### Version 14.2.1 ### Reproduction link [https://github.com/scry/VueCoverage](https://github.com/scry/VueCoverage) ### Steps to reproduce clone the repo, yarn install, karma start. Karma will break because of [these lines](https://github.com/SitePen/remap-istanbul/blob/master/src/CoverageTransformer.js#L142-L143) in remap-istanbul. remap-istanbul expects sourcemaps to have the "file" property, but vue-loader isn't setting it. ### What is expected? parser.js should be passing the file option to SourceMapGenerator, as per [SourceMapGenerator docs](https://www.npmjs.com/package/source-map#with-sourcemapgenerator-low-level-api). [Link to line in vue-loader.](https://github.com/vuejs/vue-loader/blob/master/lib/parser.js#L41) ### What is actually happening? parser.js skips the file property, which results in a map being exported without file specified. --- This causes an issue specifically with remap-istanbul. I thought the bug was theirs for a while but it looks like it's a saner fix in vue-loader. <!-- generated by vue-issues. DO NOT REMOVE -->