Error in webpack-sources

Do you want to request a feature or report a bug? bug

What is the current behavior? TypeError: item.source is not a function

TypeError: item.source is not a function
    at /Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/ConcatSource.js:23:50
    at Array.map (native)
    at ConcatSource.source (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/ConcatSource.js:22:24)
    at /Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/ConcatSource.js:23:50
    at Array.map (native)
    at ConcatSource.source (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/ConcatSource.js:22:24)
    at /Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/ConcatSource.js:23:50
    at Array.map (native)
    at ConcatSource.source (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/ConcatSource.js:22:24)
    at CachedSource.source (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/webpack-sources/lib/CachedSource.js:28:44)
    at Compiler.writeOut (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/lib/Compiler.js:346:27)
    at require.forEach (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/lib/Compiler.js:336:21)
    at /Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/async/dist/async.js:3083:16
    at eachOfArrayLike (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/async/dist/async.js:1003:9)
    at eachOf (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/async/dist/async.js:1051:5)
    at Object.eachLimit (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/node_modules/async/dist/async.js:3145:5)
    at Compiler.emitFiles (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack/lib/Compiler.js:325:21)
    at Immediate.<anonymous> (/Users/u_021ly/Desktop/projects/arui-feather/node_modules/webpack-dev-middleware/node_modules/memory-fs/lib/MemoryFileSystem.js:288:4

This is Travis build https://travis-ci.org/alfa-laboratory/arui-feather/jobs/255237762#L718 If the current behavior is a bug, please provide the steps to reproduce.

git clone https://github.com/alfa-laboratory/arui-feather.git
git checkout feat/add-md-lint
npm i
npm run gemini-ci

What is the expected behavior? Runs without errors. If this is a feature request, what is motivation or use case for changing the behavior?

Please mention other relevant information such as the browser version, Node.js version, webpack version and Operating System. npm -v 5.3.0 node -v 6.10.1 webpack 3.3.0

[nowells]

So I stumbled into this issue a while ago, and discovered it was not webpack’s fault at all, but instead a dependency’s dependency that was loading a poorly written poly/ponyfill library that instead of adding JS functions/features that were missing (like adding Array.from if not defined) they instead ALWAYS replaced Array.from, Map, etc. with bad implementations. For example, my issue was pulling in q-io which pulled in the collections npm package that poorly clobbers JS builtins in a really bad way.

[ooflorent]

Thanks @nowells and @1more for your investigation on this issue! I’m closing it since it is not webpack’s fault.