A minimal reproduction for the issue nyc#1353 that nyc doesn't seem to instrument ES module code as expected.
After cloning the project, run these commands to reproduce:
npm install
npm run test
At this point, you will see the following output.
2 tests passed
----------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files | 0 | 0 | 0 | 0 |
----------|---------|----------|---------|---------|-------------------
Original reproduction environment.