Minimalize differences between CLI and Node.js API and move CLI in `webpack-cli`

[SpaceK33z]

There are some differences between the CLI and Node.js API that make webpack-dev-server a lot harder to use for people. Most differences are documented in the wiki, but users often don't look at this. They also shouldn't have to.

The first problem is that the CLI in inline modus (which is the default since v2), automatically adds an entry to the webpack config. When you use the API, you need to do this manually. What makes it more confusing is that there is is a inline option, but that only has effect when using the CLI.

The second problem is that, when using --hot, the CLI adds an entry to the webpack config and adds the HotModuleReplacementPlugin. In the API, you need to add those two things yourself, as well as set hot: true.

The idea was that the API shouldn't mutate the webpack config. This is indeed iffy, but perhaps there are other ways to do this without mutating the config. Or if there is not, maybe it's worth it to mutate the config? The current situation causes many issues with users.

Related to #106, but that discussion is quite old and not all points are valid anymore.

cc @bebraw

[axe312ger]

You marked it for version 3. Might it be possible to earlier make more clear what the CLI attaches/changes at the configuration?

Still have issues with public path, my webpack config works fine with CLI but not with the Node API :(

[SpaceK33z]

@axe312ger, #615 will introduce config validation. Feel free to join that discussion if you have more ideas for validation. We're also working on better docs, which will be released with v2.

[alecmev]

This definitely needs to be addressed.

For example, look at the official docs on React + HMR and the react-hot-boilerplate: both load the WDS client twice. This means that even those intimate with Webpack don't have full understanding of the difference between CLI and Node API.

Also, speaking of config differences, I can see people starting out with CLI and then switching to programmatic use, doing something like new WebpackDevServer(compiler, webpackConfig.devServer), and then not understanding why the client isn't being inlined. Or vice versa, going to CLI and not understanding why the client is being inlined twice (or not even noticing it).

[wesleymostien]

any progress ?

[shellscape]

@wesleymostien none yet. this is planned for the v3 work. protip: if there were commits against this issue/task, you'd see github list those referenced commits in this issue along with the comments - they make it easy to know if there's been progress without having to post follow-up comments 😄