Wrong ranges

[anurbol]

Not necessarily relates to c8, but I was asked to create an issue here.

I have general struggle with coverage features in node.js.

I tried using c8 package and node.js' inspector module.
Neither of them gives correct lineNumber, columnNumber and ranges (startOffset, endOffset), unfortunately.

c8

when I run c8 node test.js where test.js is this file:

function foo() {
  console.log(123)
}

foo()

I get this in the generated report:

{"functionName":"foo","ranges":[{"startOffset":62,"endOffset":99,"count":1}]

Note the startOffset":62 when there is 44 characters total in test.js. I am not even speaking about "endOffset":99.

inspector

after not successing with c8 I tried to place in my test.js code from this example

and run node test.js
then I got this:

{"functionName":"session.post","scriptId":"66","url":"file:///home/nurbol/www/sandbox/test.js","lineNumber":5,"columnNumber":32},"hitCount":0,"children":[16]}

Note the "lineNumber":5 when there is no anything on line number 5!

Then @bcoe gave me an advice to take into accunt require('module').wrapper[0] that is inserted by node.js. But if done so, line number 5 contains session.connect and not session.post (see the json above)!

My setup:

Linux (Lubuntu).
Node 11.2.0 (also tested in 10.13.0 with the same results)
c8 3.2.1

[bcoe]

this is a bug with the header not being removed, because of a breaking change in Node.js around module naming; it will be fixed in future node versions when wrapping behavior changes — the 62 characters is module.wrap not being removed from the offsets.

[anurbol]

Thanks! I got it! So it takes 62 characters, and I should simply always (until fixed node versions) subtract this number to get real offsets! Cool!

[shinnn]

I'm closing this because Node.js v12 has been released.

If you still run into this problem even if you use Node.js v12, feel free to comment more here.