reported uncovered lines that actually have been covered

Link to bug demonstration repository

https://github.com/lichader/nyc-demo

Expected Behavior

Expected 100% coverage

Observed Behavior

Reporting Branch coverage as 50%.

I made a basic repo to show what the problem is. I have a simple js file here that just prints something in the log. From console output I pasted below, you can see that the code inside the if block is hit. But nyc reported lines 8-16 are uncovered, which is quite strange. Not sure where I did wrong or it is a bug.

This is the output here:

 π nyc-poc master ✗ ❯ npm run cover:unit

> unit@1.0.0 cover:unit /Users/me802707/work/rpeng/nyc-poc
> nyc --all npm run test


> unit@1.0.0 test /Users/me802707/work/rpeng/nyc-poc
> mocha tests/*.test.js --reporter mocha-junit-reporter --reporter-options mochaFile=./test-results/test-results.xml

found bar: user1
found bar: user2
bar is found
ERROR: Coverage for branches (50%) does not meet global threshold (90%)
----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files |     100 |       50 |     100 |     100 |
 foo.js   |     100 |       50 |     100 |     100 | 8-16
----------|---------|----------|---------|---------|-------------------

Troubleshooting steps

run command: npm install && npm run cover:unit

Environment Information

  System:
    OS: macOS 11.2.1
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 51.58 MB / 16.00 GB
  Binaries:
    Node: 14.15.4 - ~/.nvm/versions/node/v14.15.4/bin/node
    npm: 6.14.10 - ~/.nvm/versions/node/v14.15.4/bin/npm
  npmPackages:
    nyc: 15.1.0 => 15.1.0

Thank you

[hedocode]

I have the same problem on if statements, however, I wrote console.log statements into these ifs and they are properly displayed in the console

[andrecadete]

Hi dhensby,

Makes sense for actual branches, but these are mocked Constructor arguments, how exactly does your example relate to that use-case?

Either way, once we cover the remaining branches I’ll let you know if that fixed it. But seems silly, it should instead state which lines are partially tested when less than 100% of branches were tested. There’s no way it can know which constructor arguments are used in untested branches without knowing which lines those are. So indicating those lines as untested or (a new feature) as partially tested would have actual use while indicating constructor arguments says very little.