Split changelog into files by version

[jewel-andraia]

and make version changelog file from changelog/UNRELEASED.md when running npm version.

⚠️ fails awkwardly if changelog/vNew.Version.Number.md already exists.

[jewel-andraia]

Maybe check if newChangelog exists first?

[Ajedi32]

I guess this is to make it easier to automate maintenance of the change log? That's pretty cool. Worth noting though that there are a couple minor disadvantages to this approach:

1. It makes it more difficult to Ctrl+F through the CHANGELOG to find out in what version of RES a specific change was implemented.
2. The sort order of the versions in changelog/ won't necessarily be oldest to newest. (E.g. A theoretical 4.7.10 would be sorted before 4.7.9 if you're sorting by name.)
3. It's marginally less discoverable, since you're no longer using the conventional CHANGELOG file in the root of the repo.

These are all definitely solvable problems though:

1. We could include the full, concatinated CHANGELOG in a page on http://redditenhancementsuite.com/
2. No real solution, but the solution for 1 above also lessens the impact of this.
3. We could keep a CHANGELOG.md file in the root that tells people to look in changelog/

[jewel-andraia]

We could include the full, concatenated CHANGELOG in a page on http://redditenhancementsuite.com/

I like the sound of that idea. I set up the known issues page on the upcoming res.com in a similar fashion: http://reddit-enhancement-suite.github.io/knownissues/

We could keep a CHANGELOG.md file in the root that tells people to look in changelog/

Good idea! And a pointer to res.com, too.

[Ajedi32]

Might want to use postversion for this, so that build/version.js isn't using the old version when creating the changelog file. Although, I guess that might mess up the tagging? Hmm... does this work the way I'm imagining it does?

[erikdesjardins]

No, version is what we want to use. preversion has the old version number, version has the new version number and is before the commit (which we want to add to), and postversion is after the commit

[Ajedi32]

Ah, really? Somebody needs to tell npm to update their docs:

preversion, version: Run BEFORE bump the package version

😜

[Ajedi32]

Oh. Haha. They just did: npm/npm@c565d89

[erikdesjardins]

Huh, I'm surprised that's not deployed yet (I guess only on a new npm release?).

The npm version docs go into more detail and seem to be correct:

4. Run the version script. These scripts have access to the new version in package.json (so they can incorporate it into file headers in generated files for example). Again, scripts should explicitly add generated files to the commit using git add.

[Ajedi32]

I guess import/no-commonjs can be removed now since you're using ES6 imports?