Invalid sourcemaps in dist/

Q&A (please complete the following information)

• OS: Windows
• Browser: NA
• Version: latest (master branch)
• Method of installation: NA
• Swagger-UI version: latest (master branch)
• Swagger/OpenAPI version: NA

Describe the bug you're encountering

The .map files provided in the dist/ folder seem to be invalid, based on sourcemap-validator

To reproduce...

Steps to reproduce the behavior:

1. Install the sourcemap-validate command:
   npm install -g git+https://github.com/Lucas-C/sourcemap-validator.git
2. Execute the following command in this repo:
   sourcemap-validate dist/swagger-ui-bundle.js dist/swagger-ui-bundle.js.map

Expected behavior

Validation OK

Additional context or thoughts

Using sourcemap-validate I tested that the Validation OK message appears up to tag v3.3.0. Starting from tag v3.4.0 the error appears.

I found about this error in https://github.com/springfox/springfox/issues/3114, because my Firefox browser could not load the sourcemaps correctly.

Based on the package-lock.json in this repo I cannot pinpoint exactly what version of webpack-sources it is using, but this error may be due to a nasty bug broke sourcemaps it generated before version 1.4.1

Start by running sourcemap-validate against dist/swagger-ui-bundle.js and dist/swagger-ui-bundle.js.map, then inspect package-lock.json and the build configuration for the webpack-sources version used since v3.4.0. Done means the generated .map files validate successfully and the command reports "Validation OK".