Fix displaying third party webpack plugins errors

[Fer0x]

Some third party webpack plugins can generate custom single-line compiler errors without stacktrace.

For example with html-webpack-plugin I got following error as formatMessage argument:

'Template execution failed: TypeError: Cannot read property \'main\' of undefined' 

As fast solution I propose to add empty line to avoid big changes in formatMessage logic.

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at cla@fb.com. Thanks!

[Timer]

Can you please give us a reproducing case that triggers this exact error? What exactly happens?

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[Fer0x]

@Timer
I have ejected react-scripts and now I try to upgrade to 2.x version.
I use custom html template where I use this line:

var scriptSrc = '<%= htmlWebpackPlugin.files.chunks.main.entry %>';

By some reasons files.chunks is not defined, but I can't see this error, instead I got following error:

  if (lines[1].indexOf(moduleWarningPrefix) === 0) {
               ^

TypeError: Cannot read property 'indexOf' of undefined
    at formatMessage (/Users/myproject/node_modules/react-dev-utils/formatWebpackMessages.js:44:16)
    at /Users/myproject/node_modules/react-dev-utils/formatWebpackMessages.js:169:12
    at Array.map (<anonymous>)
    at formatWebpackMessages (/Users/myproject/node_modules/react-dev-utils/formatWebpackMessages.js:168:37)
    at compiler.run (/Users/myproject/scripts/build.js:126:24)
    at finalCallback (/Users/myproject/node_modules/webpack/lib/Compiler.js:204:39)
    at hooks.done.callAsync.err (/Users/myproject/node_modules/webpack/lib/Compiler.js:253:14)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/Users/myproject/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:6:1)
    at AsyncSeriesHook.lazyCompileHook (/Users/myproject/node_modules/tapable/lib/Hook.js:154:20)
    at emitRecords.err (/Users/myproject/node_modules/webpack/lib/Compiler.js:251:22)
    at Compiler.emitRecords (/Users/myproject/node_modules/webpack/lib/Compiler.js:366:39)
    at emitAssets.err (/Users/myproject/node_modules/webpack/lib/Compiler.js:245:10)
    at hooks.afterEmit.callAsync.err (/Users/myproject/node_modules/webpack/lib/Compiler.js:352:14)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/Users/myproject/node_modules/tapable/lib/HookCodeFactory.js:32:10), <anonymous>:6:1)
    at AsyncSeriesHook.lazyCompileHook (/Users/myproject/node_modules/tapable/lib/Hook.js:154:20)
    at asyncLib.forEach.err (/Users/myproject/node_modules/webpack/lib/Compiler.js:349:27)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[Timer]

Excellent. Thank you.