refactor(plugin): v4.0.0

[ryanclark]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior? (You can also link to an open issue here)

Doesn't support webpack 4's new plugin system

What is the new behavior?

It supports webpack 4's new plugin system

Does this PR introduce a breaking change?

• Yes
• No

If this PR contains a breaking change, please describe the following...

• Impact: upgrades webpack-dev-middleware to latest, making node minimum version 6.11.5
• Migration path for existing applications: update to webpack 4

Fixes #314

[iclanton]

Any word on when this is going to go in and 3.0.0 is going to get released?

[limonte]

FYI, package-lock.json is a joke, do not include it in PRs without strong reasons for that:

• https://stackoverflow.com/q/45022048/1331425
• why is package-lock being ignored? npm/npm#17979

yarn.lock works just like expected though, but still both package-lock.json and yarn.lock are completely out of scope of this PR.

[a-tarasyuk]

+1 to question from @iclanton. Are there any issues that block review/merge? Or maybe need help to fix issues in order to deploy this update.

[michael-ciniawsky]

I will release this under the @next tag on npm once https://status.npmjs.org/incidents/gbk5bjx1169j is resolved so folks can try it out :)

[michael-ciniawsky]

@rynclark Could you do me a favor and split the commits this time with the following commit messages for the CHANGELOG 🙃

chore(package): update `webpack-dev-middleware` v1.12.0...3.0.1

BREAKING CHANGE: requires `node >= v6.9.0`

refactor(karma-webpack): upgrade plugin system (`tapable`)

BREAKING CHANGE: requires `webpack >= v4.0.0`

[michael-ciniawsky]

@rynclark Thx, nice work! :P

[michael-ciniawsky]

>= 6.9.0

[michael-ciniawsky]

function is needed here to keep the context ? :)

[a-tarasyuk]

I think yes, as there is the second argument in line 150 which set this for the callback. The plugin uses ES5 syntax, not ES6, so I think it is ok to use the function here.

[a-tarasyuk]

@michael-ciniawsky

I will release this under the @next tag

Are there changes which need to be done in order to release stable version?

[limonte]

Are there changes which need to be done in order to release stable version?

https://github.com/webpack-contrib/karma-webpack/milestone/1

[a-tarasyuk]

@limonte thx. Is there a change that webpack-4 support will be released early? There are some issues which can take a lot of time, like issues related to performance.

[michael-ciniawsky]

Released in v4.0.0-beta.0 🎉 Thx

npm i -D karma-webpack@next

[thijstriemstra]

@michael-ciniawsky can you give any ETA for karma-webpack 4.0.0?