Webpack incremental build does not work

[Leekao]

According to Webpack5 documentation in order to utilize incremental build I need to pass cache object with type: "filesystem" however that does nothing when I pass it through Grunt-webpack and the documentation for Grunt-webpack refer to cache as a Boolean.

[Leekao]

If anyone in the future wonders how I resolved this issue the solution for me was to remove grunt-webpack and to run webpack from cli using grunt-shell and it indeed builds incrementally.

[evenstensberg]

Makes sense. Grunt suppress output and input a lot more than needed. Like error handling.

[snickell]

I found the problem, this is a straight up bug in grunt-webpack: grunt-webpack never calls compiler.close(), see a description of the issue in webpack's issue tracker webpack/webpack#12342 (comment)

If you look in tasks/webpack.js you can see that compiler is created as const compiler = webpack(webpackOptions);, but compiler.close() is never called. In Webpack 5, compiler.close() is what triggers webpack to write out the filesystem cache before exiting.

[snickell]

Here's a PR with a fairly simple fix that WorksForMe(TM): #250

This makes webpack 5 caching work with grunt-webpack.

[danez]

Fixed with #252