import "!!file-loader? 是什么意思

https://webpack.js.org/concepts/loaders/#inline

Inline

It's possible to specify loaders in an import statement, or any equivalent "importing" method. Separate loaders from the resource with !. Each part is resolved relative to the current directory.

importStylesfrom'style-loader!css-loader?modules!./styles.css';

It's possible to override any loaders, preLoaders and postLoaders from the configuration by prefixing the inline import statement:

Prefixing with ! will disable all configured normal loaders

importStylesfrom'!style-loader!css-loader?modules!./styles.css';

Prefixing with !! will disable all configured loaders (preLoaders, loaders, postLoaders)

importStylesfrom'!!style-loader!css-loader?modules!./styles.css';

Prefixing with -! will disable all configured preLoaders and loaders but not postLoaders

importStylesfrom'-!style-loader!css-loader?modules!./styles.css';

Options can be passed with a query parameter, e.g. ?key=value&foo=bar, or a JSON object, e.g. ?{"key":"value","foo":"bar"}.

Use module.rules whenever possible, as this will reduce boilerplate in your source code and allow you to debug or locate a loader faster if something goes south.