Design Meeting Notes, 2/2/2022

[DanielRosenwasser]

Project References and Multiple Externally-Controlled outDirs

#37378

• "Workspace/monorepo model"

  projects/
  ├── foo/
  │   ├── src
  |   |   └── tsconfig.json
  │   └── out
  ├── bar/
  │   ├── src
  |   |   └── tsconfig.json
  │   └── out
  └── baz/
      ├── src
      |   └── tsconfig.json
      └── out
  

  • When building these, TypeScript looks up from the output directory of each tsconfig.json based on composite projects.

• People putting everything into the same place

  • "Stone soup"? "Melting pot"?

  projects/
  ├── src/
  │   ├── foo
  │   |   └── tsconfig.json
  │   ├── bar
  │   |   └── tsconfig.json
  │   └── baz
  │       └── tsconfig.json
  └── out/
      ├── foo
      ├── bar
      └── baz
  

• Then another iteration on this - the idea that you have multiple output targets.

  projects/
  ├── src/
  │   ├── foo
  │   |   └── tsconfig.json
  │   ├── bar
  │   |   └── tsconfig.json
  │   └── baz
  │       └── tsconfig.json
  ├── win-out/
  │   ├── foo
  │   ├── bar
  │   └── baz
  ├── mac-out/
  │   ├── foo
  │   ├── bar
  │   └── baz
  └── linux-out/
      ├── foo
      ├── bar
      └── baz
  

• Composite projects don't work well here when you have multiple output targets.

  • Need to resolve relative to --outDir
  • So idea: a new flag for this?

• Is this the right way to do this?

  • Feels like a legitimate setup.

• How do these build tools work with symlinks?

  • Need to ask @alexeagle

• Ideas:

  • Relative locations of tsconfigs are used in conjunction with relative locations of outDirs.
    • Compute relative path from app's tsconfig to library's tsconfig. Then you assume that library's output path is always accessible from the same relative paths.

• How does this work with outFile?

  • Can say this doesn't work with outFile.

• What's the general solution here?

  • Fairly narrow problem - is there something broader to consider?
  • Part of this comes down to the issue that there's no true idea of solution-specific settings.
    • Tangent, don't we already have a solution-style tsconfig.json?
      • Yes
      • And projects inherit all their settings from that?
      • No, they all have to extend from the same base tsconfig.

• What is the usual tsconfig.json usually going to specify for outDir?

• What's the flag name?

[alexeagle]

note, as I explained here #37378 (comment)
we can't always assume there is a pair of tsconfig.json files to derive the relative path.