Typescript 3 --build ignores baseUrl

[marcos-diaz]

TypeScript Version: 3.0.0-rc

Search Terms: baseUrl

Code

{
  "compilerOptions": {
    "baseUrl": "./src",
    ...
  }
}

tsc --build tsconfig.json

Expected behavior:
Now that Typescript 3.0 compiler claims to be a also a simple project builder, I would expect compiled output to resolve absolute imports to itself based on baseUrl setting.

Actual behavior:
It still outputs unresolved require paths.

[mhegazy]

Can you share more details?

[marcos-diaz]

I can try, just imagine you have a project/module called fancylib, you possibly have a bunch of top level files at root level in your project, and a folder src with the actual code of the lib.

Then in the lib some files will reference other files, the easy way is to do relative imports, for example in fancyness.ts you would do import {Magic} from './utils', but some people argue that doing relative imports is a bad practice, that makes refactors harder, etc... so they would like to do absolute imports better, as import {Magic} from 'fancylib/utils' or simply import {Magic} from 'utils'.

This was only possible with Webpack/Gulp or other build systems, by using the tsconfig setting baseUrl, but was not possible with TSC since it WAS not a build tool, just a compiler, so it ignored baseUrl.

But now TSC is actually also a basic build tool, so is a reasonable expectation that if someone does import {Magic} from 'fancylib/utils' in a project/module called fancylib, with tsc --build ..., then TSC should output JS as const utils = require("<baseUrl>/utils"); utils.Magic ...

[mhegazy]

is this the same as #25613?

[marcos-diaz]

I don't think is the same

[typescript-bot]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.