jest-cli version 0.5+ won't work with current version of Node; should require jest-cli <0.5

[jmrog]

This isn't an issue with any of the code itself, but it's still an issue that I encountered while working through the book. Posting it here may help others. (It might be also be worth posting a correction to the book's text that makes jest-cli <0.5 a requirement.)

For the tests in Chapter 8, the book uses jest-cli version 0.4.18. However, the current version of jest-cli is 0.5.1, and version 0.5.1 is what will be installed if you enter the exact command presented in Chapter 8 (npm install –-save-dev jest-cli). The major problem here is that any version of jest-cli greater than 0.4 will not support the current version of Node.js (0.12), or any version below that (see this link for some discussion: jestjs/jest#243), and therefore the tests in the book will not work at all. The simplest solution, if you are using Node (and not io.js), is to force installation of jest-cli < 0.5, using a command like this:

npm install --save-dev jest-cli@^0.4

This will install a version of jest-cli >=0.4 and <0.5, and all should work from there.

[fedosejev]

@jmrog thanks for your correction. I will improve this update: https://github.com/fedosejev/react-essentials/blob/master/updates.md#chapter-8-page-6

[jmrog]

Oops! I missed that you posted that update. What you have there is fine, and should fix the issue I mentioned. This can be closed.