nyc does not work with symlinks

I reproduced the issue in this repo: https://github.com/aalexgabi/nyc-symlink-problem/commit/3ce1fe85f2f8bb723a2ede92bf1d9a324655c8e2 When I don’t use a symlink it does work: https://github.com/aalexgabi/nyc-symlink-problem/commit/9da9355e8111233e8efa38f85aef9de2f6fd713c

This was reported many times (not sure all issues here are due to symlinks) but not fixed:

• https://github.com/istanbuljs/nyc/issues/962
• https://github.com/istanbuljs/nyc/issues/472
• https://github.com/istanbuljs/nyc/issues/741
• https://github.com/istanbuljs/nyc/issues/833

Expected Behavior

I should have symlinked files from node_modules included:

running
working
ran
-----------------------|---------|----------|---------|---------|-------------------
File                   | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
-----------------------|---------|----------|---------|---------|-------------------
All files              |     100 |      100 |     100 |     100 |                   
 src                   |     100 |      100 |     100 |     100 |                   
  test.js              |     100 |      100 |     100 |     100 |                   
 src/node_modules/work |     100 |      100 |     100 |     100 |                   
  index.js             |     100 |      100 |     100 |     100 |                   
-----------------------|---------|----------|---------|---------|-------------------

Observed Behavior

I don’t have symlinked files from node_modules included:

running
working
ran
----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |     100 |      100 |     100 |     100 |                   
 test.js  |     100 |      100 |     100 |     100 |                   
----------|---------|----------|---------|---------|-------------------

Troubleshooting steps

• still occurring when I put cache: false in my nyc config

Environment Information

% npx envinfo@latest --preset nyc
npx: installed 1 in 0.741s

  System:
    OS: Linux 5.5 Manjaro Linux
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 887.34 MB / 15.52 GB
  Binaries:
    Node: 13.7.0 - ~/.fnm/current/bin/node
    Yarn: 1.22.0 - /usr/bin/yarn
    npm: 6.13.6 - ~/.fnm/current/bin/npm
  npmPackages:
    nyc: ^15.0.1 => 15.0.1 

[coreyfarrell]

Coverage of files outside the project isn’t supported. It might work for you to tweak your settings as follows:

"cwd": "..",
"include": [
  "project/src/**",
  "lib/**"
]

The cwd says that the project root is the directory above process.cwd(), the include options are modified to be relative to the explicitly set cwd. Note that unlike other options the cwd option has slightly different meaning when provided to CLI vs when provided in config. If you ran nyc --cwd .. then this would prevent nyc from finding project/.nycrc. Thus you have to put the cwd option into project/.nycrc.

[rwalle61]

@coreyfarrell thanks for the cwd suggestion - it worked like a charm! Now I can test coverage across multiple packages in my monorepo (a yarn workspace):

"cwd": "..",
"include": [
  "packageA",
  "packageBRequiresPackageA"
]

Think it would be worth documenting this for people using monorepos