SWC generate invalid source map when inputSourceMap is provided

[noyobo]

Describe the bug

I tested version 1.7.8-nightly-20240807.1, not report any error. But the generated sourcemap to be unavailable

1. Use swc transform a.js & a.js.map

console.log('==== use swc transform es6 to es5 ====');
// transformed successfully
const result = await transform(fileCode, {
  filename: 'a.js',
  sourceMaps: true,
  inputSourceMap: fileMap,
  jsc: { target: 'es5' },
  minify: true,
  module: { type: 'commonjs', strictMode: false },
});

fs.writeFileSync('./a.swc.js', result.code);
fs.writeFileSync('./a.swc.js.map', result.map);

2. Validate transformed sourcemap

const fs = require('fs');
const path = require('path');
const { SourceMapConsumer } = require('source-map'); // 0.7.4

async function verifySourcemap({ file, map, offset, line }) {
  const sourceMap = fs.readFileSync(map, 'utf8');
  const consumer = await new SourceMapConsumer(sourceMap);
  const originalPosition = consumer.originalPositionFor({
    line: line,
    column: offset,
  });
  if (originalPosition.source === null) {
    // @swc/core@nightly always return null for source
    return null;
  }
  let miniCode = fs.readFileSync(file, 'utf8');
  miniCode = miniCode.split('\n')[line - 1];
  miniCode = miniCode.substring(offset - 20, offset + 20);

  const source = consumer.sourceContentFor(originalPosition.source);
  const code = source.split('\n')[originalPosition.line - 1];

  // lgt 1.7.6 versions that works
  return { sourceFile: originalPosition.source, code, miniCode };
}

verifySourcemap({
  file: path.join(__dirname, 'a.swc.js'),
  map: path.join(__dirname, 'a.swc.js.map'),
  line: 1,
  offset: 207274,
}).then((result) => {
  console.log('swc:', result);
});

Input code

No response

Config

No response

Playground link (or link to the minimal reproduction)

https://github.com/noyobo/swc-issues/tree/transform-compare

yarn install
node  ./swc/build.mjs

SWC Info output

No response

Expected behavior

When inputSourceMap is provided, the sourcemap after transfrom is parsable

Actual behavior

No response

Version

1.7.8-nightly-20240807.1

Additional context

No response

[jiby-aurum]

Have the same issue, upgrading swc_core from 0.99.6 to any never version breaks processing of source provided with an existing source map.

[kdy1]

I reverted #9052 with #9437 because sourcemap::SourceMap::adjust_mappings has a bug. I'll investigate further. IIRC, it was about duplicate entry in the inputSourceMap.

[kdy1]

https://raw.githubusercontent.com/noyobo/swc-issues/transform-compare/a.js.map still has a duplicate filename.

See getsentry/rust-sourcemap#89

[noyobo]

👍 Solved, delete the repo

[kdy1]

Can you update repro?

[noyobo]

Can you update repro?

Sorry I made a mistake, Transform it again and it was correct.

[jiby-aurum]

@kdy1 works perfectly with swc core 0.101.4, thanks for the super quick fix.

[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.