Expand default extension list

[coreyfarrell]

Since enabling --exclude-after-remap we've had some issue with TS projects. We need to add .ts to the default extension list. While we're at it we should also add .cjs and .mjs. Any other extensions we should instrument or report on by default?

This is a potentially breaking change so it will be for nyc@15.

CC @bcoe @JaKXz

[bcoe]

@coreyfarrell this seems like a reasonable list to me 👍

[JaKXz]

.jsx and .tsx would be good to add

[coreyfarrell]

Additional question, should we continue to "force" .js into the list? Should these other extensions be similarly forced? I'm leaning towards yes for .js and no for others. Though this is inconsistent with how exclude works (replacing defaults), I'd rather not deal with the fallout if some people configured extension: ['.ts'] but need .js to be included.

[bcoe]

I don't know the answer to the forcing question off the top of my head; perhaps when we have a bit of time we could setup a .jsx and .ts repo for both ts-node and an explicit compile step -- see if we can figure out default configuration that works relatively well for both use-cases, and is easy to modify where it doesn't work well.

[Raynos]

I ran into this as well when upgrading nyc. Thanks for fixing this.

[Enet4]

Just to let the devs know that I'm looking forward to a new release of nyc. I was expecting the default extensions to include .ts, but it appears that these changes are still not applicable to the latest version.

[coreyfarrell]

@Enet4 the next release will be semver-major, you can watch for progress at #1104. We're working on it but are still dealing with some blockers. No ETA yet.