozhi]

Describe the bug

When there's comment at the beginning, the first span of AST node is always starting with 0, instead of actual position of first non-comment code position in the original code

Input code

/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

'use strict';

Config

No response

Playground link

https://play.swc.rs/?version=1.3.74&code=H4sIAAAAAAAAA0WOyw6CQAxF93zF3aEExcfSJcGERN3ID2inyEQyJZ1hwd87k2hc9vTe01ZFkaFALdOi9jUErGiNw25%2F3EzKnl0ocX4QP0XeJVpH25hOhW6wHl5mJQaJYcRxtMTOs8HsDCvCwLi23Q%2Bjl8hhXVokxaWtm9u9QW9H%2FmKoSICxyhREF0gf6f9QUOb0QJVl%2BRyNPqilkJ%2ByDz%2Bh%2BQvGAAAA&config=H4sIAAAAAAAAA2VRsY7DMAjd%2BxURc4dTxttu7NCPsHykci82FhCpUZV%2FL6RJmugWC97j8QA%2FT00Dd4nw3TwttKQGFuQtN0TGouFhCOhYUSKnqnBeWRWnlAeckelNgAa%2BoboIpf1q20UAPZGgwV3oBddaDkU64rx3ZQxRd4BDQ9GUXQ1hUMpBU4SFng7uOZXUjft2kXJlFDlae2kot36b6NAFHxXZDG39ft%2FrD7FeciXWH7FbaaIi%2F24wP59BNlNIcqXfYbZ0xbtsRZZP8EP7mjZ1pnIX33I6TS9UUQp0rgEAAA%3D%3D

Expected behavior

for 1st non comment code "use strict" directive, the output AST is showing span from 0. It should be the position of that string literal from original code.

{
  "type": "Module",
  "span": {
    "start": 0,
    "end": 13,
    "ctxt": 0
  },
  "body": [
    {
      "type": "ExpressionStatement",
      "span": {
        "start": 0,
        "end": 13,
        "ctxt": 0
      },
      "expression": {
        "type": "StringLiteral",
        "span": {
          "start": 0,
          "end": 12,
          "ctxt": 0
        },
        "value": "use strict",
        "raw": "'use strict'"
      }
    }
  ],
  "interpreter": null
}

Actual behavior

No response

Version

1.3.74

Additional context

We're using span to get the position of the code, and delete them from the original code. For instance, A rollup plugin is checking "use client" directives and trying to delete it from the original code.

x-ref: huozhi/rollup-preserve-directives#9

[kdy1]

Actually lo and hi is BytePos so it's expected. There's no good way to use source location from JS plugin, and JS plugin is going to be deprecated anyway.

[huozhi]

Gotcha, sounds like modifying the source based on the spam position could be very risky.

[magic-akari]

But the node span works well in the rust side.
check it: swc ast viewer

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.