Is there any other way than looking up an environment variable to figure this out?

We should not rely on this, always use compiler.outputFileSystem, because webpack uses compiler.outputFileSystem to write assets, so you can read them using the same fs

Hey @alexander-akait, I am unable to do this directly without webpack-dev-server check

this.fs = compiler.outputFileSystem

because of this

Otherwise,

will break the tests

and this is webpack v4 specific

hm, for webpack v5, we have these methods? I mean use compiler.outputFileSystem for webpack v5, and keep old behavior for webpack v4

I see

It means we write file again, need debug and search where we do it

the implementation of MemoryFS does not support recursively create folder. See this

according to the package-lock.json, the version of memory-fs is using 0.4.1

memory-fs used only by webpack@4, we should use require('fs') for webpack v4

Ok. I did what you have suggested and fixed the file already exist issue

I still need you help for the test. I have updated dev-server.js. For some reason, I am unable to get the test passed for {writeToDisk: true}.

It always use MemoryFileSystem and I do not know how to fix

So, logLevel option won't work anymore?

As the launch is always from webpack, it will use webpack.config.js level setting. See https://v4.webpack.js.org/configuration/stats/#statslogging and https://webpack.js.org/configuration/stats/#statslogging

bin/analyzer still can have its own log level

We need to update readme in this case and remove logLevel option from this list as it will be ignored.

I have just realized for webpack compiler without using hooks, it will fallback to your own logger. I do not know which version is not using hooks

Almost complete. This is the test I was talking about in our long conversation with @alexander-akait. And I need some help for this one. Currently, I skip because I do not want to waste the time in the build machine.

What is the problem here?

When I specific devServer: { writeToDisk: true } in the webpack.config.js, it should output to disk. But it is still in the memoryFS because of the following, it always go to the last else statement

I have just figured out the reason why it always output to MemoryFileSystem when {writeToDisk: true}. webpack-dev-middleware is using compiler.hooks.assetEmitted when a file is assetEmitted to MemoryFileSystem, it will also emit to disk. But webpack-bundle-analyzer is not emitting the report.html or stats.json via the compiler.emitAssets So it never output to disk

The correct logic should be this

this.fs = compiler.webpack ? compiler.outputFileSystem : require('fs');

if ((process.env.WEBPACK_DEV_SERVER === 'true' || process.env.WEBPACK_SERVE === 'true')
  && (compiler.options.devServer?.writeToDisk || compiler.options.devServer?.devMiddleware?.writeToDisk)) {
  this.fs = require('fs');
}

No, it is not problem with webpack-bundle-analyzer, webpack-dev-middleware for the writeToDisk option should create layer fs, it is already tracked, no need to change something here

Then how to get {writeToDisk: true} works if it is not the problem?