sourcemaps not quite working: lerna+typescript 3 project references

[axelnormand]

Issue :

Here is a sample repo trying to create a common publishable component library as used by 2 apps. All in one lerna monorepo. Includes jest, styled components, babel 7, ts-jest etc.
https://github.com/axelnormand/react-typescript-monorepo

The strange thing that's happening is the jest --coverage report is only covering the common submodule and not the 2 apps. I get 100% coverage in the common tests, but 0 in app1 and app2.

Have tried the babel-jest preprocessor to no avail
Perhaps it's a source map generation thing in a tsconfig?

Any help or clues much appreciated, I found it quite tricky to all get working.

Expected behavior :

Jest coverage report covers app1 and app2

[axelnormand]

Actually think its a jest issue :)
something to do with multi-project setting
jestjs/jest#5457