[CLI] Adds Testing to CLI

[tommymchugh]

This PR adds the necessary testing to the install command for the cli.

Testing checks for: Podfile existing, Containing React-Native Tags, and for React Pod to be included.

[frantic]

Why did you close this? I don't know if we have this in the docs, but to run the tests do

$ npm test

we use Jest for testing, but unfortunately it doesn't work on node version above 0.10. I use n to switch node binaries, but it's up to you.

Also I believe in order for Jest to find your test it has to be named moduleYouTesting-test.js (at least that's our convention)

[frantic]

fs.existsSync

[tommymchugh]

@frantic Ahh that makes sense, some of it was failing in Travis CI, but working when doing npm test, so I'll figure that out and commit.

[frantic]

@tommchugh I think the problem is in using current dir in both tests and code. cwd() is super unreliable and often leads to weird bugs. Prefer passing around absolute paths and using path.resolve and friends with __dirname, __filename.

For example, your install function can take root as param. In your tests, you can create fake files to simulate different layouts (with or without Podfile, with or without node_modules, etc.). But cli.js will invoke install function with real root dir (either by passing cwd() or __dirname, etc.)

[tommymchugh]

@frantic Yep that looks like it. All is well with Travis.

[brentvatne]

@frantic - is this still relevant? seems like a clean merge still if not 😄

[sahrens]

We have a nice end-to-end test, so not sure if still relevant - @frantic: can you either close out or review if you want it?

[sahrens]

Actually Tadeu's been looking at this stuff more lately and frantic is on vacation...

[tadeuzagallo]

yaytests

Tests are always relevant! 😄
Just re-triggering travis since a lot has changed in the mean time.