My name is mono.ts. I'm a minimal example of a typescript mono-repo.

Unlike many similar examples I can do the following, before you build anything:

/packages/line/package.json:

"test": "mocha --require ts-node/register --require tsconfig-paths/register test/*.ts"

If you click on @geo/point (/packages/line/src/index.ts):

import { Point, getDistance } from '@geo/point';

VScode will take you to /packages/point/src/index.ts

• Yarn Workspaces
• Lerna
• Typescript 3 Project References
• Mocha (using ts-node/register)

There are basically two parallel typescript configuration hierarchies.

This tree is using aliases (or paths in typescript world). This allows VSCode to reference the correct files, and tests to run.

• /packages/tsconfig.base.json (common configuration for both pre-build and build configurations)
  • /packages/tsconfig.json
    • /packages/line/tsconfig.json

This tree uses typescript's project reference for optimised builds.

• /packages/tsconfig.base.json
  • /packages/tsconfig.build.json
    • /packages/point/tsconfig.build.json
    • /packages/line/tsconfig.build.json

Note that to build the packages you run (/package.json):

"build": "tsc --build packages/tsconfig.build.json"

This is allegedly better than letting yarn or lerna build the packages in turn based on the dependency tree.