Fix webpack deprecations (fix #1126)

[g-plane]

This PR should remove some of webpack deprecation warnings.

[johnnyreilly]

@sheetalkamat has a PR which drops support for older versions of TypeScript here: #1136

When that's merged we can take a look at your PR - it only seems to be failing on older versions of TypeScript.

[g-plane]

It seems that these are weird failures, and I'm not sure whether upgrading webpack will fix these or not, because webpack 4.37 (and newer versions) will check the current loader context is null or not.

[johnnyreilly]

Very strange....

[g-plane]

I've confirmed that upgrading webpack will solve the failures in CI, as those failures also can be reproduced on my local computer. Can I open another PR to upgrade webpack? If not, we may need to add some hacky code to check the loader context.

[johnnyreilly]

Yeah sure - I'd like to decouple the upgrade of webpack from this change if that's okay. So upgrade webpack first and loop back to this next.

[g-plane]

PR for upgrading webpack is created: #1140 .

[g-plane]

I've marked this PR as ready for review, however I don't know how to address the problems at AppVeyor.

[johnnyreilly]

AppVeyor has had a bad day - let's see if it fixes up now.

[g-plane]

Maybe we can migrate to GitHub Actions in the future.

[johnnyreilly]

We're already using GitHub actions, but it doesn't cover the use case that AppVeyor provides; namely running CI on Windows.

Maybe Azure pipelines has something to offer - I haven't taken a look in a while. I did start looking here though:

#856

[johnnyreilly]

Good job! Do you want to increment the package.json and add an entry to the CHANGELOG.md?

[g-plane]

I will. By the way, GitHub Actions supports Linux, Windows and macOS.

[johnnyreilly]

Really? Did not know that! That said, I never managed to get comparison tests passing with GitHub actions. But that was the early days

[g-plane]

Maybe we can try it after this PR.

[g-plane]

I've updated package.json and changelog. Is this OK?

[johnnyreilly]

Looks good! Let's wait for Travis to get happy then we can merge

[johnnyreilly]

My feelings on AppVeyor right now

[g-plane]

All passed now.

[johnnyreilly]

Shipping https://github.com/TypeStrong/ts-loader/releases/tag/v8.0.1 - thanks for your work!