bug: tsconfig alias path transpilation regressed in 3.4.1

[liamdebeasi]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Stencil Version

3.4.1

Current Behavior

TSConfig alias paths such as @utils/helper are not being transpiled to their relative paths (i.e. ../../utils/helpers) on build, resulting in warning when consuming the collection target:

[ WARN  ]  Bundling Warning UNRESOLVED_IMPORT
           '@utils/helpers' is imported by
           node_modules/@ionic/core/dist/collection/components/datetime-button/datetime-button.js, but could not be
           resolved – treating it as an external dependency

Expected Behavior

I expect there to be no warning.

System Info

     System: node 16.19.0
    Platform: darwin (22.2.0)
   CPU Model: Apple M1 Pro (8 cpus)
    Compiler: /Users/liamdebeasi/Ionic/ionic/core/node_modules/@stencil/core/compiler/stencil.js
       Build: 1687785553
     Stencil: 3.4.1 🐨
  TypeScript: 5.0.4
      Rollup: 2.42.3
      Parse5: 7.1.2
      Sizzle: 2.42.3
      Terser: 5.18.1

Steps to Reproduce

1. Clone https://github.com/ionic-team/ionic-framework
2. In core run npm install && npm run build.
3. Open core/dist/collection/components/datetime-button/datetime-button.js. Observe that @utils/helper is still an import path at the top.
4. Install Stencil 3.4.0 using npm install @stencil/[email protected].
5. Run npm run build.
6. Open core/dist/collection/components/datetime-button/datetime-button.js. Observe that the correct relative path is specified.

Code Reproduction URL

https://github.com/ionic-team/ionic-framework

Additional Information

• This appears to be fixed in Stencil 4.0.0, however it would be great to get that fixe backported since 3.4.1 is the latest version of 3.x.

[tanner-reits]

@liamdebeasi So, this isn't technically a regression as the behavior in 3.4.1 is how this should behave. The problem is that the root-level transformAliasedImportPaths doesn't actually control the transformations in dist (and subsequently dist-collection that gets synthetically injected as an addition output target). For paths in this output to get transformed, you'll need to have the following in the dist target config:

{
  type: 'dist',
  transformAliasedImportPathsInCollection: true,
  ...
}

We agree it's not ideal to have two flags controlling similar behavior. The plan (as of now) is that the output target specific flag will be removed in the next major release of Stencil and all path transformations will be determined by the root-level transformAliasedImportPaths flag.

The reason this is "fixed" in v4 is because transformAliasedImportPaths and transformAliasedImportPathsInCollection both now default to true.