Code coverage report is empty

Given the following file structure:

src
 - example.js
test
 - my-first-test.js

example.js

module.exports = {
    everything: function () {
        return 'cool';
    }
}

my-first-test.js

let { everything } = require('../src/example');

export function testThatEverythingIsCool(t) {
    let result = everything();
    t.assert(result === 'cool', 'Make sure that everything is cool');
}

Running npx luna test/* --node --verbose results in the following:

🌙  Running tests…
✔︎  [test/my-first-test.js] testThatEverythingIsCool
   All tests passed!

----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |        0 |        0 |        0 |        0 |                   |
----------|----------|----------|----------|----------|-------------------|

=============================== Coverage summary ===============================
Statements   : Unknown% ( 0/0 )
Branches     : Unknown% ( 0/0 )
Functions    : Unknown% ( 0/0 )
Lines        : Unknown% ( 0/0 )
================================================================================

   HTML coverage report available at coverage/lcov-report/index.html
   Took 0.55 seconds

Maybe I’m running it wrong somehow, but shouldn’t it be showing 100% coverage for this simple test?

[ccampbell]

Aha! I found a solution…

If you do

npm install nyc

Then run as

npx nyc luna test/* --node --verbose

it works!

[ccampbell]

Haha yup. that looks like a bug with yargs though. Or at least my expectation of how it should work. If you pass --no-coverage=1 it works, but passing it alone does not work.

Oh wow. It is the library itself being smarter than I am. If you name a flag --no-{flag} it comes in as flag: false. Instead of 'no-{flag}': true which was what I expected here. Personally I think the library is trying to be too smart, it should add both, but it is an easy fix