Turf does not work with Webpack 4

I upgraded my project to Angular 6 which migrated to Webpack 4. I have a dependency on mapbox which uses turf. After the upgrade I started getting build errors like the following.

ERROR in ./node_modules/@turf/meta/index.mjs
997:15-25 Can't import the named export 'lineString' from non EcmaScript module (only default export is available)
 @ ./node_modules/@turf/meta/index.mjs
 @ ./src/index.js

It appears to be failing because @turf/meta uses mjs and @turf/helpers is a non mjs module. I am not sure if this is just a build configuration in Webpack that needs to be tweaked or if a correction needs to be made to turf. I looked around the Webpack issues and didn’t really see anything to help along with a fix.

Here is a repo to easily reproduce this issue.

https://github.com/adamduren/webpack4-turf-issue

[ghost]

Downgrading from @turf/difference v6.0.2 to v6.0.1 worked for me. I deleted my node_modules folder to make sure no old files hung around.

[danwoods]

Could we get a similar fix for @turf/invariant? Hitting a similar issue when trying to use @turf/boolean-contains

ERROR in ./node_modules/@turf/invariant/index.mjs
59:34-42 Can't import the named export 'isNumber' from non EcmaScript module (only default export is available)
 @ ./node_modules/@turf/invariant/index.mjs
 @ ./node_modules/@turf/boolean-contains/index.js
 @ ./src/components/map/index.js
 @ ./src/util/app.js
 @ ./src/index.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server ./src/index.js react-hot-loader/patch

ERROR in ./node_modules/@turf/invariant/index.mjs
59:62-70 Can't import the named export 'isNumber' from non EcmaScript module (only default export is available)
 @ ./node_modules/@turf/invariant/index.mjs
 @ ./node_modules/@turf/boolean-contains/index.js
 @ ./src/components/map/index.js
 @ ./src/util/app.js
 @ ./src/index.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server ./src/index.js react-hot-loader/patch
ℹ ｢wdm｣: Failed to compile.