[Bug]: Alias Not Working

[PointSingularity]

Version

System:
    OS: macOS 15.3.1
    CPU: (12) arm64 Apple M2 Pro
    Memory: 102.72 MB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Browsers:
    Chrome: 133.0.6943.127
    Edge: 133.0.3065.82
    Safari: 18.3
  npmPackages:
    @rsbuild/core: ^1.2.8 => 1.2.11

Details

It seems that aliasing is not working properly for Rsbuild, when it works for Rspack.

I tried to make the two configs pretty much the same, but still no luck.

Reproduce link

https://github.com/PointSingularity/rsbuild-repro

Reproduce Steps

Run npm i first.

Rspack works:

npm run build:rspack

Rsbuild does not:

npm run build:rsbuild

Error:

❯ npm run build:rsbuild

> repro-rsbuild@1.0.0 build:rsbuild
> rsbuild build

  Rsbuild v1.2.11

error   Compile error:
Failed to compile, check the errors for troubleshooting.
File: repro-rsbuild/src/index.ts:1:1
  × ESModulesLinkingError: export 'constant' (imported as 'constant') was not found in './module' (module has no exports)
   ╭─[2:12]
 1 │ import { constant } from './module';
 2 │ console.log(constant);
   ·             ────────
   ╰────

File: repro-rsbuild/src/module/index.ts:1:1
  × Cannot find module './example' for matched aliased key './example'
  help: Found module './example.ts'. However, it's not possible to request this module without the extension
        if its extension was not listed in the `resolve.extensions`. Here're some possible solutions:

        1. add the extension `".ts"` to `resolve.extensions` in your rspack configuration
        2. use './example.ts' instead of './example'

 @ ./src/index.ts

error   Failed to build.
error   Rspack build failed!
    at file://repro-rsbuild/node_modules/@rsbuild/core/dist/index.js:5638:87
    at finalCallback (repro-rsbuild/node_modules/@rsbuild/core/node_modules/@rspack/core/dist/index.js:14780:9)
    at repro-rsbuild/node_modules/@rsbuild/core/node_modules/@rspack/core/dist/index.js:14812:16
    at done (repro-rsbuild/node_modules/@rspack/lite-tapable/dist/index.js:473:13)
    at promise.then.index (repro-rsbuild/node_modules/@rspack/lite-tapable/dist/index.js:493:25)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)

[hasnum-stack]

try
'./example': path.resolve(__dirname, 'src/module/example.alias'),

[hasnum-stack]

run DEBUG=rsbuild npm run build:rsbuild, /dist/.rsbuild/rspack.config.web.mjs

[PointSingularity]

try './example': path.resolve(__dirname, 'src/module/example.alias'),

So this worked, thank you!

Here are the differences:

https://www.diffchecker.com/L8kbYtRj/

Is there a reason why this is not working in rsbulid compared to rspack?

[hasnum-stack]

in rsbuild, aslias relative paths need to be turned into absolute paths.
/rsbuild/packages/core/src/plugins/resolve.ts, function ensureAbsolutePath

[PointSingularity]

in rsbuild, aslias relative paths need to be turned into absolute paths. /rsbuild/packages/core/src/plugins/resolve.ts, function ensureAbsolutePath

Ah I see, thanks!

According to the docs it should behave the same as Rspack, so this is a bug or the docs will have to change

[chenjiahan]

We will update the documentation, thank you

[hasnum-stack]

in rsbuild, aslias relative paths need to be turned into absolute paths. /rsbuild/packages/core/src/plugins/resolve.ts, function ensureAbsolutePath

Ah I see, thanks!

According to the docs it should behave the same as Rspack, so this is a bug or the docs will have to change

A new discovery: In a TypeScript project, configuring paths can make aliasing effective.

[PointSingularity]

@chenjiahan Thanks for quickly updating the docs!

Is it possible to pass the aliases from Rsbuild to Rspack in the tool config, so my alias setup would work directly?

[chenjiahan]

yes you can use tools.rspack.resolve.alias