[4.0.0-alpha.0] Cannot read property 'moduleExports' of undefined

[tzimmermann]

I get TypeError: Cannot read property 'moduleExports' of undefined after upgrading to webpack 4 and the new alpha of the extract-text plugin:

"extract-text-webpack-plugin": "4.0.0-alpha.0",
"webpack": "4.0.0"

The stack trace points to .chunkModule.source() being called without parameter here, which leads to the runtime variable being undefined here

This looks like the same line is causing this as in #722.

EDIT: I can confirm that the issue is related to dynamic module loading: If I remove all dynamic import statements, the error goes away (see #722 (comment))

Here's the full stack trace:

/Users/tz-mac/Repos/pex-client/node_modules/webpack/lib/DelegatedModule.js:66
                        str = `module.exports = (${runtime.moduleExports({
                                                          ^

TypeError: Cannot read property 'moduleExports' of undefined
    at DelegatedModule.source (/Users/tz-mac/Repos/pex-client/node_modules/webpack/lib/DelegatedModule.js:66:38)
    at Function.renderExtractedChunk (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/dist/index.js:115:38)
    at ExtractTextPlugin.extractedChunks.forEach.extractedChunk (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/dist/index.js:298:46)
    at Array.forEach (<anonymous>)
    at compilation.hooks.additionalAssets.tapAsync.assetCb (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/dist/index.js:286:25)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/Users/tz-mac/Repos/pex-client/node_modules/tapable/lib/HookCodeFactory.js:24:12), <anonymous>:7:1)
    at AsyncSeriesHook.lazyCompileHook [as _callAsync] (/Users/tz-mac/Repos/pex-client/node_modules/tapable/lib/Hook.js:35:21)
    at hooks.optimizeTree.callAsync.err (/Users/tz-mac/Repos/pex-client/node_modules/webpack/lib/Compilation.js:939:32)
    at _err0 (eval at create (/Users/tz-mac/Repos/pex-client/node_modules/tapable/lib/HookCodeFactory.js:24:12), <anonymous>:11:1)
    at _async2.default.forEach.err (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/dist/index.js:281:11)
    at /Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/node_modules/async/dist/async.js:421:16
    at iteratorCallback (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/node_modules/async/dist/async.js:998:13)
    at /Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/node_modules/async/dist/async.js:906:16
    at _async2.default.forEach.err (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/dist/index.js:259:13)
    at /Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/node_modules/async/dist/async.js:421:16
    at iteratorCallback (/Users/tz-mac/Repos/pex-client/node_modules/extract-text-webpack-plugin/node_modules/async/dist/async.js:998:13)

[kaiyoma]

I'm also running into issues when trying to upgrade to webpack 4.0. yarn check spits this out:

error "extract-text-webpack-plugin#webpack@^3.1.0" doesn't satisfy found match of "webpack@4.0.0"

[michael-ciniawsky]

@kaiyoma

npm i -D extract-text-webpack-plugin@next

extract-text-webpack-plugin@3.0.0 will 💯 break with webpack >= v4.0.0 :)

[Jessidhia]

This is related to #722; the difference being that this also involves DllPlugin.

[michael-ciniawsky]

Released in v4.0.0-beta.0 🎉

[tzimmermann]

@michael-ciniawsky Thanks a lot, working now for me, too!