Get an error if HMR and hot together

[a-dev]

I had an trouble in a project that hotModuleReplacement didn't work, got an error 'Maximum call stack size exceeded'.
It's an old issue that flag --hot and hotModuleReplacement can't be together.

I removed HotModuleReplacementPlugin() form config:

if (devServer.hmr) {
  this.plugins.append('HotModuleReplacement', new webpack.HotModuleReplacementPlugin()) // remove this line and HMR will work
  this.config.output.filename = '[name]-[hash].js'
}

I use last versions:
"webpack": "^4.35.0",
"webpack-dev-server": "^3.7.2",

[jakeNiemiec]

Does it work if you omit ‘—hot’? It should work if you just set devServer.hot: true.

[babel92]

Ran into similar issue after upgrading from 4.0.2 to 4.0.3. webpack-dev-server actually checks for this plugin but somehow it failed (https://github.com/webpack/webpack-dev-server/blob/802aa30cc0a549803e64b74a7085a2c549c71f41/lib/utils/updateCompiler.js#L18)

[a-dev]

Does it work if you omit ‘—hot’? It should work if you just set devServer.hot: true.

@jakeNiemiec If you set hmr: true you already have a ‘--hot’, cause hot: devServer.hmr,
see here https://github.com/rails/webpacker/blob/master/package/environments/development.js

[jakeNiemiec]

What issue are you having? We can only fix problems with rails/webpacker here.

[a-dev]

I just sad that you have the flag hot: true and append HotModuleReplacement if hmr: true in yml config. But it can make error, cause it isn’t necessary to append HotModuleReplacement if —hot option omitted.

[jakeNiemiec]

it can make error, cause it isn’t necessary to append HotModuleReplacement if —hot option omitted

I would think that the solution is: just don't append the HotModuleReplacement plugin. I also would not use both the --hot flag with webpacker.

Does removing the HotModuleReplacementPlugin() from your config fix things?

[a-dev]

@jakeNiemiec I don’t have HotModuleReplacementPlugin() in my config, it’s in the config of Webpacker. And I showed in this issue (first post) if you remove appending of HotModuleReplacementPlugin() you fix this error.
In Webpacker config it’s here — https://github.com/rails/webpacker/blob/master/package/environments/development.js#L11

[jakeNiemiec]

Apologies, the link from @babel92 completely threw me off. How are you invoking webpack with --hot? (I assume something like ./bin/webpack-dev-server --hot)

[babel92]

Actually I think @a-dev and I are having the same issue - if you set hmr: true in webpacker.yml, webpacker inserts HotModuleReplacementPlugin and uses hot: true to launch webpack-dev-server (which should be equivalent to --hot option). And webpack-dev-server would try to check for this plugin before inserting it again but it failed to identify it somehow in our cases. My suggestion was just don't append this plugin in @rails/webpacker as a-dev already proposed, given webpack-dev-server will do that anyway.

[justin808]

I submitted a PR to fix this: #2439.

[justin808]

@gauravtiwari can you reopen: #2439

I think given the docs clearly state that this is correct, we should consider #2439.

[justin808]

@guillaumebriday Let's close and let somebody reopen if an issue with v6.