Jest: TypeError: Cannot read property 'length' of undefined

[binarykitchen]

Since I switched to io.js v1.8.1 I get plenty of these errors:

TypeError: Cannot read property 'length' of undefined
  at maybeReadMore_ (_stream_readable.js:425:18)
  at /home/xxx/node_modules/gulp-jest/node_modules/jest-cli/src/lib/FakeTimers.js:325:7
  at process._tickCallback (node.js:341:15)

[sogko]

+1

This error manifests itself if a __tests__ folder has more than one test file in it.

It works as expected if there is only one test file in the __test__ folder.

io.js v1.8.1 as well with babel preprocessor
jest v0.4.0

Edit:
seems like jest doesn't play nice with io.js yet (re: #243)

[seanchen1991]

@sogko I receive this error even when I have only one test per tests folder, though I have multiple tests folders throughout my project.

[nkashyap]

+1 same issue for me
io.js v 2.0.1
jest v0.4.3

[lfilho]

+1

iojs 1.8.1
jest 0.4.5

[lfilho]

Also happend on

iojs 2.1.0
jest 0.4.5

[geirsagberg]

+1

iojs 2.3.1
jest-cli 0.4.13

[mattotodd]

If you would like to use jest with io.js, you will need to use the 0.5.x branch of the jest-cli

npm install facebook/jest#0.5.x

found via https://github.com/facebook/jest/issues/243#issuecomment-114989511
and fixed the issue for me

[lfilho]

thanks, @mattotodd ! I've given up on Jest for the project I'm working on, but I'll keep that in mind for next time I try Jest.

Thanks for taking the time to post this here!

[binarykitchen]

https://github.com/binarykitchen/gulp-jest-iojs might be useful ...

[bhanubhakta]

@mattotodd npm WARN package.json @ No repository field while using npm install facebook/jest#0.5.x

[kreigne]

+1

[cpojer]

This is fixed in 0.5.