Incompatibility with node fs api.

[alexander-akait]

I'm not sure this is bugs or expected behavior.
Example: fileSystem.readFileSync(filename, "utf8"), not respect utf8 and always return Buffer.

[TheLarkInn]

What version of node did you see this?

[alexander-akait]

@TheLarkInn i see function as in fs module (readFileSync and etc), It would be nice to have compatibility them with nodejs fs.
Original issue: babel/babel-loader#460 , maybe give more information.

[mhink]

@TheLarkInn I ran into this as well. (For reference, the error I was seeing is the same as this one in CopyWebpackPlugin: webpack-contrib/copy-webpack-plugin#217)

The incompatibility is in this method call (and others like it)

https://github.com/webpack/enhanced-resolve/blob/master/lib/CachedInputFileSystem.js#L238

The method signature here is readFile(path, callback), but Node's fs methods have the signature readFile(path, options, callback) as documented in the following:

https://nodejs.org/dist/latest-v8.x/docs/api/fs.html#fs_fs_readfile_path_options_callback

So if you're doing something like fs.readFile(pathToMyFile, "utf8", callback), CachedInputFileSystem tries to invoke "utf8" as a callback, and throws:

TypeError: callbacks[i] is not a function

[rjgotten]

Hitting this as well in the context of writing a loader for Webpack.

Really annoying and makes it awfully tempting to sidestep the formally correct this.fs and just directly hit the raw Node.js internal fs module instead.

[alexander-akait]

Fixed before, improved here #254