Support monorepo

[ahnpnl]

Issue :

At the moment, ts-jest doesn't support well monorepo (typescript composite, yarn workspace, lerna etc..). This issue contains all related issues to monorepo:

#1341 : Cannot use rootMode upward for babel config (fixed via #1370)
#1336 : Error Unable to require d.ts for yarn workspace and typescript composite. (fixed via #1385)
#1333: Use wrong version of typescript in yarn workspace (fixed via #1377)
#1277 : Cannot collect coverage with custom compiler e.g ttypescript for lerna workspace.
#1134 : Compatibility with yarn workspaces pnp
#1109 : Cannot import mixin in yarn workspace and typescript compsite

Expected behavior :

Support monorepo out of the box or at least for common ones like yarn workspace, typescript composite, lerna.

Minimal repo :

Example repos are in those above issues

Problem

At the moment ts-jest is lack of helps. We would need community's help in tackling this issue. Feel free to contribute PRs if you have good ideas related to this issue.

cc @kulshekhar

[kulshekhar]

It would be good to add this support. That said, I personally only use ts-jest actively in non-monorepos so this will need help from others (the code and the related tests)

[arvigeus]

#1341 is related too - I got it when trying to setup a monorepo.

[quadgod]

🐛 ;)))

• Not working coverage collection for symbolic links.
• Typescript setup not working with symbolic links but JS works.

To Reproduce

I made example project: https://github.com/nomadzetetic/monorepo.
Project contains 2 folders: /account and /shared. /account/src/shared -> symbolic link to /shared folder.

Steps to reproduce the behavior:

1. Pull this example project https://github.com/nomadzetetic/monorepo
2. cd account
3. npm install
4. npm run test

Expected behavior

In coverage report should be files from account/src/shared.

Link to repl or repo (highly encouraged)

repl.it demo

envinfo

System:
    OS: macOS 10.15.4
    CPU: (12) x64 Intel(R) Core(TM) i7-8850H CPU @ 2.60GHz
  Binaries:
    Node: 12.13.0 - ~/.nvm/versions/node/v12.13.0/bin/node
    Yarn: 1.21.1 - ~/.yarn/bin/yarn
    npm: 6.14.5 - ~/.nvm/versions/node/v12.13.0/bin/npm
  npmPackages:
    jest: ^26.0.1 => 26.0.1 

[ahnpnl]

@quadgod coverage collection isn’t taken care by ts-jest. We would solve only the 2nd issue which is about TypeScript

[octogonz]

Heft is an interesting alternative for integrating Jest+TypeScript in a monorepo scenario.