fix: update sourcemap in importAnalysisBuild

[sapphi-red]

Description

importAnalysisBuild was breaking sourcemaps when there is a dynamic import.

This is a reproduction.
https://stackblitz.com/edit/vitejs-vite-ipkqha?file=main.js&terminal=dev

import './style.css';

console.log('1');
import('./dy');
console.log('2');
/* omit below */

• Current v2.9.5.
  
• With this PR (The output 2 has changed from line 4 to 5)
  

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

Could we create this MagicString at the top so we only use one, and only need to combine the source maps once?

[sapphi-red]

It needs to replace markers which were not replaced. Using the same MagicString instance was doing a different behavior here.

import MagicString from 'magic-string';

const mark = '__VITE_PRELOAD__';

const code = `
  import('foo.js', "__VITE_PRELOAD__")
  "__VITE_PRELOAD__"
`;

const s = new MagicString(code);

s.overwrite(
  code.indexOf(mark) - 1,
  code.indexOf(mark) + mark.length + 1,
  '["deps.js"]',
  {
    contentOnly: true,
  }
);

/*
  import('foo.js', ["deps.js"])
  "__VITE_PRELOAD__"
*/
console.log(s.toString());

s.replace(new RegExp(`"${mark}"`, 'g'), 'void 0');

/*
  import('foo.js', void 0)
  void 0
*/
console.log(s.toString());

To change this, it will need to store positions at line 355 and then do the replace without s.replace at line 375 with skipping the stored positions.
Should I do so? (It's going to be easier than I first thought.)

[bluwy]

To change this, it will need to store positions at line 355 and then do the replace without s.replace at line 375 with skipping the stored positions.
Should I do so? (It's going to be easier than I first thought.)

Sounds like a good thing to do now that I re-look the code, should improve perf too.

[sapphi-red]

I have changed it 👍