docs(configuration): Change chunkhash to hash

[ematipico]

The filename options supports hash and not chunkhash.
chunkhash is only for chunkFilename option.

[skipjack]

Thanks for your contribution but chunkhash is available for filename (see the table) and should be the default based on the practices recommended in the caching guide. Could you document why this change is necessary or provide an example using the latest version of webpack where this doesn't work?

[skipjack]

Related: #1436

[ematipico]

That's weird. Webpack 3.3.0 was complaining about that, saying that I needed to use hash instead of chunkhash for filename

[skipjack]

Hmmm I just used chunkhash in TheDutchCoder/webpack-guides-code-examples#17 with webpack 3.3.0 and didn't get any errors. Can you maybe pull that example and see if you are able to reproduce the issue? It may be a bug with webpack 3 but as far as I know chunkhash should be available.

[skipjack]

Maybe it's some combination of things in your config that's causing that error to be thrown, even if that's the case though it may be a bug or maybe the error isn't detailed enough. Or, maybe a breaking change was introduced that I'm not aware of but this wasn't mentioned in either of the release docs issues ( #1318 or #1388 ) or in the main repo's changelog as far as I know.

cc @webpack/documentation-team

[ematipico]

OK probably I narrowed down the issue.

My output config

    output: {
        path: path.resolve(path.join(__dirname, '/')),
        filename: '[name].[chunkhash].js',
        chunkFilename: '[name].[chunkhash].js',
        publicPath: '/'
    }

[name].[chunkhash].js
Cannot use [chunkhash] for chunk in '[name].[chunkhash].js' (use [hash] instead)

Probably it's not possible to use [chunkhash] inside filename when you have chunkFilename defined. I didn't find anything inside the documentation though

[skipjack]

I think the maybe that error is actually flagging the use of [chunkhash] within chunkFilename. Maybe for chunkFilename only [hash] is supported. I agree that this error is a bit confusing. I'll re-open so we can get some clarification.

cc @bebraw @sokra @TheLarkInn

[sokra]

With HMR enabled you can't use [chunkhash] for technical reasons.

For dev builds with HMR -> use [hash].

[ematipico]

The configuration that I am using doesn't use the HMR. The local web server is launched using another technology. Is it because there's the --watch flag?

[skipjack]

Is it because there's the --watch flag?

It seems that's likely the case, e.g. if webpack is in "Watch Mode" -- [chunkhash] is forbidden. I'll let @sokra clarify but if this is the case maybe we should just add a warning under the substitutions table like so:

W> Note that `[chunkhash]` cannot be used in conjunction with "Watch Mode". For example, if you're using `webpack-dev-server` or `webpack-dev-middleware` during development, you will get an error using `[chunkhash]` within your development configuration.

[ematipico]

I get this error even on production build. I don't run any watcher or HMR thing.
I run the command

 webpack --config webpack.config.prod.js --optimize-minimize --colors --profile --progress

The output statement is the same of the one that I pasted before. I tried to reproduce it on another smaller repo but no joy. I guess there's a combination of settings that fires that error...

[ematipico]

Found the cause of that error, which is now filed here webpack/webpack#5337

I close the PR

[skipjack]

Awesome -- thanks @ematipico for following up on this!