Webpack 5 warns about a deprecation in watch mode

[cowwoc]

webpack-stream 6.1.0
webpack 5.4.0

I've successfully used this plugin with a custom Webpack 5 compiler passed in as the second argument. One thing I am unable to get working is "watch mode". If I take a working webpack configuration and add watch = true then Webpack fails with:

(node:28480) [DEP_WEBPACK_WATCH_WITHOUT_CALLBACK] DeprecationWarning: A 'callback' argument need to be provided to the 'webpack(options, callback)' function when the 'watch' option is set. There is no way to handle the 'watch' option without a callback.
    at webpack (C:\Users\cowwoc\Documents\holdmyspot\shopping\client\browser\node_modules\webpack\lib\webpack.js:145:5)
    at f (C:\Users\cowwoc\Documents\holdmyspot\shopping\client\browser\node_modules\webpack\lib\index.js:35:15)
    at Stream.<anonymous> (C:\Users\cowwoc\Documents\holdmyspot\shopping\client\browser\node_modules\webpack-stream\index.js:150:38)
    at _end (C:\Users\cowwoc\Documents\holdmyspot\shopping\client\browser\node_modules\through\index.js:65:9)
    at Stream.stream.end (C:\Users\cowwoc\Documents\holdmyspot\shopping\client\browser\node_modules\through\index.js:74:5)
    at module.exports (C:\Users\cowwoc\Documents\holdmyspot\shopping\client\browser\node_modules\webpack-stream\index.js:225:12)

I get this when invoking:

gulpWebpack(config, compiler, function(err, stats)
		{
			if (err)
				throw err;
			console.log(stats);
		}))

where config includes watch=true.

Oddly, I don't get this warning if I invoke webpack.watch() directly without this plugin.

[cowwoc]

Not a bug. See #109 followed by https://github.com/shama/webpack-stream#usage-with-gulp-watch

[cowwoc]

Reopening. Per #18 (comment) the approach in #109 is 10x slower than webpack.watch().

We need to resolve the deprecation warning mentioned above.

[cowwoc]

@shama I think I figured it out. If you invoke:

const compiler = webpack(config);
compiler.watch({}, callback);

where config does not contain watch: true then webpack does watch the files because you invoked the watch() method explicitly. If I leave watch: true in config then webpack issues the aforementioned warning.

One way you could fix this bug is to simply strip watch: true from config before passing it on to webpack. Users will still need to pass watch: true to this plugin so it knows to invoke compiler.watch() but you will need to strip it out before passing the config to webpack. Makes sense?

[cowwoc]

@shama I tested #231 locally. It fixes the deprecation warning for me. Please review and merge if you agree.