Support Webpack 4.29.0 breaking change

[Jack-Works]

write-file-webpack-plugin/src/WriteFileWebpackPlugin.js

Line 168 in af0192e

// asset.size method returns `undefined` for binary files (e.g. WASM). This is a temporarily workaround.

If asset is an instance of SizeOnlySource, it will throw an error on any method except size

Breaking change: https://github.com/webpack/webpack/releases/tag/v4.29.0

• add output.futureEmitAssets which gives the emitting logic of webpack 5
• • assets are replaced with SizeOnlySources
• • reading assets after emitting is no longer allowed
• • This allows memory to be garbage-collected

Exception stack

Error: Content and Map of this Source is no longer available (only size() is supported)
    at SizeOnlySource._error (node_modules/webpack/lib/Compiler.js:647:10)
    at SizeOnlySource.source (node_modules/webpack/lib/Compiler.js:661:14)
    at getAssetSource (node_modules/write-file-webpack-plugin/dist/WriteFileWebpackPlugin.js:116:24)
    at node_modules/write-file-webpack-plugin/dist/WriteFileWebpackPlugin.js:201:27
    at node_modules/lodash/lodash.js:4911:15
    at baseForOwn (node_modules/lodash/lodash.js:2996:24)
    at node_modules/lodash/lodash.js:4880:18
    at Function.forEach (node_modules/lodash/lodash.js:9344:14)
    at handleAfterEmit (node_modules/write-file-webpack-plugin/dist/WriteFileWebpackPlugin.js:182:24)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:7:1)
    at AsyncSeriesHook.lazyCompileHook (node_modules/tapable/lib/Hook.js:154:20)
    at asyncLib.forEachLimit.err (node_modules/webpack/lib/Compiler.js:432:27)
    at node_modules/neo-async/async.js:2813:7
    at done (node_modules/neo-async/async.js:3521:9)
    at outputFileSystem.writeFile.err (node_modules/webpack/lib/Compiler.js:400:9)
    at MemoryFileSystem.writeFile (node_modules/memory-fs/lib/MemoryFileSystem.js:328:9)

[Jack-Works]

Workaround:
Set config.output.futureEmitAssets = false

But this behavior will be default in webpack 5

[Jack-Works]

Hold on! This doesn't get fixed!

Webpack will switch to this new behavior and we don't know if they will give us an option to fall back to the old behavior!!

[feorex]

@Jack-Works Correct path is:
config.output.futureEmitAssets=false

[septs]

// TODO webpack 5 remove futureEmitAssets option and make it on by default

https://github.com/webpack/webpack/blob/40755384bfe9725e3105e7b5f9becba2c43f2a5f/lib/Compiler.js#L374

Copy @gajus @feorex @Jack-Works

[kievsash]

In Angular cli 8.3 I got this error for ng build --prod

But ng build --prod --source-map=false worked for me

[lukeapage]

Note - this is removed in webpack 5 beta, so this plugin does not work in webpack 5.

[KevinGhadyani-minted]

I'm on Webpack 5. This plugin is broken for me :/.

[idflood]

It seems that this plugin is not needed anymore with webpack 5 (edit: since webpack-dev-server 3.1.10) 🎉

The webpack-dev-server now has a writeToDisk option and the same is available too with webpack-dev-middleware.

The middleware page even have this description:

If true, the option will instruct the module to write files to the configured location on disk as specified in your webpack config file. Setting writeToDisk: true won't change the behavior of the webpack-dev-middleware, and bundle files accessed through the browser will still be served from memory. This option provides the same capabilities as the WriteFilePlugin.

So thanks a lot @gajus for this excellent plugin, even if it's not needed anymore it will still be used for years to come in already existing projects :)