sourceAndMap
Source.prototype.sourceAndMap(options?: Object) -> {
source: String | Buffer,
map: Object | null
}
Returns both, source code (like Source.prototype.source() and SourceMap (like Source.prototype.map()). This method could have better performance than calling source() and map() separately.
See map() for options.
https://github.com/webpack/webpack-sources/blob/9ec78f2ef3d9169293636c48b7741ebb7b457ac6/lib/helpers.js#L23
Documents write:
Can you explain it ? thx