TypeError: Cannot set property 'tsLoaderFileVersion' of undefined

Expected Behaviour

Build to work when happypackmode is not set

Actual Behaviour

Transpilation fails with following error message

ERROR in ./somefile.ts
Module build failed: TypeError: Cannot set property 'tsLoaderFileVersion' of undefined
    at successLoader (C:\sources\gitttl\gsk\MeetingWorkspace\node_modules\ts-loader\dist\index.js:47:54)
    at Object.loader (C:\sources\gitttl\gsk\MeetingWorkspace\node_modules\ts-loader\dist\index.js:21:12)

Steps to Reproduce the Problem

Have a project with webpack 3, ts-loader@latest, and happypackmode not set.

Location of a Minimal Repository that Demonstrates the Issue.

[hrgui]

Same here, Webpack 3.8.1, I had to revert back to v3.3.1 in order to get this resolved.

Also note that ts-loader v4 and above does not support Webpack 3 as mentioned in v4 release notes.

[johnnyreilly]

If there’s a simple (non-hacky) way to reliably test the webpack version I’m open to adding a “your webpack version is not supported - use webpack 4 or and older version of ts-loader”. Otherwise I think it’s best left as is.

This was intentionally a breaking changes release and TBH people should take a look at release notes if they are hoping to make a major version bump. Not trying to be difficult. Just trying to be a good semver citizen.