Extending tsconfig.json file doesn't seem to extend anything

Question

I have a project from which I need to build two different products. Say I have

./src/advanced
./src/basic

All code is written in Typescript so I need to compile this with tsc

Because of this, I created 3 tsconfig files

tsconfig-base.json

{
  "compilerOptions": {
    "module": "commonjs",
    "declaration": true,
    "noImplicitAny": false,
    "removeComments": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es6",
    "sourceMap": true,
    "outDir": "./dist",
    "baseUrl": "./src",
    "lib": ["es2018", "dom", "dom", "dom.iterable", "es6"],
    "importHelpers": true,
  },
  "exclude": ["node_modules", "**/*.spec.ts","dist"]

Now to build the basic product I have

tsconfig-basic.json

{
  "extends": "./tsconfig-base.json",
  "compilerOptions": {
    "noEmitHelpers": true
  },
  "files": [
     "basic/main.ts"
  ]
}

And I compile as follows

$> tsc -p ./tsconfig-basic.json

Now I have 2 issues

1) The file basic/main.ts cannot be found, its looking in ./basic/main.ts while it should have been ./src/basic/main.ts. Why is baseUrl not prepended?

2) If (1) is fixed, the compiled files are not written to ./dist. Why is "outDir": "./dist from the base file not used here? When I add the outDir to tsconfig-basic.json it works as expected

Anyway, it looks like that extending here doesn't work, or works differently than I expect. Any suggestion how to improve my setup?

Solution 1

1) baseUrl is only meant to be used with bundlers like webpack. See discussion on TypeScript/10866

2) This is unfortunately by design. See issue TypeScript/29172

Quote Wesley Wigham (Microsoft Employee):
Path-based compiler options (outDir, outFile, rootDir, include, files) are resolved from the config file they're found in)

You will need to repeat the outDir for every tsconfig.json file you have.

Solution 2

There is a trick though. If you create a symlink to the base Tsconfig file from a relevant directory and extend the symlinked version rather than the original, all the paths will be resolved according to your expectations.