bug: file missing from coverage

[mikeal]

• Version: 7.2.0
• Platform: Linux, Node.js v14.5.0

I’m seeing this error:

file: /root/brrp/src/rollup-iter.js error: TypeError: Cannot read property 'sources' of null
    at V8ToIstanbul.load (/root/brrp/node_modules/v8-to-istanbul/lib/v8-to-istanbul.js:46:34)
    at Report.getCoverageMapFromAllCoverageFiles (/root/brrp/node_modules/c8/lib/report.js:88:25)
    at async Report.run (/root/brrp/node_modules/c8/lib/report.js:59:20)
    at async exports.outputReport (/root/brrp/node_modules/c8/lib/commands/report.js:27:3)
    at async /root/brrp/node_modules/c8/bin/c8.js:39:9

As a result the file src/rollup-iter.js is missing from coverage and c8 passes the full coverage check :(

You can reproduce by running the tests in https://github.com/mikeal/brrp

Sorry for this being a little terse, I plan to return to this and debug a little bit more. It looks like it’s in v8-to-istanbul so I can at least track it down more, maybe even send a fix, but I wanted to get this logged before I forgot about it and moved on :)

[bcoe]

@mikeal we'll make an effort to patch this weekend.

I'm pretty confident it will be a weird edge-case in v8-to-istabul related to paths, and not some systemic issue. If you grep, coverage/tmp, does it have rollup-iter.js?

[bcoe]

@mikeal okay, I have a fix incoming for this for c8, it uncovered a bug with Node.js' source map implementation which I am going to patch at the same time.