feat!: support source map with multiple sources

[MoLow]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build 444

• 64 of 64 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.7%) to 96.204%

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Totals
Change from base Build 440:	0.7%
Covered Lines:	539
Relevant Lines:	556

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💛 - Coveralls

[MoLow]

I have seen #91 after implementing this.
my soultion seemd a little cleaner, I have compared results of runs and they look the same

[MoLow]

@bcoe @lukeapage wdyt?

[benjamingr]

@bcoe any chance this could get a review ?

[bcoe]

@MoLow thank you for taking a crack at this, I'll make an effort to give you a more thorough review soon.

[bcoe]

this seems weird to me, I wouldn't have expected us to need to update the snapshot for the non-multi-source use-case, and it looks like this updates the snapshot with empty information.

[MoLow]

@bcoe this was indeed a bug, I fixed it

[bcoe]

@MoLow sorry for the slow review, this implementation seems close to what I was expecting we'd do 👍

Great work, and thank you @LukePage for getting this in motion.

[bcoe]

Hey @MoLow I've been working on dual mode modules for yargs-parser, so actually better understand the problem we're trying to solve here and could give better review.

Issues with yargs-parser

I tried running c8 against yargs-parser with your branch of v8-to-istanbul. The results for text output are very promising:

However, when I open an HTML report there are some issues:

My guess is we're missing resolving a path somewhere?

Issues with c8 test suite

I also ran the test suite against c8 and am getting a couple additional path related failures:

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I bet there's a chance these issues are related, and we're just missing a resolve somewhere.

[bcoe]

Left some feedback @MoLow 👋 it seems like this work is a good chunk of the way there, just a couple of path related bugs we need to hunt down.

[bcoe]

@MoLow update, I got everything debugged; your work was 99% of the way there 😄

[bcoe]

awesome work @MoLow 🎉

Thank you for seeing this feature over the finish line. And thank you @lukeapage for kicking of this work.