[Bug]: SourcemapDevToolPlugin uses the incorrect contenthash - outputs assets contenthash rather than sourcemaps contenthash

[cblagg]

System Info

OS: macOS 13.6.3
CPU: (10) arm64 Apple M1 Pro
Memory: 7.02 GB / 32.00 GB
Shell: 5.9 - /bin/zsh

Binaries:
Node: 22.11.0 - ~/.nvm/versions/node/v22.11.0/bin/node
npm: 10.9.0 - ~/.nvm/versions/node/v22.11.0/bin/npm

Browsers:
Chrome: 130.0.6723.117

npmPackages:
@rspack/cli: 1.1.4 => 1.1.4
@rspack/core: 1.1.4 => 1.1.4

Details

When using SourceMapDevToolPlugin, the produced sourcemaps filename outputs the incorrect hash in the filename template for [contenthash]. It outputs the assets contenthash in this token rather than the sourcemaps contenthash.

This behavior is unexpected and different to behavior within Webpack.

The current RSPack behavior can result in sourcemap files overwriting each other with the same name despite different content - when a underlying source change is only types.

When using the SourceMapDevToolPlugin, it is expected that the [contenthash] in it's configuration of the filename refers to the content hash of the sourcemap.

Webpack explicitly creates the [contenthash] for naming the sourcemap here.

Reproduce link

https://github.com/cblagg/rspack-sourcemap-name-repro

Reproduce Steps

Steps to reproduce:

1. npm i
2. Run: ENTRY=untyped npm run build:webpack
3. Run: ENTRY=typed npm run build:webpack
4. Run: ENTRY=untyped npm run build
5. Run: ENTRY=typed npm run build
6. Observe dist/webpack contains 3 files. Where the sourcemap files are named with the pattern of:

• {sourcemaps_content_hash}-{entry_name}-{entry_content_hash}-min.js.map

7. Observe dist/rspack contains only 2 files. Because one is overwritten, due to the entries contenthash being used rather than the sourcemaps content hash, resulting in the pattern:

• {entry_content_hash}-{entry_name}-{entry_content_hash}-min.js.map

When using the SourceMapDevToolPlugin, it is expected that the [contenthash] in it's configuration of the filename refers to the content hash of the sourcemap, not the content hash of the entry asset.