Reset current compilation if file was changed

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• Operating System: Mac OS 10.12.4
• Node Version: 8.11.2
• NPM Version: 5.6.0
• webpack version: 4.29.3
• webpack-dev-middleware Version: 3.5.2

• [] This is a feature request
• This is a bug

Expected Behavior

Current active compilation should reset if file was changed and next compilation should start immediate

Actual Behavior

Current active compilation will finish first if file was changed and only after that - next compilation will start

For Bugs; How can we reproduce the behavior?

I'm using latest koa-webpack + webpack@4.
Start server, change file, after two seconds change file again. As result - two full compilations instead of 2 seconds of first compilation + full second compilation.

Reproduce this with koa-webpack and webpack-dev-middleware by changing a file, waiting two seconds, and changing it again. Trace how the active compilation and the next compilation are scheduled, then verify that the current compilation is reset and the latest change starts a new compilation immediately.